rowville rail study preliminary rail design report final

Preliminary Rail Design

Report

December 2012

This document forms part of the Rowville Rail Feasibility Report and should be read in the context of the broader report. The study teams, including SKM, Mott MacDonald, Hassell and Phoenix Facilitation, have prepared this report following appointment by the Victorian State Government.

The Rowville Rail Feasibility Report is a study investigating the feasibility of a heavy rail line from Rowville connecting into the existing train network at Huntingdale Station on the Pakenham/Cranbourne lines. This is Phase 1 of a two part study investigating initial engineering, architectural, environmental and operational considerations. It has also included consultation with the community and stakeholders through various methods.

The overall Rowville Rail Feasibility Report is made up of 9 parts:

Main report Preliminary rail design report Travel demand modelling report Sustainability considerations report Environment and planning investigation report Station layout and urban design report Consultation report Concept timetabling and operations report Final submissions report

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Table of Contents

1. Engineering Summary ................................................................................................... 5

2. Design Brief .................................................................................................................... 6

3. Basis of Design .............................................................................................................. 6

4. Physical constraints and opportunities ...................................................................... 7

5. Alignment Options ....................................................................................................... 10

6. Alignment Option Selection ........................................................................................ 13

7. Civil Structures Required ............................................................................................ 30

7.1 Introduction ...................................................................................................... 30

7.2 Tunnel cross section requirements .................................................................. 34

7.3 Cut-and-cover tunnel ........................................................................................ 36

7.4 Open Cut .......................................................................................................... 38

7.5 Elevated Sections (Viaduct) ............................................................................. 41

7.5.1 Typical Design Elements ............................................................................ 42

7.5.2 Elevated Station Design .............................................................................. 47

7.5.3 Approach Ramps and Tunnel Portals ......................................................... 49

7.5.4 Trackform .................................................................................................... 49

7.5.5 Design issues .............................................................................................. 49

7.5.6 Construction Issues .................................................................................... 53

7.6 Bridges ............................................................................................................. 57

7.6.1 Princes Highway grade separation ............................................................. 57

7.6.2 Monash Freeway grade separation ............................................................ 57

7.6.3 East Link grade separation, Alignment A or A* ........................................... 57

7.6.4 East Link grade separation, Alignment C .................................................... 57

7.7 Sprayed Concrete Lined Tunnel ...................................................................... 58

7.8 TBM Bored tunnel ............................................................................................ 62

7.8.1 General Principles ....................................................................................... 62

7.8.2 Twin tunnels versus single bore .................................................................. 64

7.9 Station design .................................................................................................. 66

7.9.1 Underground Stations ................................................................................. 66

7.9.2 Elevated Stations ........................................................................................ 67

7.10 Fire and Life Safety .......................................................................................... 68

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7.10.1 Fire Engineering Process ............................................................................ 68

7.10.2 Applicable Legislation & Standards ............................................................ 68

7.10.3 Principal Characteristics ............................................................................. 69

7.10.4 Fire Safety Objectives ................................................................................. 70

7.10.5 Fire Hazards & Risks .................................................................................. 70

7.10.6 Concept Requirements -Tunnels ................................................................ 71

7.10.7 Concept Requirements - Stations ............................................................... 72

7.11 Ventilation Concepts ........................................................................................ 74

7.11.1 Tunnel Ventilation System .......................................................................... 74

7.11.2 Station Ventilation ....................................................................................... 74

7.11.3 Public and Back of House Areas ................................................................ 75

7.11.4 Incident Ventilation Operations ................................................................... 75

7.12 Drainage ........................................................................................................... 78

8. Signalling ...................................................................................................................... 79

8.1 Basis of Design ................................................................................................ 79

8.2 Existing infrastructure ....................................................................................... 79

8.3 Implementing new Rowville Rail Link ............................................................... 80

9. Traction Power and Overhead Line Electrification ................................................... 84

9.1 Power ............................................................................................................... 84

9.1.1 Tie Stations ................................................................................................. 84

9.1.2 Substations ................................................................................................. 84

9.1.3 Rowville Line Power Requirements ............................................................ 85

9.2 Electrolysis ....................................................................................................... 86

9.3 Overhead ......................................................................................................... 87

9.3.1 Conductors .................................................................................................. 88

9.3.2 Interface with Dandenong corridor .............................................................. 88

9.3.3 Open route .................................................................................................. 88

9.3.4 Elevated and viaducts ................................................................................. 89

9.3.5 Tunnels and restricted space ...................................................................... 89

9.3.6 Stabling ...................................................................................................... 95

10. Railway Communication ............................................................................................. 96

11. Constructability .......................................................................................................... 99

11.1 Project Timeline ............................................................................................... 99

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11.2 Noise and vibration impacts ............................................................................. 99

11.3 Temporary access Shafts .............................................................................. 100

11.3.1 Cut and Cover Tunnel ............................................................................... 100

11.3.2 Road Header Tunnel ................................................................................. 100

11.3.3 TBM Tunnel .............................................................................................. 100

11.4 Construction Method ...................................................................................... 101

11.4.1 Overall Alignment Considerations ............................................................. 101

11.4.2 Station areas ............................................................................................. 101

11.4.3 Below Ground Alignment .......................................................................... 105

11.4.4 Viaducts .................................................................................................... 112

11.4.5 Railway Infrastructure (Tracks, Power and Signalling) ............................. 113

11.5 Work Sites ...................................................................................................... 113

11.6 Traffic Management ....................................................................................... 115

11.6.1 Huntingdale Station Precinct ..................................................................... 116

11.6.2 North and Wellington Roads ..................................................................... 117

11.6.3 Stud Road and Rowville Station Precinct.................................................. 117

11.6.4 Major Road Crossings .............................................................................. 117

11.7 Maintenance Access Requirements ............................................................... 118

11.8 Protection of Operational Rail Infrastructure .................................................. 118

11.9 Operational Requirements ............................................................................. 120

11.10 Rail, Road and Pedestrian Protection Measures ........................................... 120

12. Railway Operational Safety ....................................................................................... 122

13. Operational Maintenance .......................................................................................... 122

14. Developments from Previous Report ...................................................................... 123

14.1 Knox City Council report Rowville Railway Pre-Feasibility Study 2004 ......... 123

15. Conclusion ................................................................................................................. 125

Appendix A: Civil structures

Appendix B: Signalling Schematic

Appendix C: Overhead Line and Power Schematic

Appendix D: Project Timeline

Appendix E: Tunnelling Advice

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Appendix F: Geotechnical Report

Appendix G: Utilities Information

Appendix H: Alignment Drawings

Appendix I: Flood Levels

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1. Engineering Summary

This report is based on a through suburban electric train service between Melbourne CBD and Rowville. The alignment generally follows Wellington Road, with two options shown for the approach to Rowville. Buried and elevated track would require engineering structures with options for these presented in the report, and a number of alternative vertical alignment options are shown on the alignment drawings.

The issues relating to the construction phase are reviewed, and ideas for managing these are documented.

From Huntingdale station towards Rowville, on leaving Huntingdale the Rowville line is shown located underground under the North Road flyover. Demolition of a small area of existing buildings on the south side of North Road would be required, unless a short length of mined tunnel is used, or a reduced radius curve with corresponding reduced line speed. The report discusses high level engineering options for the redeveloped Huntingdale Station.

Along North Road to Monash Station the central median generally provides suitable corridor width for open cut construction, with bridges to provide road crossings. Cut and cover construction would provide additional amenity value at ground level.

To the east of Monash Station the ground level drops relatively sharply, indicating viaduct construction as appropriate on track alignment grounds. The viaduct would extend to the east of Mulgrave Station. From there the alignment descends below ground level on the east side of the Monash Freeway.

High ground, and the need to remove a ‘peak’ in the track alignment, require the track to pass below ground level at Waverley Park Station. The tunnel emerges from the ground onto viaduct, on the north side of Wellington Road, adjacent to Jacksons Road, before the Dandenong Valley Parklands.

Two main options exist for the approach to the terminal station – across the Dandenong Creek flood plain crossing beneath Stud Road into the Stud Park shopping centre area, or alternatively following Wellington Road below ground, curving northwards at Stud Road. An alternative location for Rowville station on the corner of Wellington and Stud Roads has also been considered.

Buried and elevated structures would be required to account for ground topography and other alignment constraints. At this stage of the design process, it is considered feasible for cut and cover construction methods to be used for a large majority of the route requiring buried track. However, alternatives are considered in this report. Precast concrete viaduct is suggested for the elevated structure.

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Timescales for construction are anticipated to be in the order of four years from start of site works to commissioning, with a significant lead-in period for design, procurement and planning. Temporary lane closures or diversions would most likely be required in order to provide sufficient space for construction operations.

2. Design Brief

The Department of Transport document ‘Feasibility Study for the proposed Rowville Rail Line, Study Brief’, 25 March 2011 in conjunction with the SKM document ‘Technical Investigation Plan – Rowville Rail Study’, 29 June 2011, form the brief for this report.

3. Basis of Design

The following functionality and other requirements have been used in this engineering study: The proposed Rowville Railway line will provide a high quality heavy rail link to Monash

and Knox communities The project will support new services from Huntingdale to Rowville via Monash

University Dual Tracks to be provided from Huntingdale to Rowville May be constructed in stages Stabling and turn-back facilities to be addressed Options for connection to the Dandenong rail corridor at Huntingdale and track

configurations Existing structures to be assessed at high level It is desirable that the line between Huntingdale and Rowville should cater for an

operational speed of at least 130km/h and 80km/h through tunnels Minimum three trains per hour initially, with provision for 6 trains per hour as the

Dandenong Corridor is upgraded Normal standards apply for track geometry including: maximum track gradient 2%

generally and 0.66% at stations for straight track Construction timescale to be addressed Consideration needed for the natural and built environments, and sustainability Maintain, in some form, the existing pedestrian and cycle functionality currently located

in the central reserve between Huntingdale station area and Clayton Road, or state reasons why this is not possible

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4. Physical constraints and opportunities

The alignment lies generally in an existing well developed urban setting with many roads potentially intersected by the track alignment. Therefore, the alignment would be predominantly on viaduct or below ground. The alignment drawings are shown in Appendix H.

Set out in the following table is a summary of the significant physical constraints to the rail alignment along the route.

Significant physical constraints along the track alignment from

West to East

Constraint Implication for alignment

Rail connection to Dandenong rail corridor

Rail connection should provide a grade separated junction, with the Rowville track profile either over or under the existing Dandenong tracks

Suitable location of Huntingdale station post commissioning Rowville line

Rowville tracks connecting into the Dandenong line using an elevated grade separated alignment would require the Rowville platforms to be located approximately 200m north (towards Melbourne) than the existing platforms, this is probably too far for a reasonable interchange with busses. Rowville tracks connecting via a below ground alignment would enable the Rowville platforms to be located below but in the same plan location as the existing station Redevelopment of the station would be required for either option

Future Dandenong Rail Corridor rail lines

The alignment does not preclude, at high level concept stage, possible future tracks which may be provided as part of upgrade works which are currently undefined

North Road Flyover Major highway bridge immediately South of Huntingdale Station

This road bridge constrains the option of an elevated departure from Huntingdale station. New elevated track should lie on north side of North Rd to avoid extreme elevation required to cross the flyover. This would require property acquisitions. The elevated structure span over the North Road northern (eastbound) approach road would be at a skew requiring orthogonal cross spans or a single span of approximately 100m. New track passing to the south of the flyover should be at-grade or below ground level, to avoid clashes with existing infrastructure. The foundations for the flyover structure would require protection and may affect the alignment

Oakleigh Army Barracks The barracks fronting North Road may constrain the ability to construct shallow tunnel – they may require demolition and re-construction, or a smaller radius curve to avoid them. The small commercial single storey building at 1340 North Road is similarly a constraint.

High ground on East side of Princes Highway

Creates significant incline for track from Huntingdale Station to Princes Highway that, due to steep topography, precludes use of viaduct along this section and indicates track should be below ground level.

Road median width east of Monash University station area

The below ground railway breaks ground at this area, it is desirable that the portal structure fits within the median width. Local road lane reconfigurations may be required

Undulating ground between Variable height viaduct, or variable depth buried structure, to smooth peaks

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West to East Blackburn Road and Monash Freeway

and troughs to minimise power requirement

Monash Freeway and Wellington Road flyover

Track level to match Wellington Road as cannot be lowered as would impact major bridge and Monash Freeway Track level above road would not accomplish any useful end

High ground on East side of Monash freeway

To avoid excessive gradients, track must be below ground. The track would be at significant depth below ground to provide gradient on east side meeting standards A station in this area would have platforms below ground

Jacksons Road Important right turn provision exists at this junction, which coincides with the location that the rail line breaks ground

Dandenong Creek flood plain Flood level and freeboard requirement beneath structure would dictate rail elevation

Power Transmission lines Clearance between rail infrastructure and power lines required

EastLink Clearance above EastLink is required, in close proximity to the constraint provided by the power transmission lines

Approach to Stud Park Shopping Centre (Alignment A*)

1) Heritage building 2) Housing and social buildings – property acquisitions likely 3) Stud Road – track would need to be below ground 4) Topography – this means the station would be deep

East Link (Alignment C) Track level at grade, above Wellington Road, or diverted to the north or south, to avoid impact on major bridge and Monash Freeway Track level above road would avoid significant disruption to the existing road intersection (on and off ramps, existing traffic light changes and provision of U-turn for Wellington Road traffic)

Power transmission lines over Wellington Road

Use of cut-and-cover or bored tunnel, because ‘at-grade’ or viaduct would infringe clearance to power lines

Wellington Road Median east of Eastlink

A number of right turn lanes exist to the east of Eastlink, which coincide with the rail line’s below ground/above ground interface point

Rowville Main Drain beneath Wellington Road

Profile of the below ground track needs to be sufficiently deep to avoid affecting surface drainage

North side of Wellington Road from EastLink to Stud Road - little land width available also entrances to industrial area properties

South side of Wellington Road may offer a better corridor for open-cut alongside Wellington Road

Existing buildings on north west corner of Wellington/Stud Road intersection

Both options would require tunnel beneath buildings and therefore possible property acquisitions

Existing housing at Rowville on West Side of Stud Road bounded by Waradgery Drive and Lakeview Avenue

Forms a barrier to open-cut and viaduct construction

Stud Road – limited width The east side of Stud Road has a corridor of land that should be wide

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West to East

enough for open-cut or for diverted road carriage way. If not, viaduct construction would be the most economic solution, but is close to residential properties.

Existing utilities and services Other than the power transmission lines mentioned above there are no major existing utilities or services impacted by the rail alignment that would provide a significant constraint to the track alignment. See Appendix G for details of the major utilities identified.

Biggest physical opportunities along the track alignment from

West to East

Opportunity Implication for alignment

Width of median strip/width of North Road corridor

Open-cut track section can be used along the median in locations where there is no right turn lane reducing median width. It would require suitable barriers to separate the highway traffic and the railway (some at-grade overbridges would be required to maintain road system function from side roads). Cut and cover would be needed at right turn lane locations.

Strip of land on south edge of Wellington Road from EastLink to Stud Road (Wellington Road option)

Allows space for open-cut or viaduct track section for Alignment C into Rowville

Strip of land on east edge of Stud Road from Wellington Road to Stud Park shopping centre

Allows space for track for Alignment B* or C into Rowville

Strip of land between EastLink and Stud Road lying between the industrial area on the north side of Wellington Road and Kingston Links golf course

Allows space for an open-cut /at-grade relatively low cost / lowest cost entry to Rowville on Alignment B but restricted by unfavourable station location at Stamford Inn or Alignment B* with a more favourable station location at Stud Park shopping centre but requiring the demolition of significant quantity of residential properties near Stamford Inn.(this alignment option has not been taken further)

Undeveloped areas either side of Eastlink: Dandenong Valley Parklands South of Caribbean Lake

Allows space for an viaduct/at-grade /open-cut entry to Rowville on Alignment A and A* to a favoured station location at Stud Park shopping centre

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5. Alignment Options

Referring to the alignment plan drawings contained in Appendix H, it is useful to consider the alignment in three sections

West end Huntingdale Station connection

Central section along North Road and Wellington Road

East end at Rowville

In the central section the track alignment would be along the road median, or nearly so, with its position refined to reduce the impact on existing roads and services, and to optimise the location of new stations.

West end at Huntingdale Station connection options

A reduced service in the form of a shuttle service only between Rowville and Huntingdale opens up the possibility of a single track connection at Huntingdale. The options are:

a) Re-locate Huntingdale station northward towards Flinders St and provide an elevated track to Rowville curving on viaduct on the north side of North Road to a twin track viaduct along North Road

b) Provide an at-grade track southward under North Road flyover looping and climbing Eastward to a twin track viaduct along North Road

We have not taken this option further because it does not support the operational requirements of the rail link.

During the study process the likely service pattern of a frequent through service between Rowville and Flinders Street has been confirmed. The options are:

A. Piggy-back tracks at Huntingdale station with the Rowville tracks passing below ground southward under North Road flyover looping and climbing eastward to North Road

B. Relocate Huntingdale station northward towards Flinders St using piggy-back tracks with the Rowville tracks curving on viaduct on the north side of North Road to a twin track viaduct along North Road

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Central section along North Road and Wellington Road

Track would be located generally along the central median, either above or below ground depending on route topography and alignment constraints.

Where cut-and-cover tunnel is adopted the alignment may be best along the centre of one of the existing carriageways so that the other carriageway may be kept open during construction.

Where viaduct is adopted the alignment may be best along the centre of the median which minimises modifications and remedial work to the existing road.

East end at Rowville alignment options

The initial options for the approach to Rowville have been identified in Figure 1, described as A, A*, B, B* and C. As the study progressed, these options have been refined and named Golf Course North, Golf Course South and Wellington Road approaches.

Option A/A* (Golf Course North)

Option A entirely avoids existing buildings, and alignment A* provides a direct route to perhaps the most favourable station location for the future developed Rowville although residential property acquisition would be required.

Option B (Golf Course South)

It avoids existing buildings and provides a direct route without property acquisition to a station in the area of the Stamford Inn car-park.

Option B* (Golf Course South)

As B above except the track curves northward across residential housing and the Stamford Inn area to Stud Road and on to a station near the existing shopping centre. Residential property acquisition would be required.

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Option C (Wellington Road)

A similar concept to the heavy rail options in the Knox Report but with a simplified curve at the Wellington Road/Stud Road junction. This avoids residential property acquisition but some commercial property acquisition would be needed

Figure 1: East End at Rowville Alignment Options

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6. Alignment Option Selection

Alignment options and discussion

Rail Connection at Huntingdale An extract of the alignment drawing is below:

Option 1: Tracks on elevated structure and alignment is north of North Road (see

next sheet for layout plan at North Road) Characteristics:

Huntingdale station would be relocated in the up direction (towards Melbourne) to provide space for the curve into North Road. Track would be elevated on viaduct on the north side of North Road, and along North Road

Issues: requires the station to be relocated 200m further away from the

transport interchange requires property acquisition on north side of North Road long span required to clear North Road approach at skew noise and visual impact on local residents due to elevated position existing road intersections would be affected at the transition area

between the elevated track and below ground track Advantages:

likely lower cost than Option 2 which uses buried track

Option 2: Tracks below ground on alignment south of North Road Characteristics:

The Rowville tracks pass below ground southward under the North Road flyover looping and climbing Eastward to North Road

Issues: would need to avoid existing North Road flyover foundations (a

detailed investigation would be needed to quantify the impact) would significantly affect the Army Barracks and also the adjacent

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small single storey building (this could be avoided by a smaller radius curve with corresponding reduction in design speed to 65km/h

Advantages: Makes use of land area which in the most part is not built up retains the existing location of Huntingdale station which is well

suited for bus interchange Rail Connection at Huntingdale: conclusion

The preferred option is Option 2: tracks below ground on an alignment to the south of North Road. The tunnelling method would depend on availability of the Army barracks site for open excavations for cut and cover construction, which depends on agreements to be addressed as the scheme develops, and on the cost comparison between the different tunnelling types. Alternatively reducing the design speed of the railway to 65km/h at this location would mean the alignment could be adjusted to avoid the buildings. Section 7.1 describes the tunnel types in more detail. It would be worthwhile to investigate further during the next design stage the possibility of a shallow tunnel beneath the barracks without demolition (the Eastern Busway project in Brisbane accomplished a shallow tunnel with 5m cover and 10mm recorded settlement), this would require a detailed assessment of the ground conditions and acceptable settlement limits for the building. The major factor in this recommendation is moving Huntingdale station further away from the bus interchange (a requirement of Option 1) would reduce the interchange functionality, and additionally the elevated alignment would have a significant impact on road intersections along North Road. Station constructability considerations would suggest constructing the new platforms parallel to and off-line from the existing platforms, as described in more detail in Section 11 (Constructability).

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North Road (Huntingdale to Princes Highway)

An extract of the alignment drawing is below, from west (top) to east (bottom):

The North Road transport corridor has a varying width of 50-60m and comprises six

through traffic lanes, two bus lanes, an 18-20m median with cycle/foot path and relatively narrow verges. In order to limit traffic disruption during the construction stage, the median is the most suitable location for the railway, with the existing cycle/foot path moved to a re-modelled verge area. Option 1: Tracks on elevated structure

Characteristics:

the elevated structure would run along road median Issues:

the largely residential nature of the area would act against this option undulating ground would require the smoothed rail alignment to be

raised to provide clearance above high points on the ground and therefore significant structure height

noise and vibration issues associated with this structure type urban planning issues of a major elevated structure – scale and

height in residential area Advantages:

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would enable a shallow or ground level Monash University station better travel experience for rail passengers (natural light and views) likely to be lower cost than the below ground option

Option 2: Tracks below ground

Characteristics:

the railway would run below ground, most likely within the central median

Issues: costs for buried rail would be higher than elevated shallow tunnel may cause noise and vibration issues at the surface requires the Monash University station to be at significant depth

below ground level groundwater flows may be disrupted by the structure, requiring

diversion drainage services such as sewers crossing Wellington Road would need to be

intercepted and diverted Advantages:

lower urban planning impact than elevated structure

Option 3: Tracks at grade with shallow cuttings and embankments Characteristics:

the railway would be as close to ground level as possible, within the central median

Issues: unacceptable effects on existing road intersections would cause an ‘impermeable’ barrier along North Road preventing

pedestrians, vehicles and cyclists from crossing noise and vibration issues difficult to achieve without significant retaining walls due to ground

topography Advantages:

lower cost than alternatives

North Road: conclusion The preferred option is Option 2: tracks below ground. The alignment would be along the central median unless planning at detailed design stage indicated advantages of placing the tracks below one or more trafficked lanes, using cut and

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cover construction. The elevated structure and ‘at-grade’ track options would generate unacceptably high negative urban planning issues. Option 1: tracks on elevated structure, is not recommended, largely because the undulating ground would require the smoothed rail alignment to be raised to provide clearance above high points on the ground meaning significant structure height. The impact on local residences is considered too high. Additionally traversing the Princes Highway would require a significant engineering structure to span across the intersection without the addition of piers within the intersection area. The construction of tracks below ground could be by a number of methods, described generally as either ‘open cut structure’ or ‘buried structure’. The open cut structure would provide light and natural ventilation, but would require substantial traffic safety barriers which have a tendency to restrict the ability for road users to cross Wellington Road. Road crossing points could be provided by bridges to reduce the ‘barrier effect’. A buried structure could be provided by either a ‘cut and cover’ structure or driven/bored tunnelling methods. Section 7.1 describes the tunnel types in more detail. A major advantage of the cut and cover option is the shallower depth of the rail compared to a bored tunnel, therefore allowing a shallower Monash University station. The most cost effective method of construction would be the open cut and alternatively cut and cover, although the method of providing the buried structure could be reviewed at detailed design stage. However, management of the existing gravity drainage (surface water and sewage), other services, and also the groundwater flow, would need to be addressed. This is considered a manageable issue and would require interceptor and diversion works.

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Monash University Area An extract of the alignment drawing is below:

This area is on hill, which dictates a below ground station. With the railway approaching from Huntingdale below ground, the track profile to achieve clearance under the Princes Highway means that the station would be up to 18m deep to rail level. Approaching from Huntingdale on an elevated structure is not preferred for the reasons noted in the description for North Road in the previous section. The station construction could be undertaken by cut and cover method in line with the adjacent railway tunnel construction methodology.

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Monash University Area to the Monash Freeway

An extract of the alignment drawing is below, from west (top) to east (bottom):

The Wellington Road transport corridor is approximately 40m wide in this area and currently comprises six through traffic lanes, a median of approximately 7m width, a narrow verge and service road on the south side, and wide verge on the north side. The north side verge is a suitable opportunity for encroachment to provide for temporary or permanent traffic diversions, with the railway located along the central median. This road would cross Wellington Road, possibly at grade. The two proposals, although not coordinated, can work together if the road connection makes an ‘at-grade’ intersection with Wellington Road at a location beneath an elevated rail structure. Further work would be required on this during the next design stage. Option 1: Tracks on elevated structure

Characteristics:

the elevated structure would run along the road central median the gently undulating ground would allow the railway to follow the

contours without an excessively high structure the Mulgrave station would be on an elevated structure

Issues: partly residential nature of the area would act against this option noise and vibration issues associated with this structure type urban planning issues of a major elevated structure – scale and

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height in a residential area Advantages:

better travel experience for rail passengers (natural light and views) likely to be lower cost than the below ground option viaduct piers would fit within the existing central median therefore

avoiding the need for widening the road Option 2: Tracks below ground

Characteristics:

the railway would run below ground, most likely below the central median and two lanes of the existing road

Mulgrave station would be below ground and could be located closer to the residential catchment than for Option 1

Issues: requires the Monash University station to be lowered by a further 7-

10m than Option 1 costs for buried rail would be higher than elevated settlement issues at the surface affecting residential properties shallow sections of tunnel (cut and cover) would require services

diversions noise and vibration issues for shallow sections of tunnel

Advantages: lower urban planning impact than Option 1

Option 3: Tracks at grade with shallow cuttings and embankments

Characteristics:

the railway would run as close to ground level as possible, within a widened central median

Issues: effects on existing road intersections requirement for additional land or retaining walls would require services diversions

Advantages: lower cost than alternatives

The preferred option is Option 1: tracks on elevated structure. The relatively smooth

ground profile in this area is suited to allow a matching rail profile. The alignment would be along the central median, the north side verge is relatively close to properties, so is not the preferred location for the railway.

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Option 2: tracks below ground, is an alternative. This would be at additional capital cost but with reduced impact on the urban environment. The same design options for tracks below ground are available as described for the North Road section above.

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Monash Freeway to east of Waverley Park Station An extract of the alignment drawing is below, from west (top) to east (bottom):

The rail profile across the Monash Freeway is a continuation of the rail profile to the west, ie between Monash University and the Monash Freeway. The above ground railway shown for the section to the west allows the railway to be established on a structure at the same elevation as Wellington Road, as it crosses the Monash Freeway. It would be located between the two Wellington Road bridge structures. Should the below ground option be chosen for the area to the west (as described in the text above as an alternative option), then the Monash Freeway crossing would also be below ground, with the two rail profile options joining between the Monash Freeway and Waverley station. Waverley station would be below ground due to the steep ground profile immediately to the east of the station location. This ground profile is steeper than the maximum gradient that is achievable for new railway lines.

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Jacksons Road An extract of the alignment drawing is below:

The Wellington Road transport corridor is approximately 60m wide in this area and

currently comprises six through traffic lanes, a median of approximately 9m width, a narrow verge and service road on the south side, and wide verge on the north side. The north side verge would be suitable for the railway or alternatively for temporary or permanent traffic diversions. There are significant utility services in this verge. This is an important intersection for traffic turning right from Jacksons Road into Wellington Road and vice versa and, as noted in the plan extract above, would need to be closed to right turning traffic if an at-grade railway was located along the central median. There are two options for the alignment in this area: Option 1: tunnel portal and short length of ‘at-grade’ track in the north side verge

Characteristics:

tracks would cross below the east bound carriageways, with a tunnel portal at chainage 26400m, and a short section of ‘at-grade’ track leading to elevated structure at chainage 26600m. In order to maintain the Jacksons/Wellington road intersection, the railway would be located on the north side verge

Issues: the largely residential nature of the area may act against this option

because the ‘at-grade’ section of track and also the elevated structure to the east would be located closer to residences on the north side

utility diversions may be significant Advantages:

would limit the depth of Waverley Station compared to Option 2 better travel experience for rail passengers (natural light and views) likely to be lower cost that the below ground option

An alternative to Option 1 would be to use the central reserve instead of the north side verge, but this would necessitate closure of right turns at this road junction. Stakeholder feedback has indicated that this is not considered acceptable due to the traffic disruption associated with this alternative.

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Option 2: tracks below ground

Characteristics:

in order to maintain a rail alignment along the centre of Wellington Road and to protect the Jacksons Road intersection, the railway could be buried

It would require a below ground crossing of the Monash Freeway and therefore is linked to the decisions made for the railway profile from the Springvale Road crossing

Could tie-in to the rail profile on elevated structure to the east at approximate chainage 27000m

Issues: Would involve below ground track beyond the immediate area, at

least from Springvale Road to Jacksons Road and beyond - therefore capital costs for buried rail would be higher

would lower Waverley station compared to Option 1, from 15m to 29m below ground to rail level

would close the Gamett Road junction with Wellington Road unless the tunnel was sufficiently deep, which would lower Waverley station by a further 8m approximately

Advantages: Much lower urban planning impact of the railway line

Option 3: elevated structure over Jacksons Road

Characteristics:

the elevated structure to the east would be extended further west, over the Jacksons Road junction, towards Waverley station, therefore providing clearance above the Jacksons Road junction with Wellington Road

Issues: would require a significantly higher elevated structure to the east of

Jacksons Road (adjacent to residential properties) than Option 1 Advantages:

would not affect the road intersection

The preferred option is Option 1: tunnel portal and short length of ‘at-grade’ track in the north side verge. This has the advantage of balancing the depth of rail to the west at Waverley station and the height of elevated structure to the east. Services diversions associated with the rail alignment along the north side verge may be a considerable cost. The alternative of tracks below ground would lower Waverley Park station. An elevated structure over the junction would create a structure of approximately 17m (ground to rail level) further east as the ground falls away.

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Rowville Approach From approximately chainage 27000m, there are a number of options for the approach to Rowville and for the station location at Rowville. The following sections describe the three main alignment options, which are compared by the sketch in Figure 1 (page 11): (i) Alignment A/A* (Golf Course North) (ii) Alignment B/B* (Golf Course South) (iii) Alignment C (Wellington Road)

Option (i): Golf Course North Option An extract of the alignment drawing is below, from west (top) to east (bottom):

This option uses an elevated structure across the whole of the flood plain, east and

west of Eastlink, to address flood management concerns, and avoids the heritage homestead building to the west of Stud Road. The approach to Rowville would be under Stud Road to a deep station at Stud Park shopping centre.

Characteristics: elevated structure across the flood plain crosses beneath the power transmission lines crosses over Eastlink located close to a heritage listed building

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crosses beneath Stud Road terminates at a deep station beneath the Stud Road shopping

area Issues:

agreements with third parties needed (power transmission company Melbourne Water, Parks Victoria and private landowners)

requires residential property acquisition close to Stud Park requires substantial amendments to current plans for Caribbean

Business Park the station at Stud Park would be approximately 15m deep to

platforms environmental concerns associated with the wetlands and creek

habitats, and loss of open space

Advantages: straightforward rail profile with small number of constraints sidings would be located close to the station

An alternative to the buried structure approach to Stud Park would be to use an elevated structure over Stud Road. This would be up to 15m in height and would require acquisition of properties on the alignment and would significantly affect adjacent properties. The advantage of this option is that the Stud Park station would be within 4-5m of ground level rather than 15m deep.

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Option (ii): Golf Course South Option This option, shown in Figure 1 (page 11), has not been taken forward and detailed alignment drawings have not been progressed. This option is based on an elevated structure from chainage 27000 (where it leaves

Wellington Road) to a point just east of Eastlink. From then it drops into a buried structure until the termination point at Stud Park station. A significant number of properties would be affected by tunnelling in the vicinity of the Wellington road and Stud Road intersection. The constraint of the 500kV power lines as they currently exist would require the power lines to be raised. With the power lines raised, the elevated structure would continue further east over the Rowville Main Drain (due to gradient constraints the railway would probably not be able to dip underneath the drain) and into a tunnel portal in the vicinity of the housing near the Wellington Road/Stud Road intersection. This option has not been taken forward due to the effect on the residential properties and the need to raise the power lines.

Characteristics: elevated structure across the flood plain crosses over Eastlink crosses under power transmission lines buried structure east of Eastlink terminates at a deep station beneath the Stud Road shopping

area Issues:

considerable property acquisitions may be necessary along the route

flood levels make the rail profile difficult and would require the power transmission cables to be raised

flood risk to the tunnel (depending on chosen location of the tunnel portal)

agreements with third parties needed Advantages:

the station at Stud Park would be less deep than for the Golf Course North option

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Option (iii): Wellington Road Option An extract of the alignment drawing is below, from west (top) to east (bottom) and showing alternative locations for Rowville station:

This option follows Wellington and Stud roads. Moving eastwards, the rail crosses from

the north side verge, to the centre median of Wellington Road. It continues on elevated structure over the Wellington Road intersection with Eastlink, with an option to divert south past the intersection to limit structure height, and from then runs in a buried structure along Wellington Road and along Stud Road. Stud Road has an 8m median with an 18m reserve on the east side. There is also an option of crossing to the south verge and terminating at the corner of Wellington Road and Stud Road at ground level.

Characteristics: elevated structure over the Wellington Road/Eastlink intersection tunnel portal located approximately mid way between Eastlink and Stud

Road, tunnel from there to Stud Park shopping centre either runs along the Wellington Road median or south of Wellington

Road Issues:

the alignment across Eastlink creates undulating rail profile would affect right turns along Wellington Road existing median is narrow where the track would transition from above to

below ground – would require substantial lane adjustments The alignment needs to dip under the Rowville Main Drain at chainage

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29700m May require acquisition of the Stamford Inn property

Advantages: fewest property acquisitions required the station at Stud Park would be less deep than for the Golf Course

North option An alternative station location near the intersection of Wellington Road and Stud Road is possible based on an engineering assessment.

Approach to Rowville – options: Both Option (i): Golf Course North Option, and Option (iii): Wellington Road Option, are feasible. Option (ii): Golf Course South Option, is not preferred due to the issues noted above.

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7. Civil Structures Required

7.1 Introduction

The permissible maximum gradient of the track and the undulating ground levels would require various structural forms along the route. A further controlling requirement is that the route is to be grade separated at all intersections with track passing either under or over road infrastructure. This section describes the form of civil engineering construction along the track alignment.

The following is a step through the alignment to outline the basic structural needs. The structural types are discussed in detail in further sections of the report. The basic types are:

Open cut Cut and Cover Viaduct Sprayed Concrete Lined (SCL) Tunnel (Sequential Excavation Method) Bored Tunnel by Tunnel Boring Machine (TBM)

The alignment under discussion is shown on the drawings listed in Appendix H and adopts A* (see Figure 1) for the routing into Rowville. Subsequent sections of this report discuss the above structural types in more depth.

Huntingdale

The new underground platforms for Huntingdale station would be constructed in cut and cover in the area presently occupied by car parking and commercial property to the east of the existing Huntingdale station, or alternatively in a ‘piggyback’ formation beneath the existing platforms.

The down line would depart from the mainline in a decline structure passing into cut and cover and thence into the station box.

The up line would emerge from the station box in SCL tunnel in order to pass under the main lines and then pass into open cut to ascend to join the main up line.

This approach would allow the least disruption to the mainline as only the tie-ins would require rail occupation.

If the platforms can be located to the east of the existing station, the effect on the existing station would be small. It may be decided to refurbish the station to blend in with the new section however it is unlikely that this would disrupt the mainline any more than a conventional station refurbishment.

At the south end of the station the alignment would be required to negotiate the foundations of the North Road overbridge, North Road itself, Huntingdale Road and the Oakleigh Army

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Barracks. While cut and cover involving building demolition is an option, an SCL tunnel serviced from the station box would avoid these interfaces and depending on building foundation depth allow the barracks to remain.

The SCL tunnel would join cut and cover construction under the median of North Road at chainage 19100 having passed under the intersection leaving that intersection intact. The length of SCL tunnel from the Huntingdale Station box would be 750m.

North Road

The wide median in North Road allows structural form to be cut and cover. Safe maintenance of the cycle path presently routed long the median would be required. This might be achieved by temporarily combining with the side footways.

There are five crossing points through the median to service local roads. Although these could possibly be reduced in number those remaining would dictate the level of the railway.

The options are for the railway to be in cut and cover thus enabling the median to be restored as currently laid out or to have deep open cut with overbridges at the median crossing points. Open cut may have advantages in reducing the ventilation requirements but has the disadvantages of removing the median amenity and requiring safety measures in the form of crash barriers and high mesh fencing to avoid errant vehicles or their loads from reaching the railway. Right turns would be affected by an open cut structure and therefore cut and cover may need to be used at certain locations

Princes Highway Area

The intersection of Princes Highway with North Road (Wellington Road to the east) is a major and complex junction. It can be negotiated either in staged cut and cover construction or by SCL tunnel.

The location of Monash Station may have a bearing on the selection of construction type. If Monash station is located within the car parking zone of the university precinct then the alignment would have to pass from the median to the north side of Wellington Road and would therefore impact the east bound carriageway of Wellington Road. This station location would therefore favour the use of SCL tunnel not only to negotiate the Princes Highway junction but also cross the carriageway all without interruption to traffic. SCL tunnel might also better facilitate the separation of the tracks to allow an island platform at Monash.

Monash Station

Monash station as shown on the alignment plans would be constructed by cut and cover either under Wellington Road or biased towards the university precinct. Acceptable horizontal alignment and the location of buildings fronting Wellington Road at either end of the university parking area would dictate the station location.

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During construction the lost parking could be re-provided using temporary or permanent multistorey car parks.

Monash Station to Blackburn Road

From the east end of Monash Station the structural form would change from cut and cover or SCL tunnel if the latter is thought preferable to return to the Wellington Road median and close up the distance between the tracks if island platform configuration is used at Monash. The alignment would then emerge in a portal structure and after a short length at grade onto viaduct structure to pass over Blackburn Road.

Blackburn Road to Monash Freeway

The alignment would continue on twin track viaduct. An elevated Mulgrave Station would be constructed adjacent to Springvale Road. On the way to chainage 24850 the structure would lower to at grade either side of the Monash Freeway and pass over the freeway in the space provided between the existing Wellington Road overbridges. Construction would be similar viaduct throughout with no change in concept for crossing the freeway.

Monash Freeway to Jacksons Road

Here the scenario is similar to Monash station in that the Waverley Park Station would be constructed in cut and cover either under Wellington Road or biased to one side of it. Cut and cover or SCL tunnel would be used either side of the station before emerging into open cut. The construction of the station would involve fewer traffic plans and disruption to traffic if its foot print was removed from beneath the intersection of Wellington Road and Jells Road. Again SCL tunnel would have benefit in diverging the tracks if island platforms were used without disturbing additional widths of road corridor. Emerging from the sloping ground, the viaduct would need to be located in the north side verge, as described in section 6, to allow right turning vehicles at the Jacksons Road intersection. Any portal structure in the central median would need to take due regard of the lower elevation of the Wellington Road eastbound carriageway.

Jacksons Road to East Side of Flood Plain

Elevated structure would continue throughout this section to negotiate EastLink descending to at grade, embankment or elevated structure to ensure levels are sufficiently above the 100 year return flood level. At chainage 28600 overhead power lines cross the alignment causing a pinch point between the clearance to the powerlines and the required clearance to the traffic envelope on EastLink. The standard form of viaduct is unlikely to be suitable and a bridge of the ‘through truss’ type might be required.

Rowville

The tracks would be below ground under Stud Road, this would require the demolition of property (private dwellings) above the alignment. The section under Stud Road could be carried out in cut and cover or SCL tunnel may be considered to avoid disruption to Stud

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Road and the entrance to the shopping area. To descend earlier to maintain the properties would force the level of Rowville station to be overly deep with capital and operational cost penalties and the inconvenience to users of an unnecessarily deep station.

Bored Tunnel Alternative

All the sections noted above as cut and cover or SCL tunnel could be replaced with TBM bored tunnel.

Details of this method are explained in Section 7.8. It is unlikely that there would be any advantage in using TBM bored tunnel for the short section into Rowville station.

Having purchased the TBM for the project the alignment can be considered for additional lengths of tunnel especially if the sections of viaduct are considered to have to high environmental ‘cost’, such as the elevated section between Blackburn and Springvale Roads. Four of the five stations are already underground, this option would mean all five are. A tentative alignment is indicated by the red line on drawings SB19323-D-TC-002, 003, 004 and 005. The stations would all be of cut and cover construction. The revised alignment has used the 2% maximum vertical gradient of the original.

To assist this alternative alignment the Mulgrave Station adjacent Springvale Road would be located east of Springvale Road. Monash station would need to move as far west as possible towards Princes Highway to reduce its depth. Cut and cover or SCL would remain at Rowville due its short length and separation.

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7.2 Tunnel cross section requirements

Train Structural envelope, cant space The train structure gauge envelope is defined by the VRIOGS publication VRIOGS 0001-2005 Structural Gauge Envelopes – Minimum clearances for Infrastructure adjacent to the Railway

It appears that the likely tunnel sections would be on relatively straight track but it should be noted that any horizontal curvature would cause end and centre throws of the rolling stock which would have to be taken into account when developing the structural envelope from the kinematic. Cant of the track and whether the point of rotation is off the tunnel centreline would also have an influence on the tunnel cross section.

It is important that there is sufficient air space around the train for efficient ventilation. In a circular tunnel this is usually easily achieved.

The type of Overhead Line Equipment (OHLE) would dictate the overall height of the structural envelope. There are various types which would need to be assessed together with a decision whether to cater for an allowance for changing to high voltage (see section n9 for further details).

Emergency Walkway The minimum width of walkway would depend on the standard to be adopted. The US standard NFPA 130 requires a shaped space of minimum width 610mm at walking surface and at 2035mm height and 760mm at 1420 above the walking height. NFPA and Australian DDA regulations allow assistance in emergencies i.e. lifting off the train of wheel chair bound people. The level of the walkway should be such that it can be accessed from both the train and track level with the priority on ease of access from the train.

Service routing Services that would take up space within the tunnel cross section include.

1) Invert drainage 2) Pumping main from low point sumps 3) Fire main and associated valves 4) High Voltage cable ducting 5) Long line cabling for low voltage, signalling equipment and communications

equipment 6) OHLE

Track slab and derailment containment The difficulty of access to restore the train to the track and the destruction of railway equipment if the train departs significantly from its structural envelope has lead to the usual

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requirement of incorporating derailment containment in the form of a raised concrete plinth between the rails.

While most of the alignment is under existing highways the issue of noise and vibration may not require significant attention. However with recent developments of anti vibration devices, such as Pandrol Vipa pads, reducing vibration effects can be achieved in minimal space. There may be areas such as where the alignment passes close to hospitals, laboratories, teaching establishments or even residential areas where noise and vibration reduction may be considered necessary. It should be noted that the Melbourne Loop has a more bulky 1980’s version of an anti-vibration design.

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7.3 Cut-and-cover tunnel

The potential length of twin track cut and cover construction is approximately 3.7km.

Cut and cover construction has the benefit of using standard piling equipment that is readily available as similar techniques are used throughout Melbourne in basement construction. The design can easily be adapted to cope with variations in ground conditions above and below the watertable.

A typical cross section is shown in Figure 2. Piles are formed for ground support and in addition a central pile to assist roof support. The central pile can also allow the roof to be constructed in two halves to minimise space take up during construction and hence the impact on traffic.

Top down construction is envisaged whereby subsequent to piling the ground is excavated to soffit level, the roof constructed and the surface features reinstated. By keeping the level of the top of roof 1.5m below ground level there should be sufficient space for utilities to pass over. Special provision may be necessary for water utilities depending on invert levels. Provision can also be built into the roof to take the root ball of trees to be reinstated for reasons of amenity provided there is sufficient depth.

The walls can take the form of secant piles, contiguous piles or King post piles with arched shotcrete lagging depending on the ground support and resistance to water ingress.

The piling is taken below the base slab to ensure stability from lateral loading prior to completion of the base slab and also to provide resistance to hydraulic uplift in areas of high water table.

The method has the advantage that it can allow construction to start on as many fronts as necessary provided sufficient areas are available for handling the excavated material.

Alternatively long lengths of cut and cover can be constructed and excavation carried out from a single point by tunnelling methods under the protection of the roof and piled walls. This method is sometimes referred to as ‘Door Frame’ tunnelling.

A disadvantage of cut and cover is that long lengths of tunnel can form a barrier to natural groundwater flow especially if deep secant piling is used through permeably strata. This can cause settlement on the water depleted side and ground swelling on the side of water build up.

Although it is anticipated that most of the construction of cut and cover would be in the roadway median it is likely to require adjacent lanes and disrupt road intersections. It will be important to include the cost of traffic management into cost estimates.

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Figure 2: Cut and Cover Tunnel

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7.4 Open Cut

As the railway alignment passes from tunnel to at grade or viaduct there would be sections of open cut. The estimated length of open cut gives a total of approximately 1.5km. Generally these would take the form of similar walls to the cut and cover braced by a base slab.

Provision for a detraining and maintenance walkway on the outside of each track has been made.

If ground conditions allow support of the excavation using soil nailing techniques may be a possible solution. Near vertical and perhaps even vertical walls may be achievable with this technique, as shown schematically in Figure 4.

Soil nailing is an economical technique for stabilizing slopes and for constructing retaining walls from the top down. This ground reinforcement process uses steel tendons which are drilled and grouted into the soil to create a composite mass similar to a gravity wall with the tendons securing the potential slip zones to the stable areas beyond. A shotcrete facing is usually applied, though options such as precast panels incorporating architectural features can be used for the permanent wall facings. Figure 3 shows an example of a deep excavation supported by soil nailing, and Figure 5 shows the main features of a soil nail.

Figure 3: Example of Soil Nailing

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Figure 4: Open Cut

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Figure 5: Typical Soil Nail (From Ischebeck Titan Brochure)

Open cut railway next to road traffic would require special protection to prevent errant vehicles or their loads falling onto the railway. This is likely to require a substantial concrete safety barrier surmounted by a steel mesh security fence. For piled construction the safety barrier can be formed monolithic with the pile capping beam. For soil nailed walls the vehicle barrier has no pile to found on and hence it would need to be founded on competent ground at the excavation edge and tied back by ground anchors. An alternative to anchoring would be to attach the barrier to an RC slab under the traffic lane but this has the disadvantage of extending the width of construction.

The length of tunnelled railway would have repercussions for ventilation design and further design phases may reveal lengths of open cut to be an advantage over fully enclosed cut and cover. Where this occurs it is envisaged that the structure would be very similar to cut and cover with the roof replaced by a structural system of struts and walings to support the tops of the piles.

The negative side of such lengths of open cut is the loss of amenity of the road median and the visual intrusion of the traffic barriers and security fencing.

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7.5 Elevated Sections (Viaduct)

This section describes and discusses the possible options for the 2 elevated sections of the Rowville Rail Link. Viaduct construction is required for an approximate total of 5.8km.

Figure 6: Typical Viaduct

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7.5.1 Typical Design Elements

The typical design for an elevated railway involves a viaduct supported on piers. The viaduct would span over intersections and provide a fully grade separated route for the railway. It is a significant feature within the landscape and therefore careful architectural and urban design is required to positively mitigate the visual intrusion.

Superstructure Construction Recent Australian construction experience is that similar mainly highway viaducts are concrete box girders typically constructed from precast sections. In-situ concrete construction is not considered feasible due to the constrained nature of the alignment and the large amount of falsework required to support the weight of the wet concrete.

Steel superstructures are not recommended due to the capital cost of steel, the potential for increase noise and the high level of ongoing maintenance required. Additionally authorities are becoming less accepting of steel superstructures except in special circumstances due to the limited life of protective coatings. A steel superstructure would require repainting 2 to 3 times during its design life.

There are three possible superstructure forms appropriate for the viaduct with the design of the section driven by the chosen construction method. These are described as follows.

1 - Segmental Box Girder Construction A typical precast unit is 2.5 to 3m long. These are manufactured in a local site under controlled conditions so as to achieve a high quality finish and fit. The sections are then transported to site either by road or along the finished viaduct. The units are then glued into position and pre stressing cables are then used to stress the sections together to improve structural performance. The sections may vary in depth so as to achieve longer spans. Significant spans can be achieved with greater depths through the use of balanced cantilever construction. See Figure 7 and Figure 8.

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Figure 7: Typical Precast box girder segment

The precast segments would be prestressed together using high-tensile prestressing tendons. The tendons can either be internal or external. Internal tendons are inserted through ducts cast into the concrete and may be bonded (by grouting the ducts). This method is structurally more efficient and therefore would offer savings in material quantities. External prestressing is when the tendons are located outside of the concrete cross section, and within the hollow interior of the deck. This method provides easier access for installation and inspection. Normal practice would be to allow the designers to make the decision depending on the performance requirements, which may lead to a combination of both methods being adopted. A significant design parameter would be the preferred choice and availability of contractor’s plant.

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Figure 8: Segmental construction

Segmental Precast units may also be used in balanced cantilever bridge construction thereby achieving spans greater than 60m and so is suitable for use when crossing an intersection requiring good visibility at a junction, or over the EastLink (High Voltage lines permitting).

2 - Full Span Precast Box Girders For spans up to 40m an entire span may be prefabricated off site before being transported into position. This methodology has the advantage of minimizing the required work at height and is particularly suitable for construction through an urban area as the disruption due to the construction of the deck is minimized. Traffic along Wellington road could be maintained and the only requirement would be for a safety zone.

It is also possible to get very fast rates of construction, providing a huge benefit to the construction program. This method does require significant investment in a heavy duty launching gantry as shown in Figure 9.

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Figure 9: Full span erection on the Taiwan High speed rail

3 - Conventional girder deck bridge using super-tee girders 1800 deep super-tees can achieve spans for up to 30 metres for railway loadings. A likely deck arrangement would feature 4 super-tee girders per span supporting an in-situ concrete deck. No special construction plant is required with the girders erected using a conventional crane. Super-tees are the most common form of bridge superstructure in Australia and have been used on a large number of bridge projects.

The economies of scale associated with a project of this size dictate that a box girder structure, which is substantially more visually appealing superstructure, is likely to be similar in price to a super-tee superstructure. The use of super-tee girders would severely limit the scope for good seamless architecture. Additionally the span lengths would be limited to approximately 30 metres, requiring additional piers compared to a box girder. Super-tees are therefore not recommended for the main deck construction for this project.

Careful consideration of the articulation of the viaduct is required, in particular the location of the bridge expansion joints in relation to the rail expansion joints (if any). Determination of the articulation is somewhat dependent on the method of construction as each construction method lends itself to certain methods of articulation.

Sub-structure construction The purpose of the sub-structure is to support the viaduct deck. Piers are required to be robust against impact from errant vehicles yet slender to improve the aesthetics and reduce the cost. It is more effective to use single columns rather than two or more columns requiring a head stock structure. This form of construction naturally provides a good architectural

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opportunity. For each superstructure module (a module comprises a number of spans between expansion joints), torsional effects (particularly due to horizontal curvature), would need one twin bearing at each movement joint. The piers can be constructed either in-situ using formwork or can be constructed from precast segments stressed together. The form would be dependent on the construction contractor’s preference.

The foundations for the piers are typically piled using bored or CFA piles. The use of large diameter mono-piles for the foundations (subject to ground sub grade stiffness being adequate against lateral loading) would significantly increase the construction speed by reducing the number of piling operations and removing the need for a separately constructed pile cap. However this would require the use of specialized plant that may need to be sourced from overseas. See Figure 10.

Figure 10: Elegant piers founded on monopiles on the Palm Jumeirah monorail

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7.5.2 Elevated Station Design

The positioning of the station in relation to the local environment is a significant opportunity for high quality urban design. It is to be expected that the majority of passengers would seek to arrive at the station by foot and therefore the local environment should reflect the need for pedestrians to access the station from both sides of Wellington Road. The station precinct should also encourage onward travel by other sustainable means such as cycling.

A key operational aspect of the station that needs to be addressed in the structural design is the location of the ticket barrier and concourse. To minimize operational costs a single concourse is preferred, as well as providing increased security and safety.

There are two basic options for the layout of the station design:

Twin Platform design A twin platform design would allow the station to be constructed independently from the main viaduct construction. This would lead to efficiency in the construction as standardized precast deck units could be used continuously through the station.

A twin platform design requires a separate route for platform interchange. This may either be done at ground level, unlikely due to the presence of the road or via a dedicated structure either over or under the tracks.

The overbridge structure would require additional lifts and stairs to allow for access over the track as well as increasing the visual impact of the station. An alternative is for the passenger interchange to occur beneath the tracks - this space could also act as the main station concourse. The passenger interchange structure could also act as an open access grade separated crossing for pedestrians. See Figure 11.

Figure 11: Bangkok Skytrain station showing elevated pedestrian access routes under the tracks

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Island Platform Design

An island platform design is preferred from an operations and station design aspect. This allows for a single access point of entry to the platform and very easy cross platform interchange. Although the station footprint is reduced there is a need to split the tracks and therefore continuous construction of the deck is not possible. This would increase the cost of the viaducts as a non-standard deck section would be required. See Figure 12.

Figure 12: An island platform on the Singapore Mass transit system

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7.5.3 Approach Ramps and Tunnel Portals

There is a significant interface with the ground at each end of the viaduct and particularly where the route goes into a cut and cover section where a tunnel portal structure would be required. Each ramp offers a substantial challenge for urban and technical engineering design. The normal maximum operating gradient of 2% means that an embankment of over 100m in length would be required before achieving sufficient headroom for pedestrians. The embankment footprint is dictated by the type of material available and the form of construction. The embankments could be formed through recycling the spoil removed from the tunnels. Depending on structural properties of the spoil, the spoil may need to be treated or reinforced to reduce the footprint to an acceptable amount as against the footprint formed by its natural slope angle. The facing of the embankment would be a very important design feature; naturally graded embankments are often turfed though careful selection of species would be required to prevent desiccation. Alternative facings may be combined with geotechnical reinforcement to provide a combined sustainable and structural solution. Within an urban context a reinforced soil wall or steep embankment may be preferable, particularly where there are space constraints.

7.5.4 Trackform

The key issue that would need to be resolved over the full route is the choice of track form. Slab track is typically the preferred option due to its reduced whole life costs though careful design of resilient elements are required to ensure that the track form meets the required noise and vibration criteria. Ballasted track is the traditional form of permanent way and is cheaper initially but requires additional maintenance throughout its life to maintain performance. If there is surrounding structure to stabilize the track, as is the case on viaduct or in tunnel it is generally used to locate slab track and benefit from its longevity.

The design should eliminate or reduce the number of rail movement joints as these are high maintenance. A rail movement joint would be needed for structure expansion lengths of over 100m.

7.5.5 Design issues

The key benefits of an elevated viaduct are as follows:

An elevated viaduct is typically 30% of the cost of a tunnel. Elevating the railway does not sever adjacent communities Speed and ease of construction Safer construction Minimal impact on existing utilities (sewer, water, fibre optic) Good design would lead to the railway becoming a positive feature to the urban

landscape There is no disruption to the local ground water environment so no risk of settlement

impacts of adjacent buildings founded on soft ground due to tunnelling or changes in the water regime

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No requirements for additional specialised underground safety or communication systems as the existing systems can be used

The design would have to address the following key issues in order to achieve the benefits

Particular design effort is required to avoid detrimental visual impact There is a potential for increased noise impacts Construction activities may be extensive Maintenance activities need to be considered in the design Emergency responses requires careful planning Noise and Vibration These design issues are discussed in more detail below.

Adjacent communities The very nature of the elevated route enables existing links across the Wellington Road to be maintained in most cases. At each end of the viaduct, there would be an embankment and a cutting before the route continues underground. These features would act as a barrier and would need careful consideration in the design.

The substructures would need careful positioning to fit within the urban environment. There is potential for creating an unwelcoming, insecure and constrained area directly underneath the viaduct and therefore these areas need high quality urban design in mitigation.

Visual intrusion The design needs to account for the high level visual intrusion of the viaduct. There is significant opportunity for good architecture and urban design to mitigate against the visual intrusion and provide positive elements particularly around stations. Some key principles can be adopted to provide a consistent visual identity along the route and may include; support provided by single piers equally spaced and a continuous sections used throughout.

Traffic interface As the alignment of the elevated sections follows the median of Wellington road for the most part the only interface with traffic would be at junctions. Intersections should be accommodated within a single span though it may be necessary to increase the span locally or amend the intersection design to incorporate a pier. In such cases the piers should be positively protected for impact from errant vehicles. It is not expected that the controlling load case would be vehicle impact protection though local streetscape measures may be required to promote safety such as kerbs or protective barriers

The standard 5.4m headroom would be required across junctions though it is good design if this headroom is maintained along the entire length, and so not constrain any future intersections.

Noise and Vibration The passage of trains over the new railway viaduct would generate noise and vibration. Audible noise would occur at frequencies higher than those related to vibration, which are

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mostly inaudible. The magnitude of both noise and vibration would be predicted during the design phase and compared to acceptable ‘performance’ limits. A key consideration is that the alignment is in an already noisy urban environment and therefore a key design task is to establish the present ambient noise levels.

The measures which are available to mitigate excessive noise and vibration, are different. The types of special attenuation features would most-likely vary depending on the location; it is possible that some of the features discussed below would not be required – generally, or at all.

Mitigation of Noise The following measures each contribute towards the reduction of noise emissions from a railway viaduct. These measures focus on reducing high-frequency (audible) vibrations:

Sound Emitted as a Result of Wheel-to-Rail Contact

Ensure the condition of the rolling stock (particularly the roundness of the wheels), and the condition of the track rail, and track bed, are maintained to a high quality.

Use continuously-welded rail track. Use solid (and heavy) concrete noise barriers. These barriers may be incorporated into

the deck cross section, and are commonly used around the world for elevated railway viaducts, for the purposes of minimising rail noise, and also achieving an aesthetically-pleasing structure. Local up stands, positioned close to the rail provide the best noise mitigation as well as providing containment against derailment. They are not visually obtrusive as do not rise above car floor height.

Structure borne noise

Use spans of heavy material; use concrete spans instead of steel spans. Ensure non-structural viaduct components (e.g. services pipes, access walkways, sight

screens, etc), are resistant to loosening. Maximise the opportunities to dampen vibration within these components.

The relative merits of direct-fixation of rail track, versus the use of ballasted track bed, to limit noise and vibration would require an investigation to adopt the most suitable trackform for the rolling stock.

‘Resilient’ track fixings can be specified; these contain compressible components which reduce the vertical stiffness of the connection. These devices are useful in reducing structure-borne vibration/noise. There are a number of recognised systems incorporating resilient fixings that have been used on similar projects. It is important for maintenance that the same fixings are used for both the tunnel and bridge sections to maximise maintenance efficiencies

If ballast track is chosen then additional resilient elements such as a thick and continuous layer of elastomeric ‘ballast mat’ underneath the ballast would be provided.

If rail track is fixed directly to a concrete slab, this slab can be made to ‘float’ above the bridge structure in order to limit the generation of structure-borne noise and vibration. The

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‘floating slab’ is supported either by a thick and continuous elastomeric mat, or via steel helical springs (e.g. ‘GERB GSI-system’).

Mitigation of Vibration The following measures can each be expected to reduce vibration emissions from an elevated railway viaduct. These measures focus on reducing low-frequency (mostly inaudible) vibrations:

Use spans of heavy material; use concrete spans instead of steel. This measure lowers the frequencies at which the bridge vibrates.

Use longer bridge spans. This measure lowers the frequencies at which the bridge vibrates.

The relative merits of direct-fixation of rail track, versus the use of ballasted track bed, to limit noise and vibration would require an investigation to adopt the most suitable trackform for the rolling stock.

The choice of bearings for the viaduct is critical in reducing the transmission of vibration to the sub-structure. Elastomeric bearings tend to provide a natural damping effect, however are larger and may require a larger crosshead whereas pot bearings are usually better able to resist the large vertical and horizontal loadings associated with rail bridges and are more compact. However the bearing maintenance regime and the whole life costs associated with the bearings is important.

As an alternative to the use of elastomeric, or pot bearings, special high-capacity bearings with steel helical-springs could be used. It is most probable that these would be required only adjacent to buildings with extra-stringent requirements for mitigation and even then, only if vibrations are expected to be otherwise excessive.

The transmission of viaduct vibrations to adjacent structures is likely to be increased if there is some manner of direct, and rigid, connection between the foundations of each. For example it is sometimes possible that the vibrations generated by a structure which is piled to bedrock can be communicated to an adjacent structure which is supported similarly. The selection of appropriate foundation type for the rail viaduct should consider whether the foundation solution is likely to communicate unacceptable vibrations to adjacent structures – this may require the bridge viaduct design team to consult building owners to understand the nature of foundation support for adjacent buildings.

If the viaduct piers were founded, at select locations, on pad footings, it is likely that this foundation type would reduce the transmission of viaduct vibrations.

Performance Limits The prediction of vibration effects is a complex engineering challenge and would require specialist skills in the analysis and modeling of bridge dynamics. There are a large number of parameters which contribute towards noise and vibration which would need to be accurately identified and modeled. Analysis would be useful to understand the relative differences between alternative details as well as establishing appropriate performance limits.

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The bridge viaduct and rail components should be designed to satisfy legislated noise and vibration limits. In addition, the owners of building assets, which are located adjacent to the railway viaduct, should be consulted to determine whether any additional performance requirements exist; these should be included in the design requirements. An asset owner may claim a special set of performance requirements to limit noise or vibration and therefore a baseline study should be undertaken to determine the existing levels of noise and vibration caused by existing infrastructure, including roads. It would not be reasonable for the new railway viaduct to be designed to a set of conditions more stringent than those identified by the baseline study.

The main source of noise would be from the wheel rail interface. A well designed and maintained track would help minimize the potential for wheel noise and particularly flange squeal. The level of noise for low speed suburban trains is not expected to be significant when compared to the pre-existing road traffic noise, particularly in peak hours, however the alignment should avoid tight radius curves as this increases the risk of flange squeal developing as the track and rolling stock wears.

Access for Maintenance The viaduct would have to incorporate maintenance walkways on either side of the tracks to allow safe access to the permanent way during operation. The maintenance walkways can form part of the main structural deck section and perform a dual role by also acting as noise walls. As the track is elevated it is to be expected that maintenance plant would need to be track mounted. Some tasks such as bearing inspections and catenary maintenance may be undertaken from ground level using mobile elevated working platforms if required.

The internal dimensions of the box girder should allow for internal inspection, a minimum 1m internal depth is recommended.

Emergency Access and Evacuation In the event of an emergency that requires passengers to exit the train on an elevated section, procedures would be required to marshal the passengers safely to ground level. Typically this would involve stopping the trains and walking along the track to the nearest station or ground access point. As the elevated sections are less than 4km in length, unsightly intermediate emergency access staircases need not be required. It is reasonable to expect disembarked passengers to walk up to 2km to an evacuation point.

7.5.6 Construction Issues

Foundations A full geotechnical investigation is required with core holes taken at designed pier positions to confirm geology. The construction of a single monopile greatly reduces the disruption on site and would lead to significant cost savings over other solutions if geotechnical conditions permit it.

Services and Utilities Services would need to need to be identified early and if necessary diverted.

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Location of casting yard The location of the site compound and casting yard is critical. A site should be chosen to be close to the construction site to allow for the greatest efficiency in moving the precast units from the “factory” to the site. Full span precast units would be very heavy and therefore routes to the site may need investigation and possible strengthening of culverts and bridges. If full span units are to be used it is normal to locate the casting yard directly adjacent to the structure to minimize the number of lifts and lifting equipment. A casting yard would be equipped with a purpose built gantry to lift the units on to the viaduct and where a purpose built tractor would be used to move the units using the partially completed viaduct as the haul road. Using the viaduct as the main access road for construction would minimize the disruption for local traffic. See Figure 13.

Figure 13: Full span precast units being moved on the Taiwan High Speed Rail Link

A significant issue for the construction is that viaduct is possible for two separate sections of the alignment. Detailed construction planning would need to be undertaken to establish the staging of the construction and plant utilisation.

Working close to live traffic. The construction method may have significant impacts on the local traffic; this would need full investigation as part of the construction and traffic planning as part of further work.

Erection of Precast units There are two main methods by which the pre-cast units may be erected:

Crane Erection Individual precast segments can be erected via the balanced cantilever constructed method slowly working out from a pier in a balanced manner. Each individual segment is temporarily stressed to the previous unit, prior to final prestressing once a full span is erect. The advantage of this method is that a purpose built gantry is not required with only conventional

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cranes being required. This has programming advantages in that the work can progress at several sites concurrently.

Travelling Gantry- Under or Overslung A purpose build erection truss supported either by temporary or permanent piers on which a spans worth of precast sections is installed prior to being stressed into position. This system is tried and tested throughout the world, and has recently been employed in Australia on projects such as Adelaide’s South Road Superway, Brisbane's Gateway, Sydney's M7 and Melbourne's Western Link. This method of construction allows the majority of superstructure erection to be undertaken at height, with minimal disruption to traffic and other activities on the ground. Spans range from approximately 40m to 60m. See Figure 14 and Figure 15.

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Figure 14: Underslung gantry during construction of Sydney’s M7 orbital

Figure 15: Overslung travelling gantry constructing in Delhi

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7.6 Bridges

7.6.1 Princes Highway grade separation

A bridge crossing the Princes Highway would be applicable if viaduct is used for the alignment along North Road. Its form would be as per the standard viaduct construction to be adopted.

7.6.2 Monash Freeway grade separation

The existing Wellington Road crosses the Monash Freeway on a 4-span reinforced concrete bridge. A rail overbridge could use a similar span and column arrangement as the road bridge with the track at a similar level to the existing road or viaduct construction could continue through.

7.6.3 East Link grade separation, Alignment A or A*

As noted earlier these alignments require the crossing of EastLink adjacent to the overhead power lines. If space does not permit the viaduct form of bridge construction through truss bridge design may be required to limit overall depth.

7.6.4 East Link grade separation, Alignment C

The existing Wellington Road crosses EastLink on a 2-span reinforced concrete bridge. A rail crossing could use the same span and column arrangement as the road bridge with the track at a similar level to the existing road (with a change in the road traffic signals and U-turn provision) or, in an elevated position, to allow traffic to use the existing on-off road ramps on the North side of Wellington Road. Alternatively, as shown on the alignment drawings, the rail could divert to the north or south.

The rail bridge could be steel beams with a reinforced concrete deck or precast concrete beam and deck construction.

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7.7 Sprayed Concrete Lined Tunnel

There are locations along the rail route where it may be desirable to use shallow cover driven Sprayed Concrete Lined (SCL) tunnelling techniques or to use these methods because other methods such as cut and cover tunnelling are not feasibly at a particular location.

Likely locations for shallow cover driven tunnels are as follows:

The mainline railway connection at Huntingdale Station. Under major road intersections (e.g. Princes Highway). Under buildings and Stud Road on the approach to Rowville.

In some situations a driven tunnel may be more desirable along some length of the alignment because of environmental noise factors associated with say the cut and cover method during the construction phase.

While details at specific locations are not known at this level of study it is possible to predict that shallow cover driven tunnel methods could be used at any location along route. The only variables significantly impacting the construction time and cost are the geological profile at each location and the length of tunnel to be constructed. The range of tunnel techniques available means that for all practical purposes on any site shallow tunnelling would always be feasible.

A generic form of shallow cover tunnelling for short tunnels (say under 1 km in length where a Tunnel Boring Machine or Shield would be considered too expensive or not practical) is the canopy tube method with shotcrete and steel lattice girder tunnel support over the arch. The face of the tunnel can be stabilised during construction by excavation staging using heading and benching, fibre glass, spiling/face nails or shotcrete or any combination of the these methods. The steel canopy tubes are installed ahead of the tunnel in an array over the tunnel arch and this process is repeated as the tunnel excavation advances. The steel tubes being 12m in length with a 3m overlap between successive arrays. The final tunnel lining can be the initial shotcrete support over the tunnel arch or range up to a steel reinforced in-situ concrete lining.

Generally as a minimum for rail tunnels it is desirable to prevent drips from the tunnel crown and to manage potential ground water flows. The selection of tunnel waterproofing today ranges from a spray-on waterproofing membranes (used over shotcrete lined tunnels) to sheet membranes (used in tunnels with an in-situ concrete lining). The tunnel does not necessarily have to be watertight with the tunnel invert perhaps being drained.

The potential geological conditions vary significantly according to the desktop study carried out to date. The near surface layers consist of silts, sands, clays and some gravels. Near

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Dandenong Creek the water table is near the surface, elsewhere the watertable is 5m to 10m below the surface.

From the surface the next layer of strata is likely to be the over-consolidated clays, sandy clays and clayey sands of the Brighton Group.

Under the Brighton Group there will be mostly weathered Siltstone and Sandstone – typically low to medium strength. That is rock in strength ranging from around 3MPa to 20MPa unconfined compressive strength. This rock formation is highly folded with anti-clines and synclines which in an open face tunnel excavation would require careful monitoring. In extreme cases tunnel face support can be provided by fibre glass face spiling/nails and shotcrete.

With the method of construction discussed and even with shallow ground cover, surface settlement would be maintained below acceptable limits. This point is particularly relevant for the tunnel under the existing railway line at Huntingdale station required to make the connection to the Rowville line. Recent work in Brisbane with a completed shallow tunnel and also in Sydney for a detailed rail underpass study currently in progress to traverse below three active railway lines we can be confident that little if any disruption to the railway network would occur. At Huntingdale Station there may well be some initial track possessions for construction of the dive structure before tunnelling under the tracks can either commence or be completed.

Figure 16, Figure 17 and Figure 18 below are of previous successful SCL shallow cover tunnel projects.

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Figure 16: Buranda Brisbane, Ground cover under rail tracks 3m

Figure 17: Pipe arch and steel sets (Source Boggo Road Busway Brisbane)

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Figure 18: Cross section of Boggo Road Busway, Brisbane

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7.8 TBM Bored tunnel

7.8.1 General Principles

The tunnel is created using a TBM and its back up train. A circular tunnel is created due to the rotating cutter head. The TBM is driven forward by jacking off the previously installed linings or gripping the tunnel walls or a combination of both. Double shell TBMs allow the excavation to occur independently of lining erection and can speed up the drive.

As noted in the geotechnical section of this report the geology of the area is of mixed ground with Quatenary and Tertiary sands clays and gravels and also lower Devonian siltstone and sandstone. The siltstone and sandstone are reported to be mainly weathered and of low to medium strength but higher strengths may be encountered. Groundwater level is noted to be in the range of 5 to 10m below ground level. A closed face TBM is therefore required which would pressurise the face to support it during excavation and prevent water inflows. The two types are:

Earth pressure Balance (EPB) TBM – Pressure is applied to the face by the extraction of excavated material through a screw conveyor. The excavated material can be conditioned by the addition of additives to create a cohesive material to combat the situation when water bearing sands and silts are met. The machine is ideal for clays, silts and sands and can also cut rock but grinding the rock to the particle size for transport through the screw conveyor can often cause excessive wear on the cutter head. Bands of ‘Iron Stone’ in the Brighton Group present a risk in this regard. The TBM can be designed to allow removal of the screw conveyor so that progress can be made in ‘open’ mode if ground conditions permit, allowing removal of larger rock fragments by conventional conveyor. Such changes should be limited, however due to the effect on the construction programme.

Slurry TBM – This pressurises the tunnel face with bentonite slurry which is also used to export the excavated material from the tunnel. A treatment plant, outside the tunnel, is used to extract the excavated material and return the bentonite to the face. This machine can deal with rock more easily as it does not have to grind it to small particles. However control of pressure can be an issue at shallow depths with the risk of disturbance of the soils above and even blow out to the surface. The treatment plant is an expensive addition to the process.

While the decision as to which machine is suitable for this project would be the subject of further study, assuming that it is an EPB the alignment should have places of access to the cutter head for maintenance and change of cutters at approximately 500m intervals. These can be at convenient shafts or specifically formed intermediate blocks of treated ground. Alternatively a contractor may choose compressed air for ground stability during cutter maintenance. TBMs can bore any length of tunnel but their high initial cost lowers their cost effectiveness for shorter distances.

Segmental concrete linings are installed by robot erectors in the tail skin at the back of the TBM ‘shield’. The completed tunnel then emerges from the back of the shield as the shield

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progresses forwards. There is a slight overbreak made by the cutter above the shield diameter to allow ease of passage and directional change. An addition to this annulus is created by the thickness of the shield. As the lining leaves the shield the annulus is immediately pressure grouted to seal the void and prevent the ground closing

Segments are commonly 1.5m wide, 300mm thick with 6 to 8 segments forming each ring. Waterproofing is provided by ‘rubber’ gaskets abutting in the joints between the segments. The gaskets are tested to ensure they can cope with the misalignment tolerance envisaged. The segments are bolted together to initially compress the gaskets and aid erection.

Minor leakage may occur below the water table in non-cohesive soils, however this can often be reduced or eliminated by back grouting.

A typical segmental lining ring is shown in Figure 19.

Figure 19: Principle of precast segmental lining (Note: ignore dimensions. Cross joints would be

staggered by alternate ring rotation)

A tunnel diameter is the usual desired cover above TBM segmentally lined tunnels. Ground cover of less than a diameter can be achieved though, in soft ground, this usually requires ground improvement over the tunnel depth and is usually limited to the tunnel portal areas.

Wedged key

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It is desirable to limit the influence of a second bore on the first by having a separation of 2 to 3 x diameter centre to centre.

7.8.2 Twin tunnels versus single bore

Cross section, Dividing wall For the purposes of fire and life safety and ventilation it would be necessary to construct a separating wall along the centreline of a twin track single bore tunnel. The walkways would be located either side of the central wall with means of escape through fire doors to the non incident track. Sydney’s recent Airport Link is a notable exception to this requirement.

Effect at stations and portals Island platforms are generally considered preferable for station design however the twin track single bore configuration is not compatible with island platform stations. The larger diameter of the single bore may cause the stations and portal structures to be deeper.

Ground settlement issues The settlement effects of a single bore would be more in terms of face loss (ground loss as a percentage of excavation) due to the increased cross sectional area. However it would be more concentrated. If the alignment is generally following a road then buildings either side may be more onerously effected by the wider twin bore configuration. However if settlements were likely to be an issue the tunnel separation can be reduced so that there is one metre between the tunnel extrados if an Earth Pressure Balance (EPB) type of Tunnel Boring Machine (TBM) was to be used. Adequate control of EPB pressures in soft ground would be required.

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Qualitative comparison

See Table 1 below for approximate dimensional comparison

Dimension Twin Bore Single Bore % increase of Single over twin bore

Internal Diameter 6.2m 11.0m

Lining thickness 300mm 450mm

Volume of concrete/m 6 x 2 = 12m3 Lining = 16m3

Central Wall

8 x 0.3 = 2.4m3

Total 18.4m3

53%

Excavated diameter assuming 150mm annulus for TBM shield and grouting

7.1m 12.2

Excavated volume /m 39.6 x 2 = 79.2m3 117.0m3 48%

Table 1: Twin versus Single Bore approximate dimensional comparison

The additional cost for the volumes of concrete and excavated material of the single bore would be part compensated for by the need for cross passages between the twin bores. If NFPA 130 is adopted these would be required at 244m spacing between the stations.

There is likely to be little difference between the supply cost of two Tunnel Boring Machines (TBMs) for the twin bore and one much larger TBM for the single bore.

The increased depth from tunnel crown to the track of a single bore may increase the cost of stations and decline structures.

Sustainability The additional quantities of excavated material and concrete for the single bore would make this option much more resource and energy absorbing and have a much increased carbon output.

Conclusion on twin tunnels versus single bore. Due to increased cost, effect on station layout and less sustainability of the single bore when compared with the twin bore it is recommended that bored tunnelled solutions adopt twin tunnels.

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7.9 Station design

7.9.1 Underground Stations

Layout Underground stations can take many forms but can be summarised as:

1) Cut and Cover box such as Melbourne Central on MURL (Melbourne Underground railway Loop). Most favoured architecturally due to increased amenity, spaciousness and often a chance for daylight to penetrate into the depths of the station.

7) Cavern such as on the Epping to Chatswood line in Sydney. Suitable at relatively deep depths and where ground conditions are good such as competent rock

8) Tunnelled with platforms in separate tunnels such as a majority of the deep London Underground and Parliament Station on the MURL. Least favoured due to the reduced amenity and lack of openness.

Deep stations are to be avoided, if possible, due to cost and increased vertical circulation which increases operational costs and passenger time.

Guide dimensions for station depth are given in Table 2.

Dimension m Comment

Road level to top of roof slab 1.5 To allow for utility reticulation

Roof slab structural depth 1.5

Concourse height 4.5 Includes allowance for false ceiling

Concourse floor structure 1.0

Track to soffit 5.4

Total, Track level to ground level

13.9 Commensurate with TBM bored tunnel depths

Table 2: Guide dimensions for station depth

A significant feature of station design is whether an island platform (between the two tracks) is used or side platforms. It is usually perceived that the island platform is preferable for the following reasons:

For am/pm tidal flow passengers can be less crowded as the adjacent platform can be used for over spill.

The normal vertical circulation can be shared. (Emergency evacuation requirements, catering for both platforms to be simultaneously evacuated, tend not to give island platforms an advantage.)

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While twin single track TBM bored tunnels are easily compatible with an island platform twin track single bore configuration either in SCL tunnel or cut and cover are less so as they would need to bifurcate either side of the station.

Structure Station construction for the feasibility alignment discussed in this report would be cut and cover dictated by their depth and ground conditions.

The walls would be constructed in a similar way to the cut and cover sections by secant, contiguous or king post piles. A further option that could be considered is diaphragm walls especially if the station is located in water bearing non cohesive ground. The walls would be braced by the various floor levels and the roof. Flotation would be resisted by pile or wall embedment. Embedment in a low permeability medium would seal against water ingress. Generally with an island platform support to the floors can also be provided along the platform centre line.

If the stations are located under roads they can be constructed under temporary decking or the roof slab constructed in two halves in order to reduce the effects on traffic flows.

7.9.2 Elevated Stations

See section on viaducts for discussion of elevated stations.

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7.10 Fire and Life Safety

7.10.1 Fire Engineering Process

The fire & life safety design of sub-surface rail infrastructure projects in Australia is generally guided by the process specified by AS4825-2011 and detailed in the International Fire Engineering Guidelines (IFEG). This process specifies development of a Fire Engineering Brief (FEB), which specifies the objectives, fire safety measures, analysis methods and acceptance criteria. This document gains approval via consultation with the relevant stakeholders, which assures an acceptable fire safety design. A second document, the Fire Engineering Report (FER), details the fire safety provisions of the actual design.

The relevant stakeholders in this process include:

End User Authority Having Jurisdiction Train Operator Rail Network Manager

7.10.2 Applicable Legislation & Standards

The principal applicable legislation and standards are:

Rail Safety Act 2008 BCA 2011 Building Code of Australia VRIOGS 002.1 Rev A 2011 Railway Station Design Standard and Guidelines AS 4825-2011 Tunnel fire safety AS 1668.1-1998 The use of ventilation and air conditioning - Fire and smoke control in

multi-compartment buildings AS 1668.2-2002 The use of ventilation and air conditioning in buildings - Ventilation

design for indoor air contaminant control SRA Guidelines Section D Railway Tunnel Services

For fire safety, the standards listed above are underpinned or supported by other guidance and standards including:

International Fire Engineering Guidelines USA’s National Fire Protection Association (NFPA) 130 Standard for Fixed Guideway

Transit and Passenger Rail Systems, 2010 NFPA 92B Standard for Smoke Management Systems in Malls, Atria and Large Spaces,

2009 SFPE Handbook of Fire Protection Engineering, Society of Fire Protection Engineers

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The primary standard for the tunnels is AS 4825.

The stations would be required to comply with VRIOGS 002.1. The primary referenced standard for the station platforms is NFPA 130. For the stations above platform level, BCA applies. BCA is assumed not to apply to the station platforms as they are extensions of the tunnels.

Due to the difficulty of demonstrating compliance with the Deemed-to-Satisfy (DTS) provisions of the BCA in underground stations, a full performance-based design is recommended as per the provisions in VRIOGS 002.1. The performance requirements of the BCA should be used for the station design above platform level and NFPA 130 for the platform designs in order to demonstrate acceptable levels of life safety.

7.10.3 Principal Characteristics

Tunnels & Underground Stations The project plans to include a number of tunnels and underground stations.

The tunnels would either be TBM bored SCL mined) or cut-and-cover. If a tunnel is bored it would be twin-bore, single-track type. If a tunnel is SCL or cut-and-cover it would be double-track, with a solid dividing wall constructed between the two tracks to provide separation. Both methods comply with AS 4825-2011. If the tunnels are longer than 250m, they would need to be treated as Long Tunnels under the provisions of AS 4825-2011.

It is envisaged that all sub-surface stations would be of the island-platform type, regardless of the method of tunnel construction.

At this stage in the process, the design of stations may be covered or open. If covered, even with just a canopy, they would be classified as sub-surface stations and the provisions of NFPA 130-2010 would need to be taken into account.

Traffic The rail line would carry heavy-rail suburban passenger traffic. Initial traffic levels are envisaged to be 3 trains per hour (TPH), rising to 6 TPH following subsequent improvements to the mainline.

Occupants Load - The passenger occupant peak loading per train would be rolling stock dependent. However typical load profiles follow a fairly standard pattern, with peak loadings experienced during the AM rush period, and a lower peak occurring during the PM rush period.

Language - It is expected that all passengers would be able to understand signs and verbal instructions in English, even if it is not their first language.

Awareness - It is expected that all passengers a, be awake and alert, however some may be under the influence of alcohol, depending on the time of day (e.g. evenings and weekends).

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Mobility - It is expected that most passengers are fully mobile, however a proportion would be Persons of Restricted Mobility (PRM) for which special provision must be made. The normal statistical distribution for mobility for the average Australian population is that 5% of the passengers may have some mobility restriction and qualify as PRMs, while less than 1% are expected to be using mobility aids such as wheelchairs, crutches, walking sticks, etc.

Other occupants would be drivers and guards, who are expected to be fully trained and mobile, and fluent in English.

7.10.4 Fire Safety Objectives

The main fire safety objectives of the project are to:

Achieve compliance with legislation and standards Ensure life safety of the public, railway staff and the emergency services Ensure service continuity and asset protection for the infrastructure Provide suitable means of access for the fire brigade

7.10.5 Fire Hazards & Risks

Frequency of Fires The likelihood of serious fire incidents in the tunnels is extremely low. The risk of a fire incident is influenced by a number of factors including the characteristics of the tunnel (such as its length), the frequency and type of the train traffic and operations.

The tunnels would be twin-bore, single track and with uni-directional traffic in each bore, so risk of collision is low.

Typical train fire causes arise from various defects within the train equipment such as electrical faults, overheating of brakes, flammable liquid leakages. These typically result in under-car fires on passenger trains. Another common cause of fire on passenger trains is arson and/or vandalism. These typically result in in-car fires on passenger trains.

The UK Railway Safety and Standards Board (RSSB) carried out an extensive statistical analysis of the causes of train fires over the period 1992-2000 ("Train Fires - Special Topic Report", January, 2001). The data showed that 44% of all train fires and 56% of passenger train fires were arson-related. For Electric Multiple Units (EMUs) the percentage was even higher: 75% of fires on EMUs were arson-related. Technical causes accounted for 39% of all train and rail vehicle fires. Non-EMU types accounted for 77% of the technical-cause fires over the period studied.

Arson and vandalism incidents typically occur on trains with a low passenger load. Conversely, the risk to life safety is highest on trains with a high passenger load. The RSSB report data revealed a very low incidence of casualties from fire incidents over the period studied, as most of the fires were of a non-serious nature.

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The RSSB 2001 "Special Topic Report" cited above also found that the risk of fire from train faults is generally higher for diesel and diesel-electric traction-powered types of rolling stock than for the electrical traction-powered rolling stock which would be most likely for Rowville.

At this stage, the specific rolling stock that would use the line is not defined. However, it is likely to be suburban passenger EMU-type rolling stock, currently envisaged to be 1500V DC. Should DMUs or other rolling stock types be envisaged, it would alter the fire safety risks.

It is assumed at this stage that all rolling stock would have side detrainment facilities.

7.10.6 Concept Requirements -Tunnels

The exact number and length of the tunnels is yet to be finalised, however the provisions of AS4825 and NFPA 130-2010 need to be taken into account in the concept stage of tunnel design.

Likewise, the exact number of sub-surface stations is yet to be finalised, however the provisions of BCA 2009 and NFPA 130-2010 need to be taken into account in the concept stage of station design.

Some basic operational assumptions are as follows:

In event of fire occurring on a train in a tunnel, the train will proceed to the next available station if at all possible prior to detraining.

If detrainment between stations becomes necessary, persons will evacuate onto a side walkway and be directed via wayfinding signage to the nearest suitable exit from the tunnel.

In this event, the tunnel ventilation system will be employed to maintain a tenable environment for the duration of the evacuation.

If detrainment occurs at a station, persons will evacuate through the station's egress routes to a point of safety at ground level.

In this event, the smoke control systems provided at the station will be employed to maintain a tenable environment for the duration of the evacuation

Specific requirements that would influence the tunnel concept include:

Fire Load - This would be rolling stock dependent, however based on current rolling stock types in service, a fire size of 20MW should be sufficient for safeguarding at this stage. This value can be reviewed as the project progresses and more information becomes available.

Egress - Evacuation requirements would drive a number of high-level design parameters:

In the tunnels a side walkway would be required, the minimum dimensions of which are specified in NFPA 130-2010, Clause 6.2.1.9.

Provision must be made for evacuation via the portals as well. At each place of safety on the surface, provision must be made for safe dispersal of the

evacuating persons.

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Maximum permissible distance between tunnel exits is 240m (AS 4825-2011, Table 7.1, Clause 8(a) - NFPA130 states 244m between cross-passages, 762m between exits to surface) - these may be cross-passages to the adjacent bore, or exits to surface. It is recommended that cross-passages be provided on a 240m maximum spacing, with exits to surface provided at no greater than 762m spacing. However the provision of cross passages is expensive and value engineering together with fire engineering may be able to increase these distances during detailed design

Smoke control is required in the tunnels. The exact type of smoke control system employed would be dependent on tunnel length, amongst other factors. The smoke control system needs to provide tenable conditions along the evacuation routes for the duration of the evacuation. It is also desirable for it to provide a relatively smoke-free intervention route for the emergency services, particularly fire-fighters.

Any intermediate shafts that provide evacuation facilities would require pressurised stairs.

Emergency lighting and illuminated wayfinding must be provided.

Intervention, Fire-Fighting and Passive Provision

Hydrants must be provided at portals. A fire main with hydrants must be provided along the length of the tunnel. The fire-fighting water supply must be provided with a redundant supply and booster

facility. Provision must be made for emergency vehicles at all intervention points. Structural fire resistance must meet provisions of Table 4.4 in AS 4825-2011.

7.10.7 Concept Requirements - Stations

Assuming the stations are covered and thus defined as sub-surface, specific requirements that would influence the stations' concepts include:

Fire Load - This would be rolling stock dependent, however based on current rolling stock types in service, a fire size of 20MW peak HRR, for a train on fire at a platform scenario, should be sufficient for safeguarding at this stage. This value can be reviewed as the project progresses and more information becomes available. For other types of fire scenarios, typically "small" fire scenarios such as luggage fires, a fire size of 1MW peak HRR should be sufficient for safeguarding at this stage. This also can be reviewed as the project progresses and more information becomes available.

Egress - Evacuation requirements would drive a number of high-level design parameters and must satisfy the requirements of NFPA 130:

Maximum travel distance on the platform to an egress route not to exceed 100m; Capacity to evacuate the platform in not more than 4 minutes; Capacity to evacuate from the platform to a point of safety in not more than 6 minutes;

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Smoke control systems that provide tenable evacuation conditions may allow these evacuation times to be modified, following engineering analysis;

Evacuation stairs (and elevators if used) and their associated lobbies shall be fire-protected and pressurised;

Emergency lighting shall be provided; A means of emergency communication must be provided. Intervention, Fire-Fighting and Passive Provision

Fire-fighting lifts and stairs must be provided. These need to be fire-protected and pressurised;

A source of fire-fighting water should be provided on the platforms, via fire-mains and standpipes or hydrants.

Structural fire resistance must meet the provisions of BCA and NFPA 130.

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7.11 Ventilation Concepts

7.11.1 Tunnel Ventilation System

The purpose of the Tunnel Ventilation System (TVS) is to:

Maintain conditions for the comfort of passengers and personnel during normal and congested operations, and

Provide conditions for the safe evacuation of passengers and personnel, and tenable conditions for the intervention of the emergency crews, in the event of an incident.

During normal operations the TVS maintains air temperatures in the running tunnels and in the public areas of the underground stations to support the comfort of the passengers and personnel.

Where twin bore, single–track tunnels are used, it is generally possible to ventilate them passively by using the movement of the trains to exchange the air to atmosphere through draught relief shafts generally located before entry into a station.

7.11.2 Station Ventilation

A large part of the train related heat is rejected during the dwell periods at the station, and the ventilation strategy should be designed to capture this heat before it enters the public areas. This can be achieved by using Under Platform Extract (UPE) to capture the underframe heat gains, and possibly Over Track Extract (OTE) to capture the heat from the condensers of roof mounted air-conditioning units. The UPE and OTE make up the Track Extract System (TES).

Most of the underframe heat comes from the brake resistors, and the UPE should be seen only as a part of the overall energy strategy for energy management. The regeneration of braking energy can both improve heat management, and reduce the overall consumption of traction energy. The purpose of the TES is to capture, as far as is possible, the electrical energy that cannot be recovered economically. If a significant part of the braking energy is recovered, then the amount of UPE can be reduced accordingly to bring further benefits.

Platform Screen Doors are often incorporated into underground station design as they have a safety and operational benefit. They do have an impact on the ventilation depending on whether they are full height sealing the track way or part height.

In the case of underground stations without full height Platform Screen Doors (PSDs), the movement of the trains draws air through the station entrances at ground level, ventilating the public areas. This can be sufficient to maintain acceptable air temperatures in the public areas for the comfort of the passengers.

Full height PSDs reduce the train heat in the public areas of the stations, and also the related ventilation. Where there are heat gains from lighting, escalators and other fixed M&E equipment, along with solar gain through glazed panels, the installation of full height PSDs

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can result in higher air temperatures in the public areas. If the option of full height PSDs is to be carried forward, their implications on the design of the TES and on conditions in the public areas should be reviewed with some care.

Full height PSDs also increase the temperature of the air in the running tunnels, with implications on the operation of the car-borne air-conditioning units, particularly during congested operations. Some metros, particularly those operating in sub-tropical climates, use fan-coil units to cool the tunnels but such complications are less likely in this instance.

If PSDs are considered in future design development a key consideration is whether a single dedicated rolling stock would operate on the line as the doors can only be positioned to suit one configuration. Replacing PSDs to match a new configuration at any future time would require significant rail occupation.

7.11.3 Public and Back of House Areas

With adequate ventilation of the public areas of the underground stations, it should be possible to maintain conditions of acceptable comfort without the use of air-conditioning.

The back of house areas include staff rooms and offices, and technical rooms.

The staff rooms should be ventilated and cooled to normal workplace standards for the comfort of staff who may occupy those areas for the greater part of a shift.

Technical rooms define their own requirements depending upon the equipment contained inside the rooms. Transformers and switchgear are likely to need mechanical ventilation but are able to tolerate control temperatures of 35 or 40oC. Rooms that contain signalling equipment or computers may need to be cooled to 25oC, with the possibility of humidity control and the filtration of dust from the ventilating air. The ventilation of gassing batteries should prevent the leakage of hydrogen from the room.

It follows that, in addition to the ventilation and cooling standards, there may be specific requirements for the ducting of the ventilating air both to and from the rooms. Those requirements, along with the associated ratings for security and acoustic grading, should be considered in the architecture of the stations.

7.11.4 Incident Ventilation Operations

Tunnel Incidents The running tunnels of underground railways are, almost without exception, ventilated longitudinally for reasons of capital cost, and for the effectiveness of smoke control. If the main TVS fans are located at each end of the station boxes, they can be used to ventilate the smoke from either a train fire in a tunnel or at the station, without allowing smoke to pass from one ventilation section to the next. It is important for the TVS to maintain a separation between ventilation sections so that the operating and evacuation procedures can be developed with confidence.

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The length of tunnel between two underground stations has little effect upon the rating of the TVS fans. The number of stalled trains in a tunnel and their blockage ratio do increase the required rating of the fans.

If a tunnel terminates in a cutting, then there should be some form of TVS equipment at the portal to ensure reversibility of the airflow. An alternative to the use of remote fans is the use of jet fans. If used the necessary space for jet fans would need to be available. Jet fans are inexpensive and adaptable, but they are vulnerable to damage during an incident and must be maintained inside the tunnel. However, they are used widely in road tunnels and in some underground railways.

The case of short tunnels raises the need for operating procedures whereby a train is allowed to enter the tunnel only if its way is clear to proceed to the station or to the grade or elevated section outside the tunnel. If there is a risk of congestion, then the train should be held outside the tunnel. AS 4825 suggests that longitudinal ventilation may be necessary in tunnels over 250m in length.

Station Incidents The smoke from a train fire at an underground station is more difficult to capture and to control than in a running tunnel. The reason for this is that smoke has the opportunity to spread throughout the platform area. There are recognised strategies to deal with the situation, though most rely upon the larger air-handling capacities of bulk delivery TVS fans.

If full height PSDs are used, it would be essential to use the OTE to capture as much smoke as possible on the track side of the screen. Smoke that enters the public areas could compromise the tenability of the evacuation and intervention routes, and must be contained as far as is possible. The UPE should not be used, since it would draw smoke down to platform level with immediate consequences on the evacuation routes.

It is often feasible to operate the TVS fans as point extracts at each end of the platform to extract smoke and maintain tenable conditions during the evacuation period. With considered design, the TVS fans can maintain critical airflow velocities at the bottom of the stairs and escalators. The fans draw air from atmosphere through the station entrances and maintain smoke-free conditions to the bottom of the stair and escalator wells at platform level. This is a powerful mechanism that brings the place of safety to the lower level of the station.

Fires on the platform or at concourse level should also be considered. Such fires are classified as suitcase or litter bin fires and, by definition, they are relatively small and easy to deal with. The fire size assigned to such incidents might be 0.5MW or less. The TVS fans can be energised to capture, or to dilute, the smoke from such a fire and to maintain conditions for the safe evacuation of the passengers. Special consideration of the additional fire load would be necessary if commercial activity were to be allowed within the station.

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Inter-station Shafts In the event of a fire on a train that is stalled in a running tunnel, the operator should be able to ventilate the smoke in the preferred direction; driving the smoke over the shorter length of the incident train. If there is a second non-incident train in the same tunnel the choice no longer exists since smoke should not be driven over the second train.

The situation can be avoided if there is never more than one train in a ventilation section. This can be achieved on high frequency lines if the length of the tunnel is 1.0km or less, and there are rules against a second train being allowed into a congested tunnel. Where such a ruling would disrupt the service, or the recovery from a delay, it may be necessary to install one or more inter-station ventilation shafts.

The need for inter-station ventilation shafts depends on the frequency of the service. For the low frequency expected on the Rowville line of 6 trains per hour the maximum 3km between stations may be satisfactory with one or even none.

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7.12 Drainage

Viaducts – drainage may be simply provided by a structural fall in the viaduct deck to outlets above supporting piers and drainage downpipe concealed within the rc piers

Stations – drainage would be as for conventional building drainage except for below ground areas that would require pumped drainage if below the level of adjacent gravity drainage.

Tunnels – cut-off drains across the entry of tunnels would be provided and a sump at the low point of tunnels requiring pumping to the public drainage system. At Huntingdale Station a low point and line sump and pump would be required around 300-400m chainage from the Station.

Open cut – the track area would be a large catchment area requiring careful consideration of drainage for heavy rainstorms. Drainage would be provided by a sump at the low point and possibly intermediate cut-off drains and sump with sump pumps pumping to the public drainage system.

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8. Signalling

8.1 Basis of Design

The document ‘Summary of Rowville concept timetable modelling assessment’, prepared by Public Transport Division, identifies that 3 trains per hour in each direction can be provided between Rowville and Flinders Street with the current signalling system on the Dandenong Rail Corridor. To provide a greater number of services on the Rowville line the capacity of the Dandenong Rail line would need to be increased. Implementing ETCS Level (2) could be one possible solution.

Based on the above, this investigation would be limited to the area between tie in point to Dandenong Rail corridor and Rowville.

Additionally, this signalling investigation is based on the following requirements:

Requirements for the new branch line to Rowville, and tie in point between Oakleigh and Huntingdale on the existing Dandenong Rail Corridor.

Service frequency would be up to 3 trains per hour in each direction Line speed of 110kph Track gradient is 2% maximum Additional track work for new line:

Two uni-directional tracks (one up and one down) Six sidings on the up end of Rowville Two crossovers on up end of Rowville

8.2 Existing infrastructure

The Dandenong Rail Corridor currently consists of 4 tacks from Flinders street to Caulfield Station and two tracks to Dandenong.

The signalling infrastructure arrangements along this corridor comprise of track side signals and train stops. A combination of 3 and 4 aspect signalling has been provided from Flinders St to Huntingdale.

Signalling interlocking systems along the corridor consist of the following:

Caulfield – SSI interlocking and Signal Control Panel Oakleigh – Geographic Relay interlocking and Signal Control Switch Panel

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8.3 Implementing new Rowville Rail Link

In order implement the new Rowville Rail Line, and provide the required operational requirements, two options were considered for the signalling infrastructure. The options were as follows:

Option 1 – Extension of existing signalling Infrastructure Option 2 – Provide next generation signalling system These options are further discussed below.

Option 1: Extension of existing signalling Infrastructure This option would involve modifications to the existing signalling infrastructure on the Dandenong Rail Corridor, and extending the existing signalling through to the new line to Rowville.

To implement the new line, a link would need to be established between Oakleigh and Huntingdale stations. Accordingly, the existing signalling infrastructure at the station would need to be modified. This would involve the following:

New Turnouts to tie in to the Dandenong Rail Corridor Modification to the interlocking at Oakleigh Modifications to signals between Oakleigh and Huntingdale Stations. Potential upgrade of local signalling power supply Interfacing between interlocking at Oakleigh and Rowville

The signalling infrastructure required for the new line would be based on meeting the operational requirements of 3 trains per hour. To achieve this, the following infrastructure would probably be provided:

Computer based interlocking system at Rowville, to control the entire line up to the interface at Huntingdale.

Local control centre at Rowville. Object Controllers and signalling equipment boxes distributed throughout the Rowville

line 3 and 4 aspect way side colour light signalling Mainline signals spaced at a nominal spacing of 1.4km Dwarf signals for sidings Train detection equipment Active train protection via train stops 2 Crossovers on the up end of Rowville to accommodate train turn around and siding

moves. Trail rollout protection for sidings The 3 and 4 aspect way side signalling with a signal spacing of 1.4km would meet the operational requirements for the new Rowville rail line and cater for 3 trains per hour.

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Notwithstanding this, it was concluded taking this approach would be appropriate, for the following reasons:

Utilising 3 and 4 aspect way side signalling for the new line would maintain consistency with the Dandenong Rail corridor rail system

Maintaining a nominal signal spacing of 1.4km would be consistent with the Cranbourne and Pakenham line signal spacing.

A level of future proofing would be provided for the line, as the number of services can be increased without requiring new signalling infrastructure

Option 2: Provide next generation signalling system This option is based on providing a next generation signalling system for the new Rowville Rail Line.

There are a number of different solutions available from different manufacturers that can be considered next generation signalling systems. To date, there has been no direction provided regarding a particular type of system, or even the requirements for the system.

Notwithstanding the above, as highlighted in the design basis, the document ‘Summary of Rowville concept timetable modelling assessment’, prepared by Public Transport Division, ETCS Level (2) has been identified as a system that may need to be implemented on the Dandenong Rail Corridor, to enable the required services to be provided to Rowville. Accordingly, the next generation signalling system that would be considered for the new line would be ETCS Level (2).

As with Option 1, modifications would need to be undertaken at Huntingdale station, to implement the link to the new line. The changes required at this location would be similar for this option.

In relation to the new rail line, rolling out ETCS Level (2) would require the following infrastructure to be provided:

Retrofitting rolling stock with driver panels, communication and processing units, and sensory equipment

Installation of track side transponder units Installation of radio block centres Computer based interlocking system at Rowville, to control the entire line up to the

interface at Huntingdale

Comparison of Options In comparing the required signalling infrastructure for the two options as highlighted above, there are a number of benefits and limitations with each. These are further described below.

Extension of existing signalling Infrastructure Retaining and expanding on the existing signalling infrastructure has a number of key benefits. This includes the following:

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Existing rolling stock can be utilised and no modifications will be required Drivers will not need training to operate a new system Maintenance will not need training to maintain a new system Project risks will be reduced, as a tried and tested system will be utilised Risk on impacting existing train service operations will be reduced Staging and rollout of project will be simpler There will be no interfacing issues between two different types of signalling systems New technology will not be put into the system, that may conflict with the direction and

planning of system rollouts across the greater network in the future

There are also a number of limitations in retaining and expanding the existing infrastructure. This includes the following:

The infrastructure would not be able to provide as high a capacity as a next generation signalling system

Expanding the existing system on the new line would provide infrastructure that may become redundant, if a new system is rolled out on the network on the future

Rollout of ETCS Level (2) Replacing the existing infrastructure with ETCS Level (2), and providing this system for the new Rowville rail link would have a number of key benefits. This includes the following:

It would provide a relatively higher frequency service The system would have the ability to increase line capacity, without significant changes

to the infrastructure Providing a new system on a Greenfield site is easier to implement and has lower risks

than on an existing line. Accordingly, this project would be a good opportunity for the trial of a new system that can be rolled out to the remainder of the network.

There are also a number of limitations associated with providing ETCS Level (2). This includes the following:

Existing rolling stock cannot be utilised in their current configuration, and modifications will be required

Drivers will need training to operate the new system Maintenance will need training to maintain the new system Project risks will be increased, as a system that has not been previously implemented or

proven on the network will be utilised Risk on impacting existing train service operations will be increased Staging and rollout of project will be more complex There will be interfacing issues between two different types of signalling systems, that

will need to be addressed The new technology may conflict with the direction and planning of future system

rollouts across the greater network

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Conclusion Based on a comparison of the benefits and limitations of both options above, the option to extend the existing signalling infrastructure is the most appropriate for this project.

Whilst it has been identified that a Greenfield site would provide an opportunity to trial a new system without directly impacting existing rail services, providing a next generation signalling system would have an impact on the wider network. As such, determining the feasibility of providing this system cannot be isolated to this new line alone. Consideration would need to be given to the requirements for the entire Metropolitan network, and a viable solution that can be rolled out to all rail lines in the future.

Other Considerations The requirements and benefits of bi-directional lines was considered for the new line.

Bidirectional running allows the up and down peaks to be catered for better, but it relies on storage of trains at Rowville to gain any benefit. Also, the service constraints are likely to be on the Dandenong line, and not on the new Rowville line.

Based on the above, it was concluded that there would not be a significant benefit in implementing bidirectional train running, and unidirectional would suffice for the current operational and service requirements of the new Rowville line.

Concept Signalling Scheme A concept signalling scheme based on the preferred option (i.e. Option 1) has been developed and can be referred to in Appendix B.

The scheme meets the requirements for three trains per hour, based on using existing signalling principles and system.

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9. Traction Power and Overhead Line Electrification

This section identifies new traction power and Overhead infrastructure required by the Rowville Rail Study including associated works needed on the existing Dandenong Rail Corridor at tie in locations.

As the interfacing electrified network is 1500 V DC; it is pragmatic to assume that the Rowville Line would be a compatible 1500 V DC system.

The Rowville Corridor route length is nominally 12km. It would interface with the mainline at Huntingdale Station, although track configuration would require a complete rebuild of the station in the up direction. The design of the Overhead infrastructure requires consideration of track in open route, viaduct, cut/cover and tunnel.

9.1 Power

The 1500V DC reticulation is supported by substations and tiestations.

9.1.1 Tie Stations

In broad terms a tiestation is a substation without a high voltage supply. The principle function of a tie station is to mitigate voltage drop and provide electrical protection.

9.1.2 Substations

Substations provide:

high voltage AC panel 1500 V DC panels and transformers/rectifiers high voltage AC signal power panel local low voltage AC power panel for lighting and power SCADA panel for remote monitoring and control of the above electrolysis panel negative return and earthing

The upstream side of the substation high voltage AC panel would be supplied at a voltage of 22 kV AC by the local electricity distributor. For this corridor this is likely to be United Energy.

Substations provide traction power for trains through the Overhead conductors. Trains pick up power from the Overhead conductors by means of pantographs mounted on the train roof. Within the train the traction motors use the power with the return circuit to the substation via the train wheels and rail.

Power is provided in discrete electrical sections with the up and down mainlines on different sections. Sectioning occurs at substations via open overlaps in the Overhead. Where tracks are joined by crossovers, electrical sectioning is afforded by section insulators. Sectioning is

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primarily for electrical protection purposes monitored and controlled by instrumentation but is also used for isolating sections of the network for maintenance and other purposes.

As a general rule substations are required at:

the end of sections which includes the end of lines places of high load such as stabling yards junctions to provide separate electrical sections for converging routes and security of

supply for the main lines in (n-1) substation failure mode

Apart from the above principal substation positions, substations or tie stations are required at 4km nominal separation.

9.1.3 Rowville Line Power Requirements

The number and location of substations or tie stations would be determined by network analysis at the preliminary design stage.

There are existing substations at Oakleigh and Westall, 4.8 km apart. The existing Huntingdale Station is 900m on the down side of Oakleigh Substation. If Huntingdale Station is to be rebuilt in the up direction, Oakleigh Substation should also be considered for rebuilding to suit the Rowville electrification.

Up to three other sub/tie stations would be required with the following considerations:

design would be for the normal timetable with one substation offline. This is the (n-1) failure scenario. Future proofing should also be considered

substations should be totally enclosed with each 22kV supply from a different source to its neighbours

location of substation would be somewhat governed by availability of a 22kV source if tie-stations are used they should be future proofed with space provided for conversion

to substations at a later date substations on the surface would be considerably cheaper than those underground

because: no excavation required specification for equipment and fire rating is less onerous access should not be an issue

From a power perspective twin track provides more security to the traction system because:

there is more copper available for supply and hence mitigation of volt drop for negative return there is double the rail area available for the return path to the

substation and additional security of the conductor path With a new line the power system design should consider the catenary and contact traction conductors without the need for additional (supplementary) along track feeders.

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Table 3 lists the cabling that is required for traction systems.

Application Conductors Comments

22kV substation supply cable

Triple core insulated 185mm² aluminium conductors with copper screen. XLPE/PVC insulation/ sheath

Usually between supplier’s metering pole and the AC panel of the substation

Substation feeder cables to mainline

Single core insulated 400mm² aluminium conductor with copper screen. XLPE/PVC insulation/ sheath

Two cables per electrical section

Substation feeder cables to stabling

Single core insulated 400mm² aluminium conductor with copper screen. XLPE/PVC insulation/ sheath

Three cables per six stabling roads each holding a 6-car set

Track to substation negatives

Single core insulated 300mm² aluminium cables from track to the negative pillar. 400mm² aluminium cables from negative pillar to substation. XLPE/PVC insulation/ sheath

Number of cables to be determined by power system design. For estimating consider the number of negatives to be the same as the number of positives

Electrolysis Single core 150mm² copper XLPE/PVC insulation/sheath

Electrolysis on open route is generally bare aerial 210mm² aluminium supported on the Overhead structures

Substation feeder cables to signalling system

Up to 2.2kV AC

Table 3: Traction System Cabling

9.2 Electrolysis

Overhead traction power systems provide power at the pantograph for the traction motors with the return circuit to the substation via the rail. Current return would be through the path of least resistance. In a perfect world all the traction return current would be through the rails, however, in reality some of the return current is through the earth and any conductive material of utility service lines that happens to be conveniently situated. This is termed stray current. The nature of DC power results in pitting of the conductive material where the current leaves the utility service on its path back to the substation negative bus and is termed electrolysis.

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Electrical Safety Victoria requires the Accredited Rail Operator (ARO) and utility companies to collaborate to mitigate stray current corrosion. Area tests would establish the need for any mitigation following commissioning of new lines and changes to the timetable.

Appropriate mitigation measures may include:

drainage bonds from 3rd party assets to the rail an aerial conductor back to the negative bus of the substation 9.3 Overhead

Overhead would generally be to the current mainline standard which requires a weight regulated catenary and contact. However, a weight regulated catenary and contact may be inappropriate in the tunnel or cut and cover sections due to greater space requirements for this type of conductor system. To minimise costs, the tunnel section would require consideration of a conductor beam. Subsequently, this system would also require type approval from MTM.

Figure 20: Typical ‘Open route’ Overhead

Generally conductor sizes and fittings should be to the current standard to avoid stores and maintenance issues in the future.

There would be five route conditions to accommodate:

interface with Dandenong corridor (mainline) open route

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elevated and viaducts tunnel and restricted space stabling

9.3.1 Conductors

Table 4 below summarises the different route types and the associated conductor systems to be considered.

Route type Application Conductors Comments

Mainline open route and elevated viaduct

Catenary and contact wire

37/2.50 catenary, 161mm² contact both hard drawn copper

Weight regulated to 20kN and 15kN respectively

Tunnel, cut and cover, and restricted space

Wire option: Catenary and contact wire

37/2.50 catenary, 161mm² contact both hard drawn copper

Weight regulated or gas anchored to 12kN and 12kN respectively

Conductor beam option:

Aluminium conductor beam with 161mm² contact wire

Non-tensioned contact wire. Total copper equivalent area is 1200mm². This option requires type approval from MTM

Stabling areas Catenary option:

Catenary and contact wire

37/2.50 catenary, 161mm² contact all hard drawn copper

Weight regulated to 12kN and 11.2kN respectively

Tramway option: Trolley system

161mm² contact wire only

This option requires type approval from MTM

Table 4: Overhead Conductor Systems

9.3.2 Interface with Dandenong corridor

Huntingdale Station would be rebuilt in the up direction to suit the Rowville junction track changes. It is likely that most of the existing Overhead support structures in the area of the junction would be replaced with new infrastructure. New tension lengths from the Rowville line would be fully weight regulated and would interface with the Dandenong mainline tension lengths on the up side of the new Huntingdale Station. Sectioning requirements would require either section insulators or overlap interfaces.

9.3.3 Open route

The catenary and contact conductors are supported at spans of not more than 70m with the contact height varying from an absolute minimum of 4.42m to not more the 5.8m on

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mainlines. The ‘normal’ conductor height is taken as 5.2m. Because there would be no grade crossings there is no requirement to lift the wire above a height of 5.2m on this route.

Maximum tension length would be 1200m in accordance with the Overhead Standard.

9.3.4 Elevated and viaducts

The catenary and contact would be similarly supported as for the ‘Open route’. However, elevated tracks and viaducts increase the risk of conductor displacement by wind (blow-off). The mitigation strategy is to design shorter span lengths and lower the wire height to reduce effect of vehicle sway of the pantograph at contact wire height. Span lengths for elevated tracks can be taken as 60m with a contact wire height of 5.0m which would suit an operating wind speed of 35 m/s. These conditions provide the same security as a 70m span at 5.2m for an operating wind speed of 28 m/s.

9.3.5 Tunnels and restricted space

The cost of tunnelling is related to area of excavation and hence diameter of bore. The diameter of the bore would depend on:

Top of rail height below tunnel centre (how close can the track be to the bottom of the tunnel)

Overhead above pantograph, considerations include: Vehicle height Minimum operating height of pantograph Overhead encumbrance Insulation depth

The rail height below tunnel centre would be dealt with elsewhere in this document.

Rollingstock gauge for the electrified network, mm 4270 Electrical clearance, mm 150 Minimum contact height, mm 4420

The above minimum contact height needs to account for vertical curves, bounce, tolerances, sags due to temperature and strain creep. For the current level of design it would be appropriate to use a minimum contact height of 4500 mm in tunnels.

There are usually three Overhead options considered for tunnels, cut and cover and other areas of restricted clearance:

Wire options - catenary and contact conductor - Fixed terminated (as found in the Melbourne Underground Rail Loop) - Auto tensioned (to be developed for MTM system)

Conductor beam (to be developed for MTM system)

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Fixed terminated catenary / contact (MURL): This system is no longer appropriate for future applications because the contact wire sags at temperatures above 15°C to an extent dependent on timetables, gradients and size of trains. This indeterminacy poses an unacceptable risk to future requirements

Auto tensioned: For tunnel section, the system requirements would be:

span length, maximum 35m contact height, minimum 4500 mm catenary height, maximum 5100 mm Typical tunnel internal diameter is expected to be in the order of 6200 mm. This equipment would use existing OCS fittings but would require supporting brackets to be developed.

Figure 21: Auto tensioned tunnel equipment

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Conductor beam: For tunnel sections, the system requirements would be:

span length, maximum 12m contact height, minimum 4500mm

For this equipment a typical tunnel internal diameter is expected to be in the order of 5800 mm. However, minor additional tolerance needs to be included to accommodate lack of tunnel roundness and other construction impediments to installing a level conductor bar. The conductor beam has not been used in Melbourne to date but it is used throughout Europe, Japan and recently in Shanghai. In Hong Kong, MTR are considering replacing their existing tunnel catenary / contact system with a conductor beam.

Figure 22 and Figure 23 below show the pantograph sway profile with a conductor beam, and an example of the Kyoto Overhead tunnel system.

Figure 22: Conductor beam with swayed pantograph head outlines

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Figure 23: Conductor beam, Kyoto

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Table 5 compares the wire option and conductor beam system in tunnels

Element / considerations

Catenary / contact Conductor beam

Static interface

Minimum tunnel diameter. This ssumes 4.5m contact wire above vehicles not higher than 4.27m

6200 mm. Other diameters may be possible but require specific detail design to prove

5800 mm. This is subject to detailed design

Contact wire to crown 700 mm 350 mm

Supports, maximum spacing

35 m 12 m

Adjustment Gradients by setting dropper lengths

Gradients required to be built into supports

Tension 12kN/12kN catenary/contact

None

Tensioning arrangement Weights or gas anchors None in tunnel. Transition element needs to transfer above ground tension to a convenient anchor position

Construction 1200m continuous lengths of conductor

Furrer+Frey system. 12m (11.9m) length sections bolted together. Contact is clipped to the underside of the beam. Siemens system solid beam does not require a separate contact wire.

Safety interface

Conductor drop zone (European standard)

Potential risk for emergency walkway and at platforms

Unlikely to be an issue

Dynamic interface

Stiffness Elastic Rigid

Resonance Existing system and understood

Resonance is a known problem requiring damping

Transition, tunnel to above ground

Overlap at portal. Dynamically similar systems

Overlap at portal. Stiffness of beam needs to be decreased incrementally to match that of the elastic

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system

Pantograph interface

Pantograph stiffness Existing system and understood

The existing Melbourne pantograph has a relatively stiff head and may have a poor response to a conductor beam resulting in greater attrition rates on carbon and copper

Pantograph running height in tunnels

4500 mm 4500 mm

Speed 80km/h 80km/h

Electrical interface

Conductor area, basic configuration, copper equivalent

342 mm² 1300 mm²

Sectioning Overlap or section insulator

Overlap or section insulator built into the beam. Clearance to tunnel crown above beam would need consideration

Clearances 100mm static and passing 100mm static and passing

Tertiary insulation if needed

Built into supports with 70mm² double insulated bond wire to spark gap

Built into supports with 70mm² double insulated bond wire to spark gap

Cost interface

Number of supports 35 m spacing 12 m spacing

Maintenance availability Same material as above ground

New range of fittings inventory. New tooling

Contact wire Solid 161mm² Solid 129mm² maximum. 161mm² may be too big for Furrer+Frey system. Not required for Siemens system.

Corrosion interface

In particular corrosion to minerals in a solution expected to be found in the ground water

Copper is relatively stable. Insulators and other support fittings may need shielding in wet areas

Furrer+Frey system. Aluminium would corrode with salts and concrete wash from roof. Requires

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percolating into a tunnel environment

plastic shield above beam. Copper contact wire and aluminium beam require greasing on installation to mitigate bi-metal corrosion. Drainage holes are provided in F+F beam to remove condensation which may ultimately form an electrolytic solution

Risk interface

Contact wire burn through Possible at feeding overlaps but can be mitigated

Unlikely to happen because of the configuration of the overlaps

Rip down of equipment due to faulty pantograph

Possible Unlikely

Table 5: Tunnels. Comparison between catenary and conductor beam systems

9.3.6 Stabling

Overhead in stabling yards should match the mainline. That is, the system should be a fully weight regulated catenary and contact but at lower tensions to accommodate large radial loads.

There is a potential option of designing a trolley system for stabling roads. Although this is not in use on the current electrified system, this would require development, risk analysis and type approval from MTM.

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10. Railway Communication

Information and Communication Technologies (ICT)

The requirements for ICT communications systems of the stations would be designed to meet the future requirements of the DOT Control and Information Systems (CIS) Strategy.

The station ICT requirement would focus on the following CIS applications:

Passenger/Staff Safety Station CCTV Car park CCTV Emergency help point Tunnel CCTV Tunnel emergency phone Tunnel radio coverage

Passenger Information System (PIS)

Passenger information display Public Address (PA) announcement Train arrival PA announcement Train running information help point

Control of the Train Network

Train radio communications Station Operation

Station security Station voice service (phone) Station data service (workstation)

Integrated Transport Management

Systems have information sharing and networking capability The station ICT systems that support the CIS are as follows:

Digital CCTV video surveillance system Passenger information display system (PIDS) Public Address (PA) announcement system Customer help points (CHP) Station clocks Radio system PABX telephone system LAN data network

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Access control system Security alarm system Communications equipment room (CER) facilities Telecommunication cabling The main station ICT systems are represented on the ‘Station ICT IP System Overview’ diagram (Figure 24).

The cost allowances for these ICT systems are shown in Table 6.

Service Total NotesStations 47,080,000$ 4 stations car parking only at Huntingdale and Rowville Tunnels 34,978,000$ 2 tunnels, 6.4km eaTrackside 1,400,000$ New FOC run on above ground sectionsMETROL 1,990,000$ expand existingS.C.R. 2,460,000$ Option - A new Security control roomELECTROL 1,990,000$ expand existingMtce Rm 2,590,000$ A new maintenance roomEmergency Control Room 9,840,000$ Emergency Control Room located at each station

Total ICT Cost 102,328,000$ Include design and construct

Table 6: Cost Allowance for ITC Systems

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Figure 24:Station ICT IP System Overview

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11. Constructability

11.1 Project Timeline

The high level delivery schedule provided in Appendix D is based on a final alignment comprising a mix of at grade, elevated and underground sections. Underground sections are assumed in cut and cover which provides the best mix of risk, cost and production rates for underground sections of the construction. Further detail in relation to this view are provided in the next section of this Constructability Review.

Exchanging a cut and cover tunnel technique for bored tunnel would be expected to increase this program duration by a minimum of 12 months, due to the lead time in procuring and commissioning tunnel boring machines. Similarly any excavated bored tunnel would also have impacts on the overall duration of delivery.

Taking into consideration further project feasibility and options assessment, stakeholder and industry consultation and a commercial tender period, followed by contractor detailed design development, etc. best case for construction commencement is early to mid 2016 with construction then taking a little over 4 years including an allowance for integrated systems testing and commissioning (ie. completion early 2020).

It is noted that there is opportunity to consider a phased commissioning with a partial completion and handover of the corridor at say Monash Station. Such an approach would require a terminating track arrangement to be built into the configuration at this location. This alternative has not been considered at this feasibility stage assessment.

11.2 Noise and vibration impacts

The table top geotechnical investigation completed along the alignment indicates the western end of the alignment from Huntingdale station for the first 9 km through to Dandenong Creek (which covers 2 sections of tunnel construction and one section of elevated structure) is expected to be predominantly Tertiary Brighton Group soils comprising sandy clays and clayey sands. To the east of Dandenong Creek for approximately 2km, residual soils overlying inter-bedded silt and sandstones are anticipated.

The likelihood of vibration transmission either during construction works, or during subsequent operation of the train line are likely to be more significant in the harder siltstone sandstone materials to the East of Dandenong Creek due to the harder nature of these materials.

A detailed analysis of the vibration transmission characteristics of each geotechnical medium against the different structural designs (ie. tunnel type, elevated structure, at grade track, etc.) is unlikely to establish definitive results as to the possible effects of vibration within the corridor, however a risk assessment undertaken where known sensitive buildings and or stakeholders assets are identified would enable key areas of interest to be pinpointed so that

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attenuation responses could be factored into the design development and construction methodologies when working over or near these locations. For example, pier footings for elevated structure over rock could be founded on pad footings so not to extend into the underlying rock material. Various train vibration dampening options are also available and able to be selectively allowed for in the track structure design. Further discussion on controlling noise and vibration is included in section 7.0 Civils Structures Required.

11.3 Temporary access Shafts

11.3.1 Cut and Cover Tunnel

There are various options available for temporary access to cut and cover construction works along the route with the preferred locations being to use either tunnel portals (provided sufficient work and storage areas and workable road interface is available), or otherwise access pits where required along the route.

The area to the south side of North Road at approximately 18.600km (in the middle of the ramp loops) could provide a viable access site for materials management in and out of the tunnel for the majority of tunnelling works between Huntingdale Station and the Portal at 21.250km. If this access location is to be used, agreement would need to be reached with MTM for extended closure of the car park, and the associated Council for either closure to or changed traffic conditions at the Huntingdale/North Road ramps.

For the remaining sections of tunnel construction, tunnel portals would be used for management of materials for the tunnel section at Waverley Park, and the tunnel portal for the tunnel through to Rowville Station.

In addition, cut and cover tunnel provides the flexibility of creating access points at any location along the route by leaving out a section of soffit roof slab for later completion.

11.3.2 Road Header Tunnel

The section of tunnel into Rowville Station may be founded in sufficiently hard rock to enable mined tunnel using a road header. The tunnel portal location at 30.200km would be used exclusively as access for this purpose.

11.3.3 TBM Tunnel

A pit is generally required to launch the TBM at working depth. The greater depth of TBM tunnel provides fewer options for launch pit along the route which as a consequence may drive the use of a station pit for this purpose.

It is noted that if a station pit is used for this purpose, it typically places the station construction on a critical program path, as well as making the station construction staging more complex to facilitate the tunnel construction works.

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If TBM tunnel approach was to be used a deeper route alignment would likely be required to provide sufficient surface settlement resistance. Deeper tunnel would also result longer and more continuous tunnel. Alternative vertical alignments for TBM tunnel beneath Blackburn/Springvale Roads and Jacksons Road are shown on the alignment long section.

Under this scenario, temporary access for TBM launch, and materials management in and out of the tunnel would likely be required at a number of stations along the route. Also, deeper tunnel would result in deeper stations, which introduces further choice of station construction approach, which may further constrain the ability to access the tunnel for the TBM works.

Ideally, a single access point for each TBM tunnel section is preferred with the completion point tied into a portal so the TBM can be extracted more efficiently at ground level. This would see either Huntingdale station pit, or the Monash station pit being used to launch the TBM for the western tunnel section, with an option of a temporary pit to the south side of North Road at approximately 18.600km (in the middle of the ramp loops) also being suggested as a viable location in lieu of Huntingdale station. Waverley and Rowville stations would likely be used to launch the TBM for the central and eastern tunnel sections provided open pit construction is viable for the resultant station depth.

11.4 Construction Method

11.4.1 Overall Alignment Considerations

Various constraints such as designated route, station locations, road crossings, and other stakeholder requirements have driven the selection of structural solutions based on the position of the route vertical alignment. This has resulted in limited options for structural approach at some locations (e.g. down the centre of North and Wellington Roads). Notwithstanding, the concept alignment has been developed with the goal of minimising construction costs through an optimised mix of elevated structure, cut and cover tunnel and bored/mined tunnel solutions, whilst also ensuring that station depths are not too deep to enable cut and cover approach to station construction.

11.4.2 Station areas

Huntingdale, Monash, Waverley and Rowville would be below ground stations with depths set to enable cut and cover station construction technique. Mulgrave is would be an above ground station which would be elevated in conjunction with the elevated route structure at this location.

Cut and Cover Stations For underground stations, cut and cover construction technique is generally cheaper and easier that the alternatives of cavern or tunnelling construction approaches which would be required for deeper station depths. In addition, deeper stations result in increased operating costs due to ventilation requirements and greater vertical transport infrastructure costs.

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Deeper stations also result in greater commuter travel times between ground and platform levels.

Regardless of the stations depth and construction approach, there would be a significant interface with the tunnel construction works which would require formal consideration with respect to staging of the works. This interface can be minimised by avoiding the need to use the station pits as access points for the tunnel construction works.

In the event that a station pit is required for access to tunnelling works, the associated station construction is likely to be pushed onto the program critical path. The preference is to avoid this if possible through use of other temporary pit locations, or otherwise the tunnel portal locations for materials, plant and personnel access into and out of the tunnels. It is noted that if TBM tunnel boring technique is used, one or more station pits would almost certainly be used.

The underground station footprints allows for centre platforms. A centre platform would require the lead in tunnel alignment in cut and cover tunnel to be widened as well, while bored tunnel would already be set at the required separation. The two underground stations (and lead in tunnels) on North and Wellington Road would extend well beyond the centre median under the existing road alignment which would require extended road closures during wall and roof construction works. To minimise the impact of the station construction works, a top down construction technique is preferred for the station pits.

The desktop geotechnical study shows that the majority of the station pits (with exception of Rowville Station) would be in clays and sands, and that this would be the worst case for pile embedment. In the permanent condition the Station walls would be braced by the soffit/roof, concourse floor and track invert slabs. The design also assumes permanent ground water table at 5m depth (this would have a significant effect on design).

The confined sites for the various underground stations largely precludes construction in open cut. Additionally, the high water table would require water proof tunnel walls. Either an in-situ reinforced diaphragm wall constructed under bentonite slurry or a secant pile walls could be used to achieve this. Secant pile walls are seen as offering the best option given the confined space and the capacity to install piles within trafficked roads under short lane or road closures.

Secant pile walls can be constructed as a hard-soft pile walls or continuous hard pile walls. In hard-soft secant walls the male piles, hard reinforced concrete, cut secants into the female piles (soft piles, grout/bentonite mix). The hard-soft technique is seen as appropriate for this project as the piles can be constructed using continuous flight auger (CFA) techniques. CFA construction allows the use of construction plant common in Australia and would minimize construction duration.

Station pit construction could be completed bottom up with cantilevered, propped and/or tied back pile walls or top down, however top down construction offers the most appropriate

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solution for the project. The principle advantages, of top down over bottom up construction, are:

Return of the roads and tunnel cover to finished conditions in the shortest time. Minimises disruption to the public and adverse effects on the amenity adjoining

properties. Minimises of the need for props and or temporary anchors to the wall Minimisation of wall deflections and hence ground movement effects on adjoining

structures and services. Minimisation of ground water draw down and hence settlement in nearby soils.

In addition to side and end wall secant piling, a series of either permanent or temporary roof slab support piles would also be required closer to the centre of the station pit. Specifics of the depth and placement of these needs to take into consideration the overall staging of the station such that appropriate soffit / roof and concourse floor slab support are maintained throughout.

The station wall piling and Soffit roof slab would be constructed one side at a time to avoid lane closures to both traffic directions. The piling works at road level would be performed in off peak traffic periods with pile holes and piles covered with road plates where installed in existing road lanes when opened to traffic. Minor speed restrictions would also be applied.

Piles would be finished nominally 1.5 to 1.8 metres below road surface to allow sufficient depth for services relocations and new future services.

Once all piles are completed, off peak lane closures would again be used to drive sheet piling behind the pile wall to support the road lane adjacent during the excavation and installation of a partial soffit/roof slab over the sections of the station box that lie under road traffic lanes.

Once the partial roof slabs are in place and lanes returned to traffic, excavation of the platform station pit would take place through the centre gap in the roof slab with the adjacent lanes returned to normal traffic operations. The remainder of the station construction would occur progressively with excavation being completed on a level by level basis.

The total depth of piles would need to be 8 to 10 metres deeper than the rail level through the station, or a total depth of 20m plus.

The wall piling would require concourse floor slab and track invert slab support arrangements to be built in at the required height. This is achieved through use of plastic blockouts in the piles which are removed once excavation is complete, reinforcing bars are then bent out to act as starter bars for the slabs, alternatively reinforcement couplers can be used. The concourse floor slab and track invert slab also act as strutting support for the side walls.

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The concourse floor slab would be built in segments to facilitate access to the lower platform levels for excavation and construction works to be completed.

The platform level would then be excavated to full depth with track invert slab and platform then constructed from the bottom up including any required track and platform structure support arrangements. Concourse floor and soffit/roof slabs would then be completed followed by station mechanical and electrical fit-out, services, etc.

Huntingdale and Rowville Stations would also be cut and cover using secant piling for the station box walls. Location constraints in both cases are however different to the station pits through North and Wellington Roads.

With Rowville Station being situated under the shopping centre carpark, piling and soffit slab construction should be significantly less constrained, allowing for an simpler approach to construction staging. Otherwise approach to construction would be identical to the North and Wellington Road Stations.

At Huntingdale, new station platforms under the existing above ground platform introduces significant complexities. It is anticipated that temporary closure of the existing station would be required in conjunction with temporary realignment of one or both tracks through the station to enable demolition of the existing platform to make way for a new multi level railway station with below and above ground platforms. Further consideration is given to the operational impacts at Huntingdale under Section 11.8.

The overall approach to station pit construction at Huntingdale would be very similar to that in the North / Wellington Rd Median with the exception that railway tracks are being diverted and supported while the wall piling and roof slabs for the below ground platform are constructed.

One concept for staging the construction of Huntingdale Station is as follows, with new platforms being located beneath existing. The station would be closed to passengers with a temporary realignment of the Down to the North side of the station in the station car park area sufficiently clear to provide safe working area. This would require a series of temporary overhead structures, and movement of signalling infrastructure, etc. It is likely to require land acquisition outside of the existing VicTrack boundary.

The new Down side platform would then be constructed with a temporary piled wall down the centre of the station to support the Up track which also continues to operate. Once the sofit / roof slab over the Down side (below ground) platform is complete, the Up track could then be moved to the Down side of the station to enable the Up side of the station, below and above ground to be constructed.

Elevated Station Side platforms are shown for Mulgrave station. The associated platforms, stairs, ramps and lifts would be constructed following construction of track structure. It is assumed that starter reinforcement would be provided via blockouts in the precast pier and viaduct structures for

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this purpose with the respective station structures then built from ground up and tied into the piers and viaduct structures as required.

Station Services Installation of station services are generally delayed until completion of the main station construction and also in the event station pits are continuing to be used as servicing points for tunnelling works.

Once the station structural works are completed and released, the services fit-out, including station transport infrastructure, lighting and electrical, water and fire services, ventilation systems, etc. are able to be installed. Ducting for services routes would be built into the structural members of the station build to facilitate services and equipment installations when they occur.

11.4.3 Below Ground Alignment

The alignment options contemplate tunnel structure between:

the new Dandenong line connection at Huntingdale and east of the Monash station beneath the Waverley Park area of Wellington Road beneath Stud Road into Rowville station.

The Stud Road tunnel would be either a short length crossing Stud Road (the Golf Course North approach) or a longer tunnel running along Stud Road (the Wellington Road approach).

Cut and Cover Tunnel Construction All tunnel sections are considered shallow enough to utilise cut and cover tunnel construction techniques with a maximum viable depth to invert slab from ground level of approximately 20 metres. It is noted that typically the tunnel depth is less than 15 metres, with the average closer to 12 metres.

Notwithstanding the alignment could be lowered sufficiently to enable boring tunnel technique, in which case the approach detailed in the next section would become applicable.

Figure 2 provides an indicative cross section for cut and cover tunnel.

From a construction perspective, this design provides a significant flexibility in approach. This is particularly important for the alignment down the centre of North and Wellington Roads which provides only a narrow area between the western and eastern traffic lanes. With the requirement to work between operating traffic, there is an expectation that lane closures would be required on both sides of the construction works for periods of time. The goal in construction would be to minimise such lane closures, and traffic management costs during the construction.

As with the station pits, the desktop geotechnical study shows that much of the alignment is in clays and sands which is the worst case for pile embedment. The design for budget

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purposes assumes 12m effectively retained to the underside of the base slab. In the permanent condition the tunnel walls would be braced by the soffit and invert slabs. The design also assumes permanent ground water table at 5m depth (this would have a significant effect on design).

As with the station pits, hard-soft secant piling technique with top down construction is seen as appropriate for this project (see section 11.4.2 Cut and Cover Station Cover for further details).

The construction would proceed on a section by section basis (say from cross street to cross street). Following completion of any required services diversions, one side wall would be constructed first followed by centre piles then the second side wall. This would enable single lane occupations one side at a time. Piles and pile holes would be protected by road plates when returning lanes to traffic. Minor speed restrictions would also be applied. Piles would be completed nominally 1.5 to 1.8 metres below road surface to allow sufficient depth for any delayed services relocations and new future services installations.

Once a section of wall and centre piles are complete, extended closures would be used to excavate and cast soffit slab and apply waterproof membrane. Additional sheet piling would be driven in behind the pile wall acting as a cantilever to support the road lane adjacent. The design provides the flexibility for this to be completed either full width (lane closures both sides), or in 2 halves (one side lane closures).

The soffit slab could be installed, either as pre cast sections, or poured in situ. Poured in-situ, is preferred. A surface blinding layer of low strength concrete and bond breaker would be installed before soffit slab casting for later removal during tunnel excavation.

As each section of tunnel is complete, it is released to the underground excavation crews working from the main access point. Excavation would be completed using bucket wheel excavator typically extracting spoil via a conveyor system that would transport the loose spoil to the access point. The conveyor system would be hung on one of the tunnel walls to keep it clear of other tunnel activities. Depending on productivity requirements, the direction of construction can be split using multiple access points

To improve excavation material management, a tower surge bin would be used to receive spoil and load semi trailers for transfer to either spoil management sites, or direct to tip sites. It is noted that if night time excavation is required to achieve program outcomes, arrangements for a 24 hour tip site would be required, or alternatively a transfer spoil site would be required if stock pile facilities at the extraction points are insufficient.

Tunnel drainage, invert slabs and centre walls can be constructed as soon as sufficient excavation has been completed to provide an unhindered work front. The same conveyor system used to remove the excavated material would also be used to transport aggregates and concrete into the tunnel (ie, top conveyor run for materials in and bottom conveyor run for materials out). Drainage pipes, reinforcement and centre wall materials would be brought in using small trucks.

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Crossings to Clayton Road and the Princess Highway could be constructed using a number of options, however the simplest approach is believed to be a continuation of the cut and cover approach. Secant Piling works would be completed in night time and weekend closures of individual lanes of these roads with piles and pile holes covered with road plates when the lanes are returned to normal traffic. Weekend lane closures would be used to excavate and install tunnel soffit slab and waterproof membrane and then resurface the road and return to traffic. Under slab excavation can then be tied into the overall under slab excavation program.

An alternative approach could be to jack in a precast structure, however this introduces a different work method which needs to be dovetailed into the more typical piling and roof slab approach and overall is believed to introduce greater complexity and risk into the construction process.

Portal locations in cut and cover are easily finished with the soffit slab finishing at the point that the tunnel roof level raises above natural ground level. At this point, the side walls then continue as cantilevered piles until either the associated ground material is able to be battered sufficiently to self support, or otherwise less expensive retaining structure can replace the cantilever pile wall. Some level of aesthetic surface finish would likely be required at this location. Finally when the tunnel invert slab rises to match natural ground level, ballasted track structure is resumed. At this location a transition slab is required between slab and ballasted track for the associated change in track stiffness.

Indicative unit costs for completed cut and cover tunnel based on the current concept using secant piling technique for the walls is $75 million per kilometre including centre wall and invert slab. Additional allowance would need to be made for drainage, services and track construction which are assumed common for the three tunnelling options considered here.

Construction rates for cut and cover tunnel are estimated at approximately 120 days per kilometre of completed tunnel. Piling works are critical in this rate being based on 7 rigs working dayshift only on the assumption that double shifting into night periods would not be acceptable to EPA and relevant stakeholders.

All other tasks follow behind the piling works at a suitable lag with production rates generally able to match or exceed the piling works, hence not adding to the overall production estimate. Road crossings would be completed independent of the main tunnel work front, sufficiently in advance to tie the main tunnel works and crossings together so that the excavation can advance on a continuous basis.

Productivity of 120 days per km equates to approximately 8 metres per day of completed tunnel. The program in Section 1 is based on 7 metres per day to completed invert slab. It should be noted that cut and cover tunnelling provides a great deal of flexibility allowing productivity to be incrementally ramped up and down by varying the number of piling rigs used, and can also be worked on multiple fronts with multiple teams.

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Upfront approvals, design, mobilisation for Cut and Cover are conservatively based at between 14 and 18 months from award of contract.

TBM Tunnel Construction A deeper vertical alignment would generally be required to contemplate a TBM tunnel design. John Holland Tunnelling has provided a detailed report on TBM tunnelling options (refer Appendix E). In summary, John Holland has assessed the most likely TBM tunnelling technology for soft ground conditions to include EPB technology and Slurry. The report details the specifics of operations for each of these machine types, as well as providing an overview of other TBM technologies including double shield gripper and mixed face TBM machines.

All TBM types require a base location to firstly launch the machine from, and then to manage materials (spoil out and construction materials in). Typical site layouts and launch box layouts for EPB and Slurry Machines are provided within Appendix E.

Portals in TBM tunnel are typically constructed through use of canopy tube arches constructed in advance of TBM completion. The arches are constructed, with surrounding finishes to the portal face constructed in either in situ or precast facing anchored into the ground behind. As with Cut and Cover Tunnel, a cantilever pile wall could then be used to continue side walls until the track alignment is sufficiently raised to match into normal ground level. Cosmetic finishes would be required at the transition points.

TBM completion or breakout requires a stabilised ground area, A canopy tube arch is a common approach to this for softer ground conditions. Beyond the Portal location, cantilevered piling or other common ground support mechanism could be used for the cutting faces leading to at grade track.

Cross tunnels are assumed at 250 metre spacing, and would be constructed in open air effectively following completion of the TBM lining installation.

John Holland have provided indicative direct costs for TBM purchase setup and launch and operation. These costs are summarised in Table 7 and Table 8.

Per EPB Machine Per Slurry MachineTBM Purchase $21,000,000 $22,000,000TBM Mobilisation to site $1,500,000 $1,500,000TBM Setup – Site Establishment

$2,500,000 $2,750,000

TBM Assembly $2,000,000 $2,250,000TBM Launch $1,000,000 $1,250,000Total Capital Outlay

$28,000,000 $29,750,000

Table 7: Purchase, Setup and Launch Costs (Upfront Costs Only)

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Comments EPB Machine Slurry MachineAmortised Upfront Costs (per km)

based on 6km twin bore tunnel

$9,333,333 $9,916,666

Segmental Lining Cost (per km)

twin bore tunnel $14,000,000 $14,000,000

Boring Cost (per km) twin bore tunnel $13,000,000 $13,500,000Cross Tunnel Construction (per km)

assumed 4 per km of twin bore tunnel

$6,000,000 $6,000,000

Tunnel Invert Slab (per km)

Cost assumed based on developed pricing for Cut and Cover Tunnel works.

$1,500,000 $1,500,000

Total Direct cost (per km)

$43,833,333 $44,916,666

Table 8: TBM Direct Purchase, Setup and Launch Costs Only

The direct costs in Table 7 and Table 8 have been based on an approximate extent of bored tunnel of 6km, which is based on the current indicative design alignment. Any variations from this length would result in some minor impact to the per km rate due to change in spread of the upfront costs for purchase, setup and launch. Impacts to the construction rate based on a significantly longer tunnel are suggested as being minor (less than $100k per km reduction), with the key impact being mainly due to the greater spread of the upfront costs.

The above costs are direct and exclude any allowance or overhead or margin. Suggested sell costs can typically be in the order of two times the direct job costs.

Additional allowance needs to be made for drainage, services and track construction which are assumed common for the three tunnelling options considered here.

Typical TBM production is 65 metres per week based on 11 x 10 hour shifts (ie. double shifted which are assumed acceptable due to the underground nature of the works). This is an average of 6 metres per shift, which is marginally less than the daily or shift rate for cut and cover tunnel.

The upfront program impacts for a TBM tunnel are significantly greater than a cut and cover tunnel solution with design, approvals, manufacture, mobilisation, setup, etc. taking typically between 2.5 and 3 years from contract award. This upfront duration would have significant impacts on the achievable completion date for the Rowville Rail Corridor.

Excavated Tunnel Construction The section of alignment to the East between Dandenong Creek and Rowville Station is expected to be through residual soils overlying inter-bedded silt and sandstones are anticipated. Depending on the combination of tunnel depth, and the extent and hardness of the underlying silt and sandstone, tunnel construction in this region could be undertaken using manual excavation techniques with excavators and road headers.

Portals in Road Header bored tunnel as with TBM tunnel can be constructed with a canopy tube arch, however unlike the TBM tunnel, the tunnel boring would likely commence at the

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portal location with canopy tubes being installed prior to the commencement of tunnel boring. Requirements for ground support outside the portal would be dealt with in the same way as for TBM tunnel (refer section above on TBM tunnelling).

Either a single arch tunnel or dual arch tunnels could be contemplated, however to minimise plant and equipment requirements, a single double track arch cross section is likely to produce greater economies of scale, allowing for larger excavation plant to be used and a single conveyor system for spoil disposal and materials supply.

The most significant issues associated with excavated tunnel construction are the consistency of the bored material, and management of water when below the water table. Based on the current Geotechnical advice, the silt and sandstones are expected to have significant weathering and fracturing providing multiple paths for water movement. The typical technique used to control water in such material is injection grouting, which is inherently unreliable when trying to perform in the face of running water during the excavation process. The alternative more effective approach is to pre grout the ground surrounding the tunnel in advance of the tunnel excavation. This approach would still leave areas of water ingress requiring management. During excavation, any water is then managed using local piping to provide a dry surface for tunnel lining works. Even with pre grouting, areas under the water table are expected to require a water proofing membrane.

Following completion of the arch and wall lining, the invert slab can be constructed. The base of the wall membrane is then tied into the invert slab which is also waterproofed with the goal of providing a complete 100% water tight seal. Nonetheless, the tunnel drainage system is also designed to pick up any water that does get through the final seal.

Costs for a single double track arch tunnel including waterproofing, shotcrete lining and invert slab are assumed similar to those for TBM bored tunnel, however depending on the extent of grouting, and the final water proof membrane and lining requirements, the costs could increase significantly, and may even result in greater costs than for TBM tunnel.

Additional allowance needs to be made for drainage, services and track construction which are assumed common for the three tunnelling options considered here.

Productivity for excavated bored tunnel is assumed similar to that for TBM Tunnel, however risks associated with soft ground stabilisation have the ability to severely impact productivity. Up front design, approvals, setup, etc. are assumed similar to cut and cover tunnel, as there is no TBM to be manufactured.

Comparison of Tunnelling Approaches The cost of cut and cover tunnelling construction in combination with the flexibility it provides in alignment design (ie. allows for much shallower tunnel construction compared to TBM or excavated bored tunnel) means that cut and cover tunnel provides a much lower risk approach to tunnelling than either of the alternatives. When this perspective is combined with the unit cost, the ability to vary/ increase production through either or both varying the number of piling rigs used, or the number of work fronts worked supports an initial view that

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cut and cover tunnelling technique provides the best overall cost and risk outcome for the construction of any below ground alignment for the Rowville railway corridor. Consequently, the program presented in Section 1 is based on a cut and cover approach.

Tunnel Services Installation of water, fire, HV and LV electrical and lighting, signalling and communications services routes through the tunnel can commence immediately following construction and cure of the floor slab in both cut and cover or bored tunnel constructions. Placement of the main services racks should be such that it will not clash with spoil conveyor or pipe systems, thus enabling unimpeded services installations.

Ideally the main services conduits and pipes should be installed in advance of track construction works to enable the tunnel to be clear behind the track construction (refer section 2.3.5) for signalling system connections, overhead traction contact wire installation (from elevated platforms operating on the completed trackworks) and negative return connections to the track.

Confined Space Considerations It is noted that all construction works within the tunnel would need to be managed as works within a confined space with air quality management being critical to ensuring the safety of workforce and visitors to the tunnel construction area.

A risk based approach should be used to manage air quality within the tunnel with mitigations applied accordingly to ensure that every person who works on or visits the site during the works is not exposed to undue risk to their health or lives. Pollutants, or causes or pollutants should be considered separately to assess their specific risk profiles, with specific and general controls being applied methodically to ensure that residual risks are reduced to levels as low as reasonably practical, and such that all relevant standards for air quality are achieved during the performance of any works on the site.

Key pollutants to the air anticipated within the tunnel and through various other parts of the site include:

Excavation Plant diesel exhaust – this product typically contains carcinogens and poses a high risk to workers within the tunnel. All vehicles and plant used within the tunnel to be fitted with catalytic scrubbers to remove carcinogenic components, thus able to reduce exposure consequence.

Dust from bulk excavation activities – generally considered a low risk as expected to be largely saturated with water already which will keep air bourn particles to a minimum. In addition, additional watering can be undertaken as required.

Dust from rock breaking and removal – this component of air born particles when in sandstone could introduce silica particles into the air, This risk can be reduced through reduction of the likelihood of exposure through use of water during breaking and excavation tasks.

In a normal outdoors site, these above risks are generally easily managed through basic PPE (masks, etc.), and use of watering mediums such as carts, boom sprays, etc. However

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with the introduction of a confined space, significant additional controls would be required. A number of controls may be applicable including but not limited to:

Respiratory PPE - All personnel who are required to work within or visit the tunnel are required to carry appropriate respiratory PPE.

Air quality monitoring undertaken on a continuous basis at various points through the tunnel and wherever people are working. Minimum quality standards to be set and if breached, either all works stopped and people evacuated, or otherwise approved respiratory gear must be worn by any person remaining in the tunnel.

Vacuum / exhaust systems used at any work face where dust is being generated, with local extraction and dispersion to locations clear of the tunnel.

Wind force fans used in a synchronised manner at tunnel access points. Air would typically be forced into the tunnel such that exhaust fumes can be firstly dispersed and diluted to acceptable levels, and then removed as quickly as possible. The fans can also be used to aid strong prevailing winds when they occur to improve cycling airflow into and through the tunnel. The third way the fans can be used is to support the work face within the tunnel, such that extracted dust and pollutants can be moved away from the work face as quickly as possible, to a point where they can be captured removed from the tunnel using vacuum exhaust systems.

11.4.4 Viaducts

Viaduct sections would be built using standard construction techniques which lend themselves to working within limited footprints like those through the Wellington Road alignment.

Substructure Piles would be constructed with piling rigs. Pile caps would be cast in-situ, followed by installation of precast pier and cross beams. The piers would be constructed from pre cast segments stacked vertically and pre-stressed downwards from the pier crosshead level, to the level of the pile cap for the foundations. Pre-stressing would be achieved with the use of high tensile steel bars, inserted into steel ducts cast into the concrete columns.

Superstructure The Superstructure would be assembled via launch trusses (using either under slung or overhead gantries) to install the segmental precast beam sections. The structure should be heavy enough to enable installation of cast in tensioning ducts, however stressing tendons could also be located on the inside wall of the hollow interior of the precast viaduct segments which would increase accuracy and ease of inspection and enable lighter weight concrete spans.

Indicative unit costs for completed viaduct structure based on the concept design is $5,000 per m2 of deck area. Based on an assumed deck width of 10 metres, that is approximately $50 million per kilometre including substructure and superstructure.

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Overhead Structures and Walkways Provision for erection of overhead structures are assumed made in the base viaduct structures with either block-outs with contained starter bar or alternatively rag bolts cast in for easy erection of these structures. Maintenance Walkways would either be designed as part of the viaduct structure, which would result in a somewhat more bulky and expensive casting, or alternatively, so that this can be installed as part of the overhead structure arrangement in steel. It is believed that this second option would provide a more cost effective outcome with better aesthetics able to be achieved due to the lighter weight and more streamlined viaduct structure, however this would need to be balanced by the design requirements to limit noise and vibration.

11.4.5 Railway Infrastructure (Tracks, Power and Signalling)

The final stage of the construction works through tunnels and stations would be the track, signalling and traction supply service installations. Conduit routes for signalling and electrical traction supply should be installed with the main tunnel services racks and conduits in advance of the final track and track services installations. Track for the Rowville line is assumed to be slab construction. Bottom up track slab construction is preferred as it provides improved tolerances in construction, and is generally quicker than top down techniques.

A track slab is constructed and levelled on top of the Invert Slab with reinforcement set using templates to provide spaces for bolt holes. Following slab cure, a separate team come through and bore and set ferules and rail plates to survey position. Rail plates provide additional adjustment to ensure tolerances are achieved.

During track slab construction, local conduits for signalling and negative traction return cabling can be allowed within the slab to minimise the extent of any exposed local cabling through the corridor.

Following through behind the track slab construction, signalling circuits, bonding and trackside signalling apparatus would be installed and connected in parallel with overhead traction system installations.

A number of options are available for overhead catenary and contact wire. In cut and cover tunnel, mounting points for the overhead traction system can either be mechanically or chemically fastened directly to the underside of the soffit slab, or side braced between tunnel wall and centre wall piles, depending on clearance allowances in the tunnel height. Bored tunnel is a little more problematic. Typically a chemical bonding approach for traction system mounting is preferred to maintain the structural integrity of the tunnel lining.

11.5 Work Sites

The horizontal alignment runs from the Down side of Huntingdale Station, out under North Road, then traverses the on and off ramps to North Road before swinging back under the West bound lane to the centre median of North Road. From here it progresses down the

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centre of North and Wellington Roads until just east of the Garnet Road intersection to Wellington Road. From this point, there are 3 options for the remainder of the alignment to Rowville:

The Golf Course North option turns to the north across the south side of the Dandenong Creek wetlands area, crosses Eastlink, wraps around the North side of Kingston Links Golf Course, then turns south east adjacent to the Stamford Estate development site, finally crossing Stud Road into Rowville station where it terminates beneath the Stud Park shopping centre.

The Golf Course South option runs further south than the option above, wrapping around the south side of the golf course, and along the north side of the Wellington Rd industrial estate before turning north up Stud Road to terminate beneath the Stud Park shopping centre.

The Wellington Road option continues along Wellington Road, then turns north into Stud Road before also terminating beneath Stud Park.

Representatives of Monash and Knox city Councils at a Constructability review on 9 September 2011 were queried about viable work sites able to be used for equipment storage, and spoil management tasks. They advised a number of possible sites along the alignments. Specifics of these sites are detailed below, and also shown in Figure 25.

1) The land to the North side of the existing Huntingdale Station owned by Victrack (approx 7,000m2) and possibly also the existing commuter carpark next to it (approx 6,000m2). This land (and carpark) are the logical place to construct the new underground station platforms from at Huntingdale, if a design can be made to fit. Otherwise, it is a premium site for equipment and materials storage and management.

1) Huntingdale North Road on and off ramps and the existing commuter carpark at the centre of the ramp loops (approximately 4,000m2). With tunnel alignment passing directly under this carpark area, it makes an ideal place to access the tunnel works for spoil removal, materials supply and equipment access. If a bored tunnel, it could also provide an ideal place to launch a TBM if this method of tunnel construction was chosen.

2) Monash University lands to the North East side of the Wellington Blackburn Roads intersection. Council believe that there are sections of land not currently used by Monash University and that some arrangement may be able to be made to use some of this. This would make a viable central site in particular for spoil and material management.

3) Private land to North East side of Nanbilla and Wellington Roads intersection – Investigation required to ascertain the owner, however site also suitable for spoil and material management.

4) Kernot Avenue Sports Fields could possibly be considered for temporary use followed by re establishment.

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5) The Mirvac Subdivision site to the South of Wellington Road off Jacksons Road could also provide a materials and spoil transfer / management site, with the added advantage that if Mirvac are open to it, the majority of environmental protection facilities are likely to already be in place.

6) Stamford Estate to the West side of Stud Road if available would provide a significant site for management of the Eastern end works, and in particular for the preferred option alignment

Figure 25: Possible Work Sites

There would no doubt be other viable locations further away from the alignment which may also provide materials storage relief. More detailed investigations will of course be required to establish the full viability of each of the above sites and others.

In addition to the above, the full extent of the centre median down North and Wellington Roads, as well as the broader station footprints where they occur would be utilised at different times during the construction process.

11.6 Traffic Management

The most prominent traffic management requirement would be that associated with cut and cover or open cut construction works in the centre median of North and Wellington Roads,

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and those in and around the Huntingdale, North Road on and off ramps. Of the two construction methods, open cut would present the greater disruption because it does not provide a platform for construction work or traffic diversions unless temporary arrangements are made.

Generally the road corridors along North, Wellington and Stud Roads provide sufficient width to allow management of temporary lane diversions, associated with cut and cover construction, albeit with lane closures. The traffic management implications of construction techniques are discussed in section 11.4.2.

Commuter parking arrangements at Huntingdale Station would require appropriate management, and depending on the final chosen alignment into Rowville Station, there could also be a sizable traffic management task on Stud Road in association with construction access and modified customer parking at Rowville Shopping Centre.

Stage specific traffic management would also be required in and around crossings to major roads (Clayton Rd, Princes Hwy, Blackburn Rd, Springvale Rd, Monash Hwy and Eastlink).

An experienced full time traffic management team should be established during the detailed design stage to develop and negotiate traffic management plans for the project with the respective local councils, VicRoads and ConnectEast (for EastLink). It is noted that the traffic management for the project would require a large amount of stakeholder engagement which would most likely require the support of either contractor or superintendents stakeholder management representatives. Specific considerations for the various zones and locations are further outlined below.

11.6.1 Huntingdale Station Precinct

The main access into and out of Huntingdale Station are from Railway Avenue off Huntingdale Road (also serviced by the North Road Ramps) on the Down Side, which is also where the majority of traffic impacts are anticipated due to use of the land and carpark on the North side of Huntingdale Station, and possibly the land in the centre of the North Road Ramps.

Additionally lesser impacts are anticipated on Haughton Ave on the Up Side due to access being used to construct the Up Main tunnel portal connection.

Agreements would be required with VicTrack and MTM as to any required station car parking areas, while agreements would be required with Monash City Council in regards to which roads can be closed, and associated alternative traffic routes.

Traffic management plans for this area would also need to make allowance for maintenance access to the existing Huntingdale station and buildings.

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11.6.2 North and Wellington Roads

The majority of tunnel and elevated structure construction, as well as construction of 3 stations (1 above ground and 2 below ground) would occur along the centre median of North and Wellington Roads. To achieve the staging of these works effectively would require a large amount of flex and movement in the construction footprint which would require various ongoing lane closures along the length of the works. Indications by Monash and Knox Councils to date suggest they are not averse to short term off peak and night time lane closures along the majority of this route, and would even accept longer term lane closures, using the bus lanes as relief.

Generally, it is expected that the lane closures would be managed by a series of warning signs in advance of the works to warn drivers with land mergers and closures protected with flagmen and jersey barriers.

Detailed stage by stage traffic management plans would be required for all sections of North and Wellington Road with lane closures fully supported by assessments of existing and impacted traffic numbers and patterns.

11.6.3 Stud Road and Rowville Station Precinct

Loss of car parking amenity and changes to traffic paths within Stud Park shopping centre car park, and onto Stud Road would be required. Traffic management plans would need to be agreed with both the relevant local council and the shop owners (or their designated representative).

Again traffic detours and lane changes would be advised through advanced signage, and flagmen where required, with closed routes and lanes protected by jersey barriers.

11.6.4 Major Road Crossings

Based on the alignments, under road crossings would be constructed at Clayton Road, and Princess Hwy, while over road crossings would be constructed at Blackburn Road, Springvale Road, Monash Freeway and East Link. Regardless of construction approach, some extent of lane or road crossings would be required to complete the works.

The under road crossings would generally require single lane closures to complete progressive piling and slab construction works. Requirements for total road closures are not currently anticipated, with the majority, or all works expected to be completed during off peak traffic flow periods. Traffic management plans for these partial road closures should be relatively straight forward to plan and agree with the respective authorities.

Over road crossings are more likely to require short duration single direction and/or full road closures to enable beam installations over the roads. These closures would be programmed to occur in off peak periods such as weekends and night. Alternative traffic routes and detours would need to be agreed with the respective road authority.

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The approach to lane closures would be the same as for North and Wellington Road lane closures with traffic controlled with signage and flagmen, while closed lanes protected with jersey barriers.

11.7 Maintenance Access Requirements

To the extent possible, the developed traffic management plans should consider the broader requirement of spoil disposal across the entire project. Various controls could be applied to minimise the impacts of trucks carrying excavated materials from site to tip:

Truck routes should be planned to use main roads with appropriate load ratings, Entry and exit points to and from roads should be aligned to match the direction of traffic

to minimise risks and impacts to road traffic. Truck movements should be metered through the day with the majority of movements

planned for off peak traffic periods Transfer stockpiles used to enable shorter but more frequent truck movements from the

site, with transfer from stockpile to tip able to be spread over a longer duration 11.8 Protection of Operational Rail Infrastructure

The current alignment has a single geographical interface with the existing operating Dandenong railway line to the Western or Up side of the existing Huntingdale Station. In addition, there would be operating interfaces at the railway connection point and at Huntingdale Station where new underground platforms need to be seamlessly integrated into the station.

The railway interface would include integration of signalling, electrical, communications systems. In addition, some allowance for temporary station facilities may also be required to facilitate redevelopment of the existing Huntingdale Station so that the new underground platforms are able to be properly interfaced with the existing above ground platforms.

Management of these interfaces through appropriate design development will be an important aspect of how the construction interface is ultimately dealt with.

In the final configuration, tunnel portal structures are anticipated on both the North (Up) and South (Down) side of the Dandenong line. The track would emerge from these portals before connecting to the Dandenong line initially at a set of new turnouts on both Dandenong up and Down tracks. It is understood that feasibility planning has been undertaken to determine future direction with quadruplication of the Dandenong line. As such, any Rowville line connection alignment should be designed to facilitate such future quadruplication works and possible replacement of the turnout connections with crossovers.

Positioning of the tunnel portals should be such that they are sufficiently clear of the operating Dandenong Line to enable brown field construction approach behind full delineation fencing, without need for safeworking protection. The goal of all civil construction works around Huntingdale Station and the Dandenong line (including all track construction

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clear of safeworking zones, conduit and pit positioning for signalling and electrical services routes, etc.) should similarly be to maintain separation from the live operating track at least until the time of railway systems connections (ie, track, signalling and overhead).

At some stage late in the construction program, a number of track occupations over the Dandenong line would be required to install final services cable routes, to reconstruct formations and drainage and install the new turnouts, and to ultimately connect new signalling and overhead tractions systems, followed by system testing and integration and commissioning into operation. A mixture of night period and weekend track occupations are expected.

All stages of construction, whether clear of operating lines, or under track occupation must be planned to protect existing infrastructure.

Maintenance of reliable station operations at Huntingdale would also provide an interesting challenge. Two concepts have been considered for new underground platforms. The first involves platforms almost directly underneath the existing Huntingdale Platforms. Constructability of any underground platforms that lie within the existing station footprint is expected to require demolition of the existing platforms, which would subsequently require an extended closure of Huntingdale with bussing transfers to other stations, or otherwise the establishment of a temporary platform elsewhere. The location for a temporary platform would be to the south side of the North Road flyover. Such temporary facilities would require significant planning, along with several Dandenong Line railway occupations to undertake the platform construction. Demountable buildings could then be erected on the temporary platform, in conjunction with temporary Pedestrian crossings which may be un-gated with signage for the temporary arrangement, however gating, or bell/ flashing light systems may also be required. An alternative option may be temporary ramps and bridges.

Another option for the underground platforms is for them to be positioned under the existing commuter carpark on the North side of the Dandenong Corridor at Huntingdale. We believe a positioning is achievable clear of the existing platform and track alignments which would enable construction of the new platforms fully clear of existing railway and station operations. Final connections would be achieved through extension of the existing under platform subways into the concourse area above the new underground platforms. Property acquisition would most likely be required. Refer to Figure 26 for an illustration.

Such a design would largely remove construction interface enabling the existing station to continue operations unaffected.

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Figure 26: Alternative Station Design Concept – Offset underground Station

11.9 Operational Requirements

During construction, it is expected that all construction areas, and supporting land areas would require full security fencing. Similarly, all access points would require proper gate arrangements supported by traffic control and security arrangements. Many sites within the project (station pit locations, portal locations, etc.) would provide points of interest for members of the public (law abiding or other). Any site that presents a higher interest risk, including fall risk, would require special attention, for example, station construction locations may warrant screening hoardings. The decision to implement higher standard protection should be determined through appropriate risk based assessments by the constructing contractor.

Of particular importance would be the station construction works at Huntingdale Station. No doubts specific path and fencing arrangements would be required here to support ongoing reliable operations at the station (if not closed), or temporary station if this option is taken up. The key goal here is protection of commuters and public.

11.10 Rail, Road and Pedestrian Protection Measures

As a general rule, road and pedestrian access to any part of the site should be discouraged through appropriate fencing and signage. Any site access locations should be gated, and security controls such as sign on books used to ensure proper control of people into and out of the site. In keeping with good site management practices, all construction personnel on the site must be inducted, and carry all required tickets and certifications. Similarly any visitors to the site must be accompanied by inducted and suitably experienced site personnel.

Soffit Slab

Existign Carpark Access Existing Platform Access

New Underground Platform and Tunnel

Station Pit Pile Walls

Existing Above Ground Platform

Existing Station Subway

Fence

Existing Street Access

Ramp from Concourse Level

Existing Subway opens to new concourse at same

Concourse Floor Slab

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During construction, in particular where there is road traffic interface, jersey or other appropriate temporary crash barriers should be installed until such time as permanent arrangements (as designed) are completed.

Permanent crash protection needs to be allowed and designed for any at risk infrastructure.

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12. Railway Operational Safety

Tracks in open-cut adjacent to heavily trafficked roads

Heavily trafficked major roads running alongside open-cut would be of particular concern regarding the hazard posed by a road traffic accident and/or insecure load and the risk of a vehicle on track or load shedding onto track.

Two options for mitigating this risk are shown in Figure 27. The one relies on providing a barrier to prevent the vehicle travelling onto the track and a space for the load shedding, the other relies on a high-containment barrier to prevent vehicle and load travelling onto the track.

Figure 27: Options for mitigating the risks posed by traffic running next to open cut railway

13. Operational Maintenance

Proportional to its length this portion of railway has a high proportion of open-cut /tunnel or viaduct with comparatively little track at-grade.

The lengths of different forms of construction would depend on the alignment chosen but typically, depending on options chosen, for this 13km length railway the lengths of different forms of construction are in the order of viaduct 5-7km; open-cut/tunnel 5-6km; and at-grade 0.5km

Civil – open cut would put a higher emphasis on effective drainage using cut-off drains and pumping depending on the level of nearby drains. Tunnels would incorporate line-sumps and pumps at low points. Viaducts would have conventional bridge drainage with down pipes possibly within piers and rodding-eye access.

Access:

On-foot access would be provided to all locations. For tunnels and the viaduct the path would be that used for emergency passenger egress.

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Vehicle access along the length of the track is not provided for tunnels and viaduct or open-cut: it would be a functional advantage alongside the at-grade section on the West side on Monash Freeway where access would be required off the main highway.

Vehicle parking would be advantageous adjacent to: emergency passenger egress / emergency services entry points for tunnel and

viaduct sections. Traction power sub-stations Signalling boxes where located at ground level Access point for hi-rail vehicles

14. Developments from Previous Report

14.1 Knox City Council report Rowville Railway Pre-Feasibility Study 2004

This report will be referred to as the Knox Report.

The comments below refer to the Knox Report heavy rail options only, and also excludes the option for heavy rail between Rowville and Glen Waverley Station (Heavy Rail Option 2).

Knox Report railway proposal:

Heavy Rail Option 1A – the ‘longer elevated’ option with 9km of viaduct. Viaduct from Huntingdale Station and across Princes Highway. Viaduct through and past Monash University and across Monash Freeway. Both options the same beyond Monash Freeway - below ground past Waverley Park then viaduct across East Link then descending below ground before Rowville returning to a viaduct about 500m West of Stud Road climbing and looping first southward then North along Stud Road.

Heavy Rail Option 1B – the ‘shorter elevated’ option with 7km of viaduct. Tunnel / open-cut from Huntingdale Station climbing to viaduct at 1400m chainage continuing as viaduct across Princes Highway descending below ground at Monash University and back to viaduct around 3200m chainage and across Monash Freeway. Both options the same beyond Monash Freeway - below ground past Waverley Park then viaduct across East Link then descending below ground before Rowville returning to a viaduct about 500m West of Stud Road climbing and looping first southward then North along Stud Road.

Features of the horizontal alignment are –

i. at Princes Highway the alignment curves North of Wellington Road into the land of Monash University before curving back to Wellington Road

ii. on the sloping ground approaching East Link the alignment curves well to the South of the Wellington Road alignment crossing the existing East Link curving back to the South edge of Wellington Road at 10,250m chainage

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iii. at around 11,250m chainage the alignment again loops to the South before

turning North along Stud Road

Knox Report gaps and limitations:

a) no information presented and possible little or no consideration of:

the track alignment at Huntingdale from the level of the existing Dandenong track to the elevated level for the viaduct proposal (Heavy Rail Option 1A)

changes required at Huntingdale Station need to integrate proposals with possible upgrades to the capacity of the

Dandenong Line. the width of various track sections (at-grade, open-cut, viaduct) and

following that its impact on the existing road lanes and road system road barrier separation requirements between track and heavily trafficked

road alongside open-cut on North Road and at-grade sections of track ventilation / smoke extraction of tunnels; access for operational

maintenance; track drainage; train power consumption and sustainability station and entrances location in relation to the catchment of the local

residential potential rail users, university students, workers at local commercial and industrial premises. The proposal to locate a station within the grounds of Monash University needs to consider the attractiveness of station use for local residents as well as University students and workers.

Station planning for integration with the local community and integration

into the various transportation modes

b) track alignment addressed in a rudimentary way and with the track gradient at several locations steeper than current requirements (2% or 1:50 max) with 1:33 used for the below ground option on North Road approaching Princes Highway; 1:30 used for the below ground option at Monash University and 1:33 used for the viaduct structure at the Wellington Road / Stud Road junction.

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15. Conclusion

This engineering report presents a variety of horizontal and vertical alignment options, and options for structure types, which have been derived during the overall Rowville Rail Study process. The Rowville Rail Study has undertaken a significant amount of stakeholder and community liaison, urban planning, high level architectural design, transport modelling and environmental and sustainability reviews. This engineering report has been developed during that process; it focuses on the engineering options which should be carried forward for further consideration at the next stage of design.

The rail connection at the Dandenong Line at Huntingdale requires the Rowville tracks to connect north of the existing station, and run towards Rowville below ground level between this connection point and North Road. This below-ground alignment minimises conflict with existing road and rail infrastructure at this location, and provides for a grade-separated rail junction between the future Rowville and existing Dandenong lines.

The Huntingdale station platforms for the Rowville line would be located below ground, and Huntingdale station would need to be substantially re-developed. The report includes an alternative option for locating the new platforms east of the existing, which provides the possibility of reducing substantially the amount of work needed to the existing station. This option would require acquisition of adjacent industrial properties.

The curve of track between Huntingdale station and North Road runs beneath the Oakleigh army barracks, which would require partial demolition. Alternatively a smaller radius curve would avoid the barracks; however this would reduce the line speed over a short distance.

Cut and cover, or in isolated locations sprayed concrete lined tunnel, is most suitable for below-ground track; the cover provides the ability to reinstate the ground above the tunnel. Open cut would, however, offer capital and operational cost savings.

The North Road central median offers a suitable route for the railway with space for an open cut structure with covered crossing points.

A bored tunnel option is provided but is not part of the preferred option due to the preference for keeping the railway as shallow as possible for station access reasons, as well as taking account of the higher costs of a bored tunnel.

A viaduct is appropriate east of Monash due to the steep and undulating ground profile, and to limit the depth below ground of stations to the east and the west. Mulgrave station would be built on this elevated structure.

Track is shown below ground in a cut and cover structure along Wellington Road east of the Monash Freeway. To retain the function of the Jacksons Road/Wellington Road right turns, the railway would cross below ground to the north verge of Wellington Road.

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The ‘Golf Course North’ approach to Rowville uses viaduct across the flood plains either side of EastLink, requires property acquisitions, and a shallow tunnel beneath Stud Road. It clashes with the planned Caribbean Business Park development.

The ‘Wellington Road’ approach to Rowville follows Wellington Road across EastLink, uses viaduct to the east of EastLink, then cut and cover tunnel for the eastern part of Wellington Road and along Stud Road. The length of rail at-grade between the viaduct and the cut and cover sections would affect the industrial service road junctions along Wellington Road. Some commercial property acquisition would be required.

The choice of the alignment into Rowville will depend on factors including the consideration of property acquisitions and the loss of natural habitat.

The structures (ie tunnels, viaducts etc) needed to provide a suitable rail profile have been discussed in detail, and based on engineering assessment the cut and cover method for shallow tunnels is generally the most appropriate. Sprayed concrete lined tunnel may be effective for crossings under existing roads to limit the need for lane closures; open cut structure is also an option. Two lengths of viaduct structure are included, with one containing Mulgrave station. The viaducts provide for a smooth rail profile above undulating ground along Wellington Road, and allow the rail to be raised above the flood level for the Golf Course North option on the approach to Rowville.

The construction aspects of the scheme will be an important element given the potential for disruption during the construction phase. Cut and cover construction is feasible for the below ground track, and placing the cover before completing excavation in a ‘top-down’ approach reduces the amount of open excavation. This is a significant scheme and the anticipated project timeline for construction works is approximately three years, with a further year for rail works and rail systems commissioning.

rowville rail study preliminary rail design report final

Documents

broader report

final submissions report

design issues

design brief

basis of design

elevated station design

typical design elements

heavy rail line