carpark design guide

iEconomical CarparksA Design Guide - 2nd Edition

Economical Carparks

A Design Guide2nd Edition

Published by:

OneSteel Market Mills

November 2004

ii Economical CarparksA Design Guide - 2nd Edition

CONTENTS

FOREWORD ........................................................ iii

1. INTRODUCTION ............................................. 1

1.1 Steel Carparks ........................................ 1

1.2 Layouts ................................................... 2

1.2.1 Column Location ............................ 2

1.2.2 Headroom....................................... 3

1.2.3 Ramps & Circulation ....................... 3

1.2.4 Gradients (Excluding Ramps) ......... 3

1.3 Parking Modules .................................... 4

1.3.1 Single Module Schemes ................. 5

1.3.2 Multiple Module Schemes .............. 6

1.3.3 Carpark Space Utilisation

Efficiency ........................................ 6

2. CARPARK SCHEMES AND COSTING .......... 7

2.1 Schemes ................................................. 7

2.2 Costing .................................................. 10

2.3 Engineering Drawings ......................... 10

3. DESIGN EXAMPLES .................................... 27

3.1 Example 1 ............................................. 29

3.2 Example 2 ............................................. 30

APPENDICES

A. STRUCTURAL DESIGN CRITERIA .............. 32

A.1 Building Regulations .............................. 32

A.2 Design Loads ......................................... 32

A.3 Floors ..................................................... 32

A.4 Columns ................................................. 34

A.5 Lateral Load Resisting Systems ............. 35

A.6 Stairs ...................................................... 35

B. DURABILITY ................................................. 36

B.1 Slabs ...................................................... 36

B.2 Profiled Steel Sheeting ........................... 36

B.3 Structural Steelwork ............................... 37

B.4 Monitoring .............................................. 38

C. FIRE RESISTANCE REQUIREMENTS ......... 40

C.1 Open-deck or Sprinklered Carparks ....... 40

C.2 Not Open-deck and Not Sprinklered

Carparks ................................................ 40

D. COSTING ...................................................... 41

D.1 Methodology .......................................... 41

D.2 Costs ...................................................... 41

D.3 Different Surface Treatment Systems .... 43

D.4 Penetrations ........................................... 43

D.5 Column Splices ...................................... 43

E. SURVEY OF EXISTING CARPARKS............ 45

F. EXAMPLES OF RAMP

CONFIGURATIONS ...................................... 52

iiiEconomical CarparksA Design Guide - 2nd Edition

FOREWORD

In 1998, BHP Integrated Steel published the First

Edition of Economical Carparks A Design Guide.

Since its release countless developers and

designers have utilised the publication to assist in

the design and construction of carparks. Over the

last seven years there have been some significant

changes in design, construction techniques and in

supply of the materials required to construct these

carparks.

This Edition of the Design Guide is now published

by OneSteel Market Mills who are the largest

manufacturer of the structural steel beams

referenced in this Guide. The standard base

material for the decking profiles have changed, as

has the number of different decking profiles

available. The Australian Design Standards have

also changed making it necessary to amend some

of the design drawings. Also two new schemes

offering column free parking spaces have been

included in this Edition taking the total number of

schemes to eleven.

This Edition includes the aforementioned changes

as well as a new layout adopted to reflect the

comments made by the users of the First Edition.

OneSteel Market Mills wishes to thank the many

people who have contributed to the production of

the First Edition and this Second Edition, in

particular:

Ian Bennetts

Chong Chee Goh

John Cottam

Spiros Dallas

Anthony Ng

Nick van der Kreek

Imran Saeed

Ken Watson

Gary Yum

iv Economical CarparksA Design Guide - 2nd Edition

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1Economical CarparksA Design Guide - 2nd Edition

1. INTRODUCTION

This Design Guide has been prepared to assistengineers, architects, quantity surveyors, buildersand developers produce and cost preliminarydesigns for steel carparks.

Eleven carpark schemes utilising re-entrant profiledsteel decking on structural steel are presented withextensive information given for each schemeincluding:

slab details; beam and column sizes; number of shear connectors; connection details; corrosion protection details; and cost indicators

These schemes can be used to produce designsfor most carpark building layouts. Over the last twoyears there have been a number of new profiledsteel decks launched into the Australian marketwhich has provided many new alternative layouts.Nonetheless the schemes presented in this Guideprovide an excellent starting point for the preliminarydesign, which may then be fine-tuned as requiredand in some cases, utilise the new profiled steeldecks.

The use of the above information is illustrated bymeans of some worked examples, demonstratingsome of the advantages associated with steelconstruction for carpark buildings.

The Appendices in this Design Guide give thedetailed structural design criteria adopted for designsolutions, information on designing for durability,costing data, a survey of existing carparks andexamples of ramp configurations.

1.1 Steel Carparks

Since 1985 well in excess of 100 carparks havebeen constructed in Australia and New Zealandusing structural steelwork. Advantages associatedwith steel carpark construction include:

Earlier Occupation: Repetition from bay to bay andfloor to floor leads to reduced time in the productionof shop drawings, fabrication of connections andthe erection of steelwork. The time-savings offeredby a steel solution results in reduced financialholding costs and hence provides an earlier returnon investment.

Reduced Exposure to on-site risks: Off-sitefabrication reduces the on-site labour, whichreduces the cost of amenities and the amount ofon-site supervision. The reduction in the on-siteworkforce, delays due to weather and the on-sitecongestion reduces the exposure to on-site risk.

Greater Space Utilisation: The sizes of steelcolumns are small compared with other forms ofcarpark construction and this results in a morefunctional carpark. The column free space offeredby the long spanning capability of structural steelreduces the number of columns required and insome of the schemes eliminates all internalcolumns.

Future Proof Investment: Columns are easilystrengthened and additional connections can be sitewelded to the existing steel structure providingflexibility for vertical or horizontal extension.

Reduced Foundation Costs: The reduced deadload associated with structural steel results insmaller foundations.

2 Economical CarparksA Design Guide - 2nd Edition

1.2 Layouts

The Australian/New Zealand StandardAS/NZS 2890.1:2004 provides guidance andminimum requirements for the design and layout ofoff-street parking facilities including multi-storeycarparks. It classifies car parking facilities accordingto the type of use as shown in Table 1. Parkingspace and aisle widths are also given for each class.The nominal length of a parking space is 5.4m.

The following discussion covers some of the majorrequirements of the code which have a significantimpact on the design of a multi-storey carpark.

1.2.1 Column Location

The location of the columns is one of the mostcritical decisions in achieving an economical andfunctional carpark.

Construction using large clear spans offers thefollowing benefits:

improved visibility; increased interior lighting efficiency; ease of cleaning and maintenance; better security; and greater number of cars per unit area of available

floor space.

User Class Examples of Uses Space Width Aisle Width (m)(m) (Parking at 90o)

1 Generally all day parking 2.4 6.2e.g. tenant, employee and commuterparking, universities

1A Residential, domestic and employee parking 2.4 5.8- 3 point turn entry & exit

2 Generally medium term parking 2.5 5.8e.g. long term city and town parking, sportsfacilities, entertainment centres, hotels,motels, airport visitors

3 Generally short term city and town centre 2.6 5.8parking, shopping centres, hospitals andmedical centres

3A Short term, high turnover parking generally 2.6 6.6at shopping centres 2.7 6.2

4 Parking for people with disabilities 2.4 5.8(+ 2.4 Shared area)

Table 1 - Carpark Classifications and Dimensions


Where clear span construction is not practical, thecolumns should be carefully located so as to causeminimal interference with traffic circulation, parkingmanoeuvres and driver visibility. Figure 1 gives thedesign envelope around a parked vehicle whichshows a shaded area where columns, walls andother obstructions should be placed.

1.2.2 Headroom

The minimum height clearance for cars and lightvans is 2.2m. Car spaces for people with disabilitiesrequire a clearance of 2.3m from the carparkentrance/exit to their designated space and 2.5mabove the designated car space.

With a steel carpark, sprinklers, lights, etc. can beplaced within the depth of the steel beams. Thisnot only protects these items, but also means thatthese items do not control the floor-to-floor height.Therefore the critical height clearance dimensionis to the bottom of the steel beams.

1.2.3 Ramps & Circulation

Ramps play a major role in the efficient circulationof traffic through a carpark allowing traffic to flowfrom one level to the next. Ramps can be designedin various configurations to facilitate the requiredcirculation of traffic. A typical example of a ramparrangement and circulation for a split systemcarpark is shown in Figure 2. Additional commonramp configurations for both one-way and two-waytraffic flow are presented in Appendix F.

The Australian/New Zealand StandardAS/NZS 2890.1:2004, Clause 2.5.3 provides detailson allowable gradients on ramps. For straight rampsin public carparks, not part of a parking module,from one level to the next the maximum gradient is:

Ramps longer than 20m - 1 in 6Ramps up to 20m - 1 in 5

For further details refer to Clause 2.5.3 ofAS/NZS 2890.1:2004.

Figure 1 - Design Envelope,AS/NZS 2890.1:2004

One-way ramps should be at least 3m wide betweenkerbs, while two-way ramps should be a minimumof 5.5m between kerbs. For minimum width of rampson curve refer to Clause 2.5.2(b) of AS/NZS2890.1:2004.

1.2.4 Gradients (Excluding Ramps)The maximum gradient within a parking module is:

Measured parallel to the angle ofparking - 1 in 20Measured in any other direction - 1 in 16

Parking spaces for people with disabilities themaximum gradient should not exceed - 1 in 40

The minimum recommended gradients to allow thefloor to drain adequately are:

Outdoor area floor - 1 in 100Covered area floor - 1 in 200

Figure 2 - Example of a Ramp Arrangementand Circulation

Dimensions in Millimetres

Space width from Table 1300 300

300

900

550

1900

1000

750

50 50

200 200

300 300

5400

Close end of space


1.3 Parking Modules

A parking module is defined in AS/NZS 2890.1:2004as a parking aisle together with a single row ofparking spaces on one or both sides. In thisdocument only parking on both sides of the aisle isconsidered. The parking module excludes anyramps or circulation roadways which take off withinthe module.

Many variations could be developed for the differentclasses of carpark to cover all situations. In thisdocument, a user Class 3 module for parking at thepreferred angle of 90o to the aisle is considered.The standard module in this publication consistsof:

Parking space width 2.6mParking space length 5.4mAisle width 5.8mParking module length 16.6m (2x5.4 + 5.8)

This configuration is considered to cover mostpractical cases, and allows the designs and costsgiven in Section 2 to be quickly and accuratelyadopted at an early stage of a project. It is notedthat the new Class 3A in the latest edition ofAS/NZS 2890.1:2004 exceeds the dimensions ofthis adopted module, and the designs should beadjusted accordingly. As the design progresses, thebeams and columns would of course be designedfor the actual layout of the project. The costs persquare metre are generally not very sensitive tosmall changes in dimensions.

The other major simplifying assumption is astandard allowance for a column width of 300mm.Whilst this is usually adequate, a small number ofcolumns exceed this dimension at the bottom of aneight level carpark and this would need to beallowed for in the final design. Alternatively, thecolumns could be redesigned to fit within the 300mmwidth.

SCHEME NUMBER

Module Type Scheme Description Bay Width

2 car 3 car 4 car 5 car

SINGLE Internal and edge columns, - S1A S1B S1CFigure 3(a)

Internal columns and cantilever edges - S2 - -Figure 3(b)

Clear span with edge columns, S3A S3B S3C -Figure 3(c)

MULTIPLE Internal and edge columns, - S4A S4B S4CFigure 5(a)

Internal columns and cantilever edges - S5 - -Figure 5(b)

Note: Refer to Section 2 for full details of each of the schemes.

Table 2 - Carpark Schemes


Carpark layouts can be divided into single and

multiple module designs:

1.3.1 Single Module Schemes

Three different single module schemes have been

developed, viz:

Scheme S1 - Internal columns with edge columns,

see Figure 3(a);

Scheme S2 - Internal columns with cantilevers,

see Figure 3(b); and

Scheme S3 - Clear span with edge columns,

see Figure 3(c).

These schemes were developed for various bay

widths as shown in Table 2.

A carpark may consist of a number of single

modules as shown in Figure 4, each module

consisting of an aisle and a row of parking each

side. These modules can either be horizontal; see

Figure 4(a), or sloped to form a long ramp between

the different levels; see Figure 4(b) & 4(c). The

single modules provide considerable flexibility in

achieving different layouts.

Figure 4 - Single Module Carpark CombinationsFigure 3 - Single Module Schemes

(a) Scheme S1

(b) Scheme S2

(c) Scheme S3

Aisle

16600mm, Single Module16600mm, Single Module

Bay Width

(a) Horizontal Floor - 2 x Single Module Carpark

16600mm, Single ModuleBay Width

(b) Sloping Floor - 2 x Single Module Carpark

(c) Sloping Floor - 3 x Single Module Carpark

16600mm, Single ModuleBay Width


1.3.2 Multiple Module Schemes

Multiple module schemes are used when there area number of aisles in the same plane. They areoften used at shopping centres, hospitals andeducational institutions where the carparks arerelatively large in plan compared to their height.

Two different multiple module schemes have beendeveloped viz:

Scheme S4 - Internal columns with edge columns,see Figure 5(a); and

Scheme S5 - Internal columns with cantilevers,see Figure 5(b).

1.3.3 Carpark Space Utilisation Efficiency

Table 3 gives the square metres per car spacetogether with their relative module efficiency, foreach of the schemes. It can be seen that SchemesS3A, S3B and S3C provide up to 4% more carspace in a given area. This is the most efficientscheme as the columns do not impinge on thedesign envelope (see Figure 1).

Reference

Standards Australia/Standards New Zealand 2004,AS/NZS 2890.1:2004 Parking facilities - Off-streetcar parking, SAI/Standards New Zealand, Sydney/Wellington

Figure 5 - Multiple Module Schemes

Scheme Square metres Relative moduleper car space efficiency

S1A 22.4 96%S1B 22.2 97%S1C 22.1 98%S2 22.4 96%

S3A 21.6 100%S3B 21.6 100%S3C 21.6 100%S4A 22.4 96%S4B 22.2 97%S4C 22.1 98%S5 22.4 96%

Table 3 - Relative Layout Efficiency OfDifferent Schemes

(a) Scheme S4

AisleAisle

16600mm ModuleNext Module

(b) Scheme S5


2. CARPARK SCHEMES ANDCOSTING

2.1 Schemes

Eleven carpark schemes, as shown in Figure 6,have been designed and costed. The engineeringdrawings for each of thses schemes are given inSection 2.3.


SCHEME 2: SINGLE MODULE - CANTILEVER

Scheme S1B: 4 car spaces per module widthRefer to Drawing 1B (page 12)

Figure 6 - The Eleven Carpark Schemes(Contd. on next page)

SCHEME 1: SINGLE MODULE

Scheme S1A: 3 car spaces per module widthRefer to Drawing 1A (page 11)

Scheme S1C: 5 car spaces per module widthRefer to Drawing 1C (page 13)

Scheme S2: 3 car spaces per module widthRefer to Drawing 2 (page 14)


SCHEME 3: SINGLE MODULE







Scheme S5: 3 car spaces per module widthRefer to Drawing 5 (page 21)

Figure 6 (Contd.) - The Eleven CarparkSchemes

SCHEME 4: MULTIPLE MODULE SCHEME 5: MULTIPLE MODULE - CANTILEVER


Scheme Description Floor Costs Column Costs TOTAL COST (Floor and Columns)$/m2 $/m2 for No. of Storeys $/m2 for No. of Storeys

Beams Decking Slab TOTAL 2 4 6 8 2 4 6 8

SINGLE MODULES

S1A 3 Spaces/Bay 83 40 55 178 12 15 17 19 190 193 195 197

S1B 4 Spaces/Bay 81 40 55 176 9 12 15 17 185 188 191 193

S1C 5 Spaces/Bay 101 40 55 195 9 12 14 17 204 207 209 212

S2 Cantilever 3 Spaces/Bay 94 40 55 189 10 11 12 15 199 200 201 204

S3A 2 Spaces/Bay 73 49 58 180 22 19 24 25 202 199 204 205

S3B 3 Spaces/Bay 132 40 55 226 8 10 12 14 234 237 239 240

S3C 4 Spaces/Bay 135 40 55 230 7 9 10 13 237 239 240 243

MULTIPLE MODULES

S4A 3 Spaces/Bay 84 39 55 177 9 12 15 19 187 190 192 196

S4B 4 Spaces/Bay 80 39 55 174 8 11 15 18 182 185 189 192

S4C 5 Spaces/Bay 97 39 55 191 8 10 14 16 199 201 205 207

S5 Cantilever 3 Spaces/Bay 87 39 55 181 9 10 12 15 190 191 193 195

2.2 Costing

The cost of each of the eleven schemes has beencalculated on a square metre rate for 2, 4, 6 and 8storey high carparks. The results are presented inTable 4.

The costing has been done on the basis of usingBONDEK profiled steel decking.

Table 4 - Cost Summary

2.3 Engineering Drawings

The schemes have been designed in accordancewith the criteria given in Appendix A.

Notes:1. The values in the table have been rounded to the nearest dollar prior to totalling2. Costs for all schemes are based on the use of the coating system specified in Table B2 for the Atmospheric Corrosivity Category C

24 Economical Carparks A Design Guide 2nd Edition


3. DESIGN EXAMPLES

Figures 6(a) & (b) show flowcharts outlining thetypical steps involved in arriving at suitablepreliminary design and costing.

Two design examples are provided in this Sectionto illustrate how the information in this Design Guidemay be used.


Figure 6(a) - Flow Chart for Design Figure 6(b) - Flow Chart for Costing

* Note: Refer to Appendix C, Section C1 for a definition of open-deck carpark

Is it astand alone

open-deck* orsprinklered*carpark?

Is it asingle

module?

SchemesS1A, S1B, S1C


SchemeS2


SchemeS5

Arethere edgecolumns?

Arethere edgecolumns?

Arethere internalcolumns?

STEP 1

STEP 2

STEP 3

STEP 3a

STEP 4

YES

NO

NOYES

YES YESNO NO

YES NO

Select appropriate drawing provided in Section 2.3. For Schemes S1, S3 and S4the final selection is also based on spaces/bay requirementsSTEP 5

Refer to Appendix C, Section C2Then use the appropriatesections of the guide & if requireddetermine extent of fire protection

Use Table 4 to pricethe schemeSTEP 6

STEP 7

STEP 8

Adjust price forpenetration andsurface treatment

(use Tables D2 & D3)and for Fire

Protection if required

Design and costother elements


Preliminary costing (see flow chart in Figure 6b):

STEP 6 The cost of 8 suspended levels is obtained from Table 4.A scheme may be selected on the basis of cost and/or preferredlayout. Scheme selected in STEP 5 may be revised if cost is thedeciding issue.In this case Scheme S4B currently chosen is found to be economical.

STEP 7 Adjust base cost determined in STEP 6 using data from Appendix DAdjustment for surface treatment (Table D2)Adjustment for beam penetrations (Table D3)Calculate Net Adjustment (Price from STEP 6 + Adjustments)

STEP 8 Design and cost all other elements not covered in this Guide, e.g.stairs, ramps, lateral bracing systems.

3.1 Example 1

Project Name: Carpark Design Guide Job No: CDG1Subject: EXAMPLE 1 Page: 2/2Designed: AN Date: 1/10/98

C2

PB2C1

PB1

C1

PB1

C1

PB1

C1

PB2

C2

PB2PB1PB1PB1

B2B1B1B1B1B1B1B1B1B1B1

C2 C2C1C1C1C1

PB2

B1B2

Secondary Beams

Primary Beams

B2

PB2B1

PB1Mark Camber

45mm360UB44.7 -

360UB50.7360UB50.7

530UB82.0Size

26

36- ncu

50mm

20 mmStuds

310UC118350WC1973 & 4

5 & 6

Level Column C1 Column C27 & 8

1 & 2

200UC59.5

350WC230

150UC37.2200UC59.5250UC89.5310UC118

Mod

uleWidth

33200mm4150mm 8300mm 8300mm 8300mm 4150mm

ncu - natural camber up

The figure above shows diagrammatically the architects requirements for an8 storey carpark.

The carpark is to be open deck. The surface treatment to be appropriate for atmospheric Category C. No penetrations in primary beams required. Edge columns are permitted.

Preliminary design (see flow chart in Figure 6a):

STEP 1 Is this an open deck carpark - YesSTEP 2 Is this a single module? - No (2 x 16600 = 33200)STEP 3 Are there edge columns? - YesSTEP 4 Possible schemes S4A, S4B and S4CSTEP 5 Based on the information given in the Scheme S4B drawing, the

following design information is relevant.


Design Constraints

33.2m 60m




A developer requires a carpark to suit the following criteria:- 4 suspended levels. Site is 34m x 75m with 3% fall across the 34m. Facade to be out of light weight steel up to barrier height only open deck

carpark. Surface treatment to be appropriate for atmospheric Category C with top coat

varying in colour for each floor. 1 circular penetration per primary beam.

Preliminary design (see flow chart in Figure 6a)

STEP 1 Is it an open deck carpark?Yes, a requirement of the developer.

STEP 2 Is it a single module carpark?Since it is 34m wide it could be 2 single modules with a split level ora multiple module of 2. Since a split level carpark will suit the 3% fallacross the site and also will result in shorter ramps which will notintrude into the aisle width, adopt the single module option.

STEP 3 Are edge columns allowed?There is no requirement that the edge beams are to be cantilevered,therefore use scheme with edge columns. Table 4 indicates edgecolumns result in a more economical structure.

STEP 3a Are internal columns allowed?Again there are no requirements set. Table 4 indicates that schemeswith internal columns are more economical.

However if maximum flexibility is desired then no internal columnswould be the preferred option. In this example we are looking for themost economical option therefore the internal column schemes willbe considered.

STEP 4 Schemes S1A, S1B and S1C are therefore appropriate.

STEP 5 Design as a 4 suspended level carpark. Refer to drawings 1B, C1and S1.

3.2 Example 2

Design Constraints

NaturalGround3% fall




STEP 5 Columns for a 4 level carpark.(Contd.)

The table on drawing 1B gives column sizes for an 8 level carpark.For a 4 level carpark use the column sizes for the top 4 levels.

For the C2a which is normally an external column for single modulecarpark, use the same size as an internal column, ie C1.

This gives:

250UC89.5200UC46.23

2

Level ColumnC1/C2a

ColumnC2

1

4

250UC89.5

200UC46.2

200UC59.5200UC59.5150UC37.2150UC37.2

The 10.7m bays can be repeated 7 times.

Preliminary costing (see flow chart in Figure 6b):

STEP 6 The cost of a scheme is obtained from Table 4

STEP 7 Adjust base cost using information from Appendix D (Table D2 forsurface coating and Table D3 for penetrations)

(a) Surface Treatment - Category C plus top coat (Table D2)(b) 1 circular penetration per primary beam (Table D3).

STEP 8 Design and cost all other elements not covered in this Guide, e.g.stairs, ramps, lateral bracing systems etc.

L4.5L3.5L2.5L1.5

GROUND

L4L3L2L1

GROUND NATURALGROUNDC2 C1 C1

C2a C1 C1 C2

C2 C1 C1 C2a

C1 C1 C2C2C2 C1 C1 C2a C1 C1

B1 B1 B1 B1 B1 2/B1 B1 B1 B1 B1 B1 B2B2

PB1 PB2 PB2 PB1 PB2PB2

PB2 PB1 PB2 PB2 PB1 PB210

700m

m

16600mm 16600mm

Mark Size Studs CamberPrimary Beams PB1 460UB82.1 36 20 mm

Secondary Beams B1 360UB50.7 26 50mmPB2 410UB53.7 - ncu

B2 360UB44.7 - 45mm

Mod

uleWidth

ncu - natural camber up


A. STRUCTURAL DESIGN CRITERIA

The following principles guided the selection of thestructural systems given in this publication for thevarious schemes.

Simple details were adopted wherever possible tominimise fabrication costs and to allow fast erectionof the steelwork on-site.

A.1 Building Regulations

The modular carpark designs given in thispublication comply with the provisions of theBuilding Code of Australia (Australian Building CodeBoard, 2004) for stand alone open-deck and closedcarparks with sprinklers. The companion to thisdocument Economical Carparks - A Guide to FireSafety (Bennetts, Poh & Thomas, 2001) explainsthe fire protection requirements in more detail forboth stand alone carparks as well as carparks withinmixed occupancy buildings.

A.2 Design Loads

The carparks have been designed for the followingloads:

Superimposed dead loads - 0.1 kPaLive load - AS/NZS 1170.1:2002 - 2.5 kPa(with no reduction for tributary area)

A lightweight self-supporting steel facade andguardrail have been assumed to exist along theperimeter of the carpark. If a concrete or other heavyfacade is adopted, the edge beams and supportingcolumns will need to be designed for the heavierloads.

A.3 Floors

A.3.1 Use of Unpropped Construction

It is preferable not to prop the beams or slabs forspeed of construction, to keep an open workingspace and also to minimise concrete crackingproblems. Hence, for all cases except Scheme S3A,secondary beams are spaced at about 2.8mcentres. This spacing was considered to correspondto the maximum spanning distance for 1.0mm re-entrant profiled steel sheeting (continuous over aminimum of three spans) to achieve aestheticallyacceptable deflections. Alternative sheeting profilescan be used in accordance with A.3.3.

With Scheme S3A, where the beams are spacedat 5.2m centres, it was not considered economicalto provide intermediate secondary beams. So forthis case only, the profiled steel sheeting (0.75mmBondek) is propped during construction.

A.3.2 Beams

The beams were designed to AS 2327.1-2003 andAS 4100-1998. The beams are cambered for theweight of the wet concrete, except when the camberis less than the straightness tolerance specified inAS 4100 (lesser of length/1000 and 10mm).Vibration in the carparks that have been constructedpreviously has not been identified as a problem andthis was confirmed in checks carried out using themethods proposed by Murray, Allen & Ungar (1997).

The limit state design models proposed by Hogan& Thomas (1994) were generally adopted for thedesign of connections. The number of bolts is oftenless than that given in the third edition of the AISCStandardised Structural Connections (Australian

Appendix A


Institute of Steel Construction, 1985), which wasbased on the working stress steel code, AS 1250-1981. 8mm steel flat was adopted as the standardweb-side-plate in order to avoid the need to stockplates of different thickness. Dimensions such asedge distances, bolt size and pitch are generally inaccordance with the recommendations by Hogan& Thomas (1994).

The primary beams have been checked inaccordance with Chick, Dayawansa & Patrick(1998) for a 200mm diameter unstiffened circularweb penetration. Larger penetrations, eitherunstiffened or stiffened, and end notches can beprovided, but would need to be designed. Pipesshould be designed to run under or between thesecondary beams.

A.3.3 Profiled Steel Sheeting

The designs in this guide have been developed forBondek, which satisfies the design criteria set outin Figure A1. Other re-entrant sheeting profilesconforming to AS 2327.1-2003, such as CondeckHP, KF57, RF55 may be used provided thesecriteria are satisfied, and any other effects that thismay have on the building design are taken intoaccount - e.g. beam size and spacing, shear studnumbers and spacing, thickness of slab, etc.

Over the last two years three new types of steeldecks have been introduced into the Australianmarket, which are commonly described astrapezoidal decks. These decks are not coveredby AS 2327.1-2003 and are subsequently notutilised in the 11 carpark schemes presented in thisGuide. However, literature published by themanufacturers of these decks indicates that theyprovide a competitive alternative to the re-entrantprofiles steel sheeting considered in this Guide. As

The criteria listed in this figure were adopted for the design ofthe profiled steel sheeting acting as formwork. Bondek with anominal base metal thickness of 1.0 mm is satisfactory for thelargest beam spacing involving unpropped construction, i.e.2.8 metres. Condeck HP and other profiled steel sheetingproducts may also be considered for use, provided a CertifiedStructural Engineer confirms that these criteria have been met.

1. The minimum nominal loads for construction comply withAppendix F of AS 2327.1-2003, viz.:

(a) Construction Stage 1 (See Notes):1.2 G

sh + 1.5 Q

U

where QU= 1.0 kPa; OR

1.2 Gsh

+ 1.5 QP

where QP= 1.0 kN in edge pan or

2.0 kN elsewhere.

(b) Construction Stage 2:1.2 (G

sh + G

reo ) + 1.5 Q

M

where QM= 5.0 kPa; OR

1.2 Gsh

+ 1.5 QP

where QP= 1.0 kN in edge pan or

2.0 kN elsewhere.

(c) Construction Stage 3:1.2 (G

sh + G

reo + G

conc) + 1.5 Q

U

where QU

= 1.0 kPa; OR1.2 (G

sh + G

reo + G

conc) + 1.5 Q

Heap

where QHeap

= 2.0 kPa over1.6mx1.6m.

2. The maximum deflection of the sheeting does not exceedspan/200 under the dead loads (G

sh + G

reo + G

conc)

corresponding to Construction Stage 3.

3. The strength and stiffness of the profiled steel sheeting areassessed using recognised procedures supported byadequate test data. If further information is required contactdeck suppliers.

Notes:G

conc= dead load of concrete including ponding;

Greo

= dead load of steel reinforcement;G

sh= dead load of steel sheeting;

QHeap

= heaped-concrete live load;Q

P= point live load; and

QU, Q

M= uniformly-distributed live load.

Figure A1 - Profiled Steel Sheeting Design

these trapezoidal decks are not covered by anAustralian Standard, designers are left with theoption to use the respective manufacturersrecommendations or an International Standard withdesign to engineering principles, or a combinationof these.

A.3.4 Slabs

The composite slabs have been designed using apartial shear connection strength theory(BlueScope, 2003). Grade 500PLUS reinforcingbars have been adopted in lieu of mesh as this isbelieved to be more economical. In addition, nospecial details are required to avoid overlappinglayers of mesh. It should be noted that Scheme S3A

utilises moment redistribution, while AS 3600-2001permits the redistribution of moments with gradeN500 bars but not with cold-reduced mesh.Therefore the bar reinforcement specified on thedrawings in Section 2.3 cannot be directlysubstituted with mesh of equivalent area.

Scheme S3A has been designed as simplysupported for the strength limit state, with crackwidth and deflection checked at serviceability loadlevels. All the other schemes have been designedfor the bending moments and shear derived froman elastic analysis.

Reinforcement intensity is typically 6.5-7.5 kg/m2

for each of the 11 schemes contained in this Guide.


Refer to Appendix B on durability for details ofshrinkage-and-temperature and other crack-controlreinforcement.

A.4 Columns

The columns have been designed in accordancewith AS 4100-1998. Allowance has been made forpattern loading and a maximum floor-to-floor heightof 3m when determining their size.

The columns have been designed for the verticalloads of an eight level carpark. The designs can beused for carparks with fewer levels by using sizecorresponding to the top levels e.g. for a two levelcarpark, the appropriate columns are those requiredfor levels 7 and 8. Whilst the column size is givenin increments of 2 levels, it may be more economicalin some cases to remove the column splice(s) andrun the heavier column all the way up. The practicallimit for this approach is 6 levels. This is discussedin more detail in D.5.

The column splices have been incorporated in thedepth of the slab for aesthetic and functionalreasons.

Edge columns in single module schemes have onlybeen designed for that situation. Where twomodules abut (for example combination singlemodules - see Figure 4 - for Scheme S1A, S1B &S1C) the columns common to two modules taketwice the vertical load. These columns can beconservatively designed as internal columns.

Figure A2 - Steel Stair Options

TYPICAL STAIR CONFIGURATION

125

125

STAIR TREAD OPTIONS

TubularHandrail

Support Landingon Steelwork orHang from above

Stringer200x100 Flat or200PFC

5mm Pressed PlateFill with Concrete

40 Typ.

40 Typ.

6mm PressedFloor Plate

Pressed SteelPlate ConcreteFilled

PressedSteel Plate


A.5 Lateral Load Resisting Systems

The designs in this Guide only cover verticalloadings. Lateral load-resisting systems can utiliseramps, shear walls and steel moment or bracedframes. Generally, braced frames are moreeconomical than moment frames. Braced framescan be located along the perimeter of a carpark oralong the column lines.

A.6 Stairs

To match the speed of construction offered by steel,it is common practice to adopt steel stair systems.These fall into two categories viz.:

Formwork systems such as Stairmetal Formwork

(Aus Iron Industries Pty Ltd, Melbourne -http://www.ausironindustries.com.au).

Steel stairs as shown in Figure A2. These allow

safe access to all floors during construction, aswell as providing permanent access. They areoften fully assembled in the fabrication shop andlifted directly into place on site.

References

Australian Building Code Board 2004, BuildingCode of Australia, Volume 1: Class 2 to Class 9Buildings, ABCB, Canberra

Australian Institute of Steel Construction 1985, AISCStandardized Structural Connections, 3rd edn, AISC,North Sydney

Bennetts, I. D., Poh, K. W. & Thomas, I. R. 2001,Economical Carparks - A Guide to Fire Safety,OneSteel Market Mills, Newcastle, Available: http:/

/www.onesteel.com/productspecs.asp?specID=54

BlueScope Steel 2003, Using BONDEK - Design &Construction Guide, BlueScope Steel Limited,Available: http://www.bluescopesteel.com.au(registration required)

Chick, C. G., Dayawansa, P. H. & Patrick, M. 1998,Structural Design of Simply-supported CompositeBeams with Large Steel Web Penetrations,Australasian Structural Engineering Conference,Auckland, New Zealand, pp. 159-166

Hogan, T. J. & Thomas, I. R. 1994, Design ofStructural Connections, 4th edn, Australian Instituteof Steel Construction, North Sydney

Murray, T. M., Allen, D. E. & Ungar, E. E. 1997, FloorVibrations due to Human Activity, Steel ConstructionGuide Series 11, AISC/CISC, Chicago

Standards Australia 1981, AS 1250-1981(superceded) SAA Structural Steel Code, SAI,Sydney

Standards Australia 2003, AS 2327.1-2003Composite structures - Simply supported beams,SAI, Sydney

Standards Australia 2001, AS 3600-2001 Concretestructures, SAI, Sydney

Standards Australia 1998, AS 4100-1998 Steelstructures, SAI, Sydney


B. DURABILITY

B.1 Slabs

The slabs have been designed and detailed for amaximum Exposure Classification of B1 (nearcoastal) in accordance with AS 3600-2001. Lesssevere classifications may be appropriate for fullyenclosed carparks or for carparks in cities awayfrom the coast.

For durability and aesthetic reasons, the slabs havebeen designed in accordance with AS 3600-2001to achieve a strong degree of crack control. Specialattention should also be given to the need foradditional reinforcement in the vicinity of restraints,openings and discontinuities particularly on the toplevel, which is subjected to a great deal moremoisture in the form of rainfall.

The regions of the slabs in negative bending havebeen designed for crack control in accordance withProe, Patrick & Goh (1997). The regions at the endsof the primary and secondary beams have alsobeen checked for crack control in accordance withAdams & Patrick (1998). This has resulted inadditional reinforcement being provided aroundsome columns and over some primary beams.Propping of the slabs or beams, where the systemhas been designed as unpropped, may result inexcessive crack widths. Hence, propping should beavoided in all schemes except Scheme S3A.

Movement joints traditionally require highmaintenance and should be avoided if possible.When required, they should be detailed so that inthe event of leakage through the joint, there will notbe any adverse effect on the durability of thestructure or damage to the paint on the cars below.Consequently, the joints must not be placed over

the flange of a steel beam. A suitable detail is givenin Figure B1.

The concrete should be screeded or boxed locallyaround the steel column so that water will not pondat the column. In addition a sealant with a highmodulus of elasticity (e.g. ROADseal) should beprovided at the interface of the concrete and thesteel column so that water can not penetrate whenthe concrete shrinks away from the column.

B.2 Profiled Steel Sheeting

It is recommended that the galvanized coating onthe profiled steel sheeting complies with Table B1.(BlueScope Steel, 2004) The atmosphericclassifications in AS/NZS 2312:2002 areappropriate for steel sheeting and have beenadopted herein (refer to Table B3). For exposededge forms, a drip arrester should be incorporatedalong the edge (see drawing No S1, Section 2.3,page 25 for a suitable detail), and should be madefrom Z450 galvanized steel. For edges not exposedto the weather, a standard edge form of Z450galvanized steel is recommended.

Figure B1 - Expansion Joint Detail

Appendix BSupercast Rearguard S


B.3 Structural Steelwork

Considerable care has been taken to avoid detailsthat will lead to premature deterioration of the paintsystem. The selection of the steelwork finish willoften be governed by aesthetics as well as durability.

The top flange of the composite steel beams should

not be coated with materials that would prevent thesatisfactory welding of shear studs through theprofiled steel sheeting. Shear studs can be weldedthrough the profiled steel decking and a 25-50mcoating of a zinc phosphate primer onto the steelbeam. For atmospheric corrosivity category A it isrecommended that this sort of weld through primerbe used.

For higher atmospheric corrosivity categories it isrecommended that the steelwork be protected asindicated in Table B2. However, a strip wide enoughto accommodate the shear studs is to be to beinitially left untreated by masking the appropriatearea on the top flange. A special tape is availableto accommodate a hot-dip galvanized treatment.This area is latter treated with a 25-50m coatingof a zinc phosphate primer.

Exposed perimeter steelwork is in a more severeenvironment than the internal steelwork andtherefore should have a higher level of protection.Therefore, for perimeter beams with a slab edge

exposed to the weather, it is recommended that atthe very least, the top flange should be given acomplete coat of the protection indicated in TableB2, while the beam should be galvanized in marineand tropical environments. This means thatperimeter beams in these cases would need to benon-composite as the whole top flange of the beamwould be treated making the welding of shear studsto this surface difficult.

Table B2 gives the minimum recommended surfacetreatment based on AS/NZS 2312:2002. In somesituations, it may be better to adopt a more durablesurface coating with a higher initial cost and reducedmaintenance. Different systems can be comparedby determining the life cycle cost, using the NetPresent Value method (AS/NZS 2312:2002) of eachalternative including allowances for taxationbenefits. Systems alternative to those given in TableB2 that can be considered include:

Class 2.5 blast clean (AS 1627.0-1997) followedby one coat of inorganic zinc silicate (75m), a

Atmospheric Zinc Class

Corrosivity Category

A Z350B Z350C Z350D Z450*E Z450*F Z450*

Table B1 - Minimum Recommendations for

Profiled Steel Sheeting Coatings

Table B2 - Minimum Recommended Surface Treatment options for Various Atmospheric Classifications in Accordance with AS/NZS 2312:2002

A Blast Clean to Class 2 75m Alkyd Primer (Zinc Phosphate1) Alkyd Gloss

B Blast Clean to Class 2 75m Epoxy Zinc Phosphate Primer 50-75 m Polyurethane or Catalised Acrylic

C Blast Clean to Class 2 75m Epoxy Zinc + 125m High Build Epoxy 50-75 m Polyurethane or Catalysed Acrylic

D Blast Clean to Class 2 75m Epoxy Zinc + 150m High Build Epoxy 50-75 m Polyurethane or Catalysed Acrylicor Hot-dip Galvanized

E Blast Clean to Class 2 75m Epoxy Zinc + 200m High Build Epoxy 50-75 m Polyurethane or Catalysed Acrylicor Hot-dip Galvanized

F Blast Clean to Class 2 75m Epoxy Zinc + 125m High Build Epoxy 50-75 m Polyurathane or Catalysed Acrylic

Atmospheric Steelwork TreatmentCorrosivityCategory2 Preparation Protection Top Coats for Aesthetics

NOTE: 1. Masking of top flange is not required. Shear studs to be installed through Zinc Phosphate coating2. Refer to Table B3 for descriptions of Atmospheric Corrosivity Categories

NOTE: * Supply of Z450 may have a longer lead time and referto manufacturers recommendations.


functional system where aesthetics are lessimportant;

Class 2.5 blast clean followed by 50m epoxy

zinc and 50m 2 pack acrylic (epoxy cross linkedcatalysed acrylic) to provide an architectural finishin a range of colours

Szokolik & Rapattoni (1997) has shown that a singlecoat of water borne inorganic zinc silicate will outperform multi-coat systems. However the multi-coatsystem is given for situations where a differentcolour top coat is desired.

Table B2 is a guide only. The corrosion protectionsystem should be designed in accordance with AS/NZS 2312:2002. Labour rather than material costdrives the applied cost of coating systems. Oftensimilar corrosion resistance can be achievedindependent of aesthetics.

Reference should be made to Appendix D for costsof alternate coating systems

B.4 Monitoring

In accordance with normal practice, an inspectionwould be undertaken towards the end of thecontract defects-liability period. This should identifyitems which require ongoing monitoring such asexpansion joints.

References

Adam, J. C. & Patrick, M. 1998, Crack-controlInvestigation for Steel-framed Carparks, BHPR/N/1998/098, BHP Research - MelbourneLaboratories, Melbourne

BlueScope Steel 2004, Technical Bulletin TB-29,

BlueScope Steel Limited, Melbourne

Proe, D. J., Patrick, M. & Goh, C. C. 1997,Simplified Design of Continuous Composite Slabsincluding Moment Redistribution and CrackControl, Fifteenth Australasian Conference on theMechanics of Structures and Materials, Melbourne,pp. 147-152

Standards Australia 1997, AS 1627.0-1997 Metalfinishing - Preparation and pretreatment of surfaces- Method selection guide, SAI, Sydney

Standards Australia/Standards New Zealand 2002,AS/NZS 2312:2002 Guide to the protection ofstructural steel against atmospheric corrosion bythe use of protective coatings, SAI, Sydney

Szokolik, A. & Rapattoni, F. 1997, Single-coatInorganic Zic Silicate. Is this the Definitive Answerfor Surface Protection of Steel Bridges?,Preceedings of the 1997 Bridge Conference,Sydney


Atmospheric Description

Corrosivity

Category

Table B3 - Atmospheric Classification in Accordance with AS/NZS 2312:2002

Category A: Very low Environments in this category are most commonly found inside heated or air conditioned buildings with clean atmospheres, such as most commercial buildings. They may alsobe found in semi-sheltered locations remote from marine or industrial influence and in unheated or non-air conditioned buildings. The only external environments in Australia orNew Zealand are some alpine regions although, generally these environments will extend into Category B.

This category mainly covers coastal areas with low salinity. The extent of the affected area varies significantly with factors such as winds, topography and vegetation. Aroundsheltered seas, such as Port Philip Bay, Category C extends beyond about 50 metres from the shoreline to a distance of about one kilometre inland. For a sheltered bay orgulf, such as near Adelaide, this category extends from the shoreline to about 3 to 6 kilometres inland. Along ocean front areas with breaking surf and significant salt spray, itextends from about 1 kilometre inland to between 10 to 50 kilometres inland, depending on the strength of prevailing winds and topography. Much of the metropolitan areas ofWollongong, Sydney, Newcastle, the Gold Coast, Auckland and Wellington are in this category. In South Australia, the whole of the Yorke peninsula falls within this or a moresevere category, and in the south-east of the state, from Victor Harbour to the Victorian border, this category extends between 30 and 70 kilometres inland. Such regions arealso found in urban and industrial areas with low pollution levels and although uncommon in Australia and New Zealand, exist for several kilometres around major industries,such as smelters and steelworks, and in the geothermal areas of New Zealand. Micro-environmental effects, such as result from proximity to airports and sewage treatmentworks, may also place a site into this category. Interior environments with Category C corrosivity can occur in humid production rooms, such as food-processing plants,laundries, breweries, printing works and dairies.

Category B: Low Environments in this category include dry, rural areas as well as other regions remote from the coast or sources of pollution. Most areas of Australia and New Zealand beyondat least 50 kilometres from the sea are in this category, which can however, extend as close as 1 kilometre from seas that are relatively sheltered and quiet. Typical areasoccur in arid and rural inland regions, most inland cities and towns such as Canberra, Ballarat, Toowoomba, Alice Springs and Hamilton, NZ and suburbs of cities on shelteredbays, such as Melbourne, Hobart, Brisbane and Adelaide (except areas within 3 to 6 kilometres of the coast near Adelaide). Unheated or non-airconditioned buildings wheresome condensation may occur, such as warehouses and sports halls, can be in this category. Proximity to the coast is an important factor.

Category C: Medium

Category D: High This category occurs mainly on the coast. Around sheltered bays, Category D extends up to 50 metres inland from the shoreline. In areas with rough seas and surf, it extendsfrom about several hundred metres inland to about one kilometre inland. As with Categories B and C, the extent depends on winds, wave action and topography. Industrialregions may also be in this category, but in Australia and New Zealand these are only likely to be found within 1.5 kilometres of the plant. This category extends inside the plantwhere it is best considered as a micro-environment. Damp, contaminated interior environments such as occur with swimming pools, dye works, paper manufacturers,foundries, smelters and chemical processing plants may also extend into this category.

Category E: Very HighE-I: IndustrialE-M: Marine

This category is common offshore and on the beachfront in regions of rough seas and surf beaches. The region can extend inland for several hundred metres. (In some areasof Newcastle, for example, it extends more than half a kilometre from the coast.) This category may also be found in aggressive industrial areas, where the environment maybe acidic with a pH of less than 5. For this reason, Category E is divided into Marine and Industrial for purposes of coating selection. Some of the damp and/or contaminatedinterior environments in Category D may occasionally extend into this category.

Category F: InlandTropical

A tropical environment is found in coastal areas of north Queensland, Northern Territory, north-west Western Australia, Papua New Guinea and the Pacific Islands, exceptwhere affected by salinity. Corrosivity in inland regions is generally low (similar to that of Category B), but the aggressiveness of the environment to organic coatings meansspecial protection is required.

Note:If a site is considered to be in more than one category, for example an industry on the coast in a tropical region, then a selected coating should be capable of resisting the most severe of theenvironments involved.


C. FIRE-RESISTANCE

REQUIREMENTS

C.1 Open-deck or Sprinklered

Carparks

According to the Building Code of Australia (2004),open-deck and sprinklered carparks can beconstructed from bare steel construction providedthat the columns and beams achieve certainrequirements with respect to their surface-area-to-mass ratio.

The BCA defines an open-deck carpark as a carparkwhich is cross ventilated using two approximatelyopposite sides. The sides that provide ventilationmust be at least 1/6 of the area of any other sideand the opening must be at least 1/2 of the wallarea (see Figure C1).

C2 Not Open-deck and Not

Sprinklered Carparks

The designs in this publication are also applicableto carparks that are not open-deck or are notsprinklered, however some fire protection ofstructural elements may be required. The BCAcarparks provisions including those for non-sprinklered, non-open deck carparks are describedin detail in the OneSteel publication EconomicalCarparks A Guide to Fire Safety (Bennetts, Poh& Thomas, 2001). This document should beconsulted to determine the extent of protectionrequired.

References

Australian Building Code Board 2004, BuildingCode of Australia, Volume 1: Class 2 to Class 9Buildings, ABSB, Canberra

Bennetts, I. D., Poh, K. W. & Thomas, I. R. 2001,Economical Carparks - A Guide to Fire Safety,OneSteel Market Mills, Newcastle, Available: http://www.onesteel.com/productspecs.asp?specID=54

Figure C1 - Open-Deck Carpark (Source: Bennetts, Poh & Thomas, 2001)

Appendix C


D. COSTING

D.1 Methodology

The costing of the different carpark schemes isbased on a rational costing method, proposed byWatson et al. (1996), which divides the costs upinto the following components.

Steel Supply

Steel sections are costed in dollars per lineal metre,whereas plate and profiled sheeting are costed indollars per square metre.

Fabrication

This item covers shop drawings and transport, aswell as the fabrication activity. It is an activity-basedcosting system. The time to undertake each activityhas been derived from a detailed survey of practiceswithin the Australian fabrication industry.

Surface Treatment

Rates per square metre of treated area are used todetermine the cost of these activities.

Erection

This item covers all activities carried-out on site suchas steel erection, laying and fixing of profiled steelsheeting and welding of shear studs.

The advantages of the above methodology incosting are that it :

provides more reliable and accurate costs;

provides continuity of approach from initial project

costing through to fabricators detailed costing;

provides a clearer focus on the elements that will

have a significant effect on the final cost; and

allows reliable determination of contract variation

costs.

A Microsoft Excel 7.0 spreadsheet program wasused to determine the costs of each of the carparkschemes using the above methodology. Eachscheme is costed on a separate sheet and thisinformation is brought together on a summary sheet.The costs are based on data given by Watson et al.(1996) with an updated fabrication hourly rate of$60 and 2004 supply costs.

The accuracy of these costs has also been verifiedindependently by a number of fabricators. Assignificant attention has been given to minimise thecost of the details recommended for use, the costof the fabrication is sometimes less than thefabricators initial approximation. However, a moredetailed examination reveals that the costs arerealistic.

D.2 Costs

A summary of the base costs is given in Table D1.The base costs are derived for schemes with aCategory C exposure classification and no webpenetrations. This information has been taken fromthe summary sheet of the spreadsheet program.

D.2.1 Schemes with Edge Columns

(Schemes S1 & S4)

From the base costs in Table D1, it can be seenthat, the 4 car space schemes (S1B & S4B) withedge columns are the most economical. The 3 carspace schemes (S1A & S4A) are only slightly moreexpensive. This goes against conventional wisdomsince one would expect the 3 car space schemesto be cheaper as there is less steel. The beam

Appendix D


supply cost for Schemes S1A & S4A is $35 persquare metre whereas for schemes S1B & S4B itis $40 per square metre. However, with theseschemes there is the same amount of fabricationand erection per module. Yet the module area forthe 4 car space module is one third larger than the3 car space module. Therefore, the additionalsupply cost for the beams in the 4 car space schemeis offset by the reduced fabrication costs and thetotal cost for the beams is the same. In addition,with the 4 car space schemes there are fewermembers to erect for a given carpark and henceconstruction speed is increased.

The cost for the beams includes allowance for thecost of the connections to the columns. Thereforethe column costs include only the supply cost ofthe column, the fabrication costs associated with

the end splice, erection costs and surface treatmentcosts. It can be seen from Table D1, that the columncost per square metre for the 4 car space schemesis less than that for their respective 3 car spacescheme.

The 5 car space schemes suffer a significant costpenalty of up to $20 per square metre over the 4car space schemes. This is largely due to theincrease in steel supply cost of $10 per squaremetre. The remainder is made up of increasedfabrication and surface treatment costs due to thelarger members and connections.

Schemes S1B, S1C, S4B and S4C offer a smallimprovement in utilisation of the floor area (seeTable 3) which should be taken into account whencomparing the different schemes.

D.2.2 Schemes with a Cantilever Edge

(Schemes S2 & S5)

This layout is only given for a 3 car space schemeas the cantilever size proved uneconomical forlarger module widths. The steel supply cost wasonly slightly more than for the edge column solution.However, the fabrication costs increasedconsiderably with the moment connections. For themultiple module Scheme S5, this additional cost isspread over a greater floor area and hence is notas obvious as the single module Scheme S2 whichhas two cantilevers in a single module.

D.2.3 Scheme with a Clear Span

(Scheme S3A, S3B & S3C)

Clear span solutions offer a very efficient layout withmore car spaces in a given footprint. Theseschemes are also very appealing to the user asthere are no internal columns that are a potentialsource of damage to cars. For this reason they arepopular in carparks with high turnover, particularlyin shopping centres.

The total cost of Scheme 3A is very sensitive to thecomponent cost of propping the slab duringconstruction, however if this is well managed themore efficient usage of space almost pays for theadditional cost over the schemes that are not clearspan.

The additional cost of schemes 3B and 3C aregenerally accepted by owners on the basis of theadditional appeal it offers the users of the carpark.

Scheme Floor Costs Column Costs TOTAL COSTS$/m2 $/m2 for (Floor and Columns) $/m2 for

No. of storeys No. of storeys

Beams Decking Slab TOTAL 2 4 6 8 2 4 6 8

1A 83 40 55 178 12 15 17 19 190 193 195 1971B 81 40 55 176 9 12 15 17 185 188 191 1931C 101 40 55 195 9 12 14 17 204 207 209 2122 94 40 55 189 10 11 12 15 199 200 201 204

3A 73 49 58 180 22 19 24 25 202 199 204 2053B 132 40 55 226 8 10 12 14 234 237 239 2403C 135 40 55 230 7 9 10 13 237 239 240 2434A 84 39 55 177 9 12 15 19 187 190 192 1964B 80 39 55 174 8 11 15 18 182 185 189 1924C 97 39 55 191 8 10 14 16 199 201 205 2075 87 39 55 181 9 10 12 15 190 191 193 195

Table D1 - Summary of Indicative Costs (Surface treatment: Refer to Table B2 Category C)

NOTE: To obtain the total cost of the carpark floor and columns, multiply the cost for the relevant number of storeys by the total area.


D.3 Different Surface Treatment

Systems

The cost of surface treating or painting the steelworkhas a major influence on the initial cost of a carpark.The cost of different paint systems for each of theseschemes is given in Table D2. It should be notedthat an additional $5/m2 allowance to mask the topflange and to later treat with a weld through primerhas been included in the costs for all paint systemsexcept for category A. Scheme 3A is significantlyless than the other schemes as there are fewermembers involved. This makes this scheme moreattractive if the more expensive protective systemsneed to be used.

D4 Penetrations

The cost of large reinforced penetrations in the websof steel beams can have a significant influence onthe cost of a floor. However, in a carpark, suchpenetrations are usually not required. Circular andrectangular unreinforced penetrations that willgenerally cater for the necessary hydraulic servicesin a carpark can be economically provided in theprimary beams. For example 200 diameterpenetrations in each of the primary beams will costin the order of 25 cents per square metre over theentire carpark. The indicative costs of different typesof penetrations that are commonly used are givenin Table D3.

D.5 Column Splices

The cost of column splices is quite substantial. Thefabrication cost is generally between $240 and $320per splice. To this the additional cost of shopdrawings, transport and erection has to be added.This brings the total cost of a splice to between $520

Table D2 - Surface Treatment Costs

Scheme Protection System Costs $/m2

Atmospheric Corrosivity Category Add. Top Add. Top Hot-dip

A B C D/F E Coat A1 Coat Oth2 Galvanized

S1A 9 14 15 20 21 8 11 14S1B 10 15 16 21 23 9 12 14S1C 12 18 20 25 27 12 16 25S2 10 15 16 21 22 9 12 16

S3A 6 9 10 13 14 6 8 12S3B 14 22 24 32 34 14 19 31S3C 14 21 23 31 33 14 19 30S4A 10 15 16 21 22 9 12 15S4B 10 15 17 21 23 9 12 15S4C 11 17 18 24 25 11 15 23S5 9 14 15 20 21 9 12 15

Penetrations Unreinforced Reinforced

Section mass Circular Rectangular Rectangular Rectangular Rectangular

(kg/m) Hours $ Hours $ Hours $ Hours $ Hours $

< 60.5 0.4 24 0.7 42 2.0 120 3.4 204 4.2 25260.6 to 160 0.5 30 0.8 48 2.4 144 4.1 246 5.7 342160.1 to 455 0.7 42 1.2 72 3.7 222 6.1 366 8.5 510

Diagram

Note: Based on an hourly rate of $60

Table D3 - Cost of Penetrations

Notes:1. Cost of additional top coat applied over Category A finish2. Cost of additional top coat applied over all other surface finishes except Hot-dip Galvanized


and $800. Therefore, in general it is better tominimise the number of splices rather than the massof the column.

The maximum length of column section that isreadily available and still easy to handle is 18metres. Therefore, it is recommended that forcarparks less than four levels high, the columnsare made from one length (without splices). With asix level carpark, the cost of a non-prismatic columnwith splices is similar to that of a prismaticcontinuous column. The choice will depend on thescheme being adopted and the time allowed forfabrication and erection. For an eight level carpark,it is suggested that a splice be provided at mid-length for maximum economy.

References

Watson, K. B., Dallas, S., van der Kreek, N. & Main,T. 1996, Costing of Steelwork from Feasibilitythrough to Completion, Journal of AustralianInstitute of Steel Construction, vol. 30, no. 2


E. SURVEY OF EXISTING

CARPARKS

There have been a significant number of steelcarparks constructed in Australia and New Zealandof various configurations in plan and elevation. Thisappendix lists many of these carparks.

Information on these are presented in tables, foreach state of Australia, and one for New Zealand.These tables provide available information on eachof the carparks.

Appendix E


ACTDickson Shopping Centre, Dickson, Canberra 4 326 1996 Precast 3 Scheme S1AWoden Valley Hospital, Woden Valley 2 350 1994 Tensioned slab 3

on steel columnsManuka Carpark, Corner Furneau & Bouganville Road, Manuka 1 170 1993 Composite 3 Scheme S1AANU Carpark, ANU, Canberra 3 330 1985 Precast 3 Scheme S1ANational Gallery of Australia, Parkes Place, Canberra 1 1974 Cast in-situ rc slabCity West Carpark, Civic, Canberra 5 1100 CompositeNorthern TerritoryK- Mart, Palmerston, Darwin 1 400 1998 CompositeQueenslandGary Crick Auto 1 150 2003 Composite Continuous

composite beamsCapalaba Shopping Centre, Capalaba, Brisbane 1 200 1995 Composite 3Petrie Rail Interchange, Petrie 1 270 1993 Precast 3 Scheme S2St Andrews Hospital, North St, Spring Hill 1 42 1993 Precast 3 Scheme S1ACity Centre Plaza, Rockhampton 2 330 1990 CompositeMal Burke, Southport 1 90 1988 Precast 2Rockhampton Shopping Centre 1 300 1987 Composite 3Sunnybank Hills Shoppingtown, Sunnybank Hills 3 1600 1987 Composite 3Valley Centre, Fortitude Valley 2 130 1978 Cast in-situ rc slab 2

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Table E1 Survey of Existing Carparks ACT, Northern Territory and Queensland

Carpark Type


New South WalesNowra Fair Shopping Centre, Haigh St, Nowra 1 80 2000 Composite 3Cowra Carpark, Busby Place, Cowra 1 70 Composite 3Westfields Hornsby Carpark Extension 1 150 2001 Composite infAlbury Commercial Club Carpark, Albury 2 160 2001 Composite 3TNT Office Carpark, Mascot 3 200 2000 Composite 4 Scheme S1B.Parramatta RSL Carpark, Parramatta 3 190 2000 Composite 4 Scheme S1B.Prince of Wales Carpark, Prince of Wales Hospital, Randwick 2 270 1998 Composite 3Big W Retail Carpark, Griffith 1 360 1997 Composite 3King Street Carpark, King Street, Newcastle 3.5 160 1997 Composite 3 Scheme S4AMascot Airport Carpark -Stage 4, Keith Smith Avenue, Domestic Terminal, Mascot 4 1997 Stressed concrete slab 2HIA Building & Renovata Supa Centre, Homebush Bay 2 190 1996 Composite 3Liverpool Hospital Carpark, Liverpool 3 456 1995 Precast 3Thornleigh Railway Station, Yarrara Street, Thornleigh 2 1994 Precast - untopped 3Murwillumbah Hospital Carpark, Murwillumbah 2 80 1991 Precast 3 Scheme S1ABankstown City Council Carpark, Brandon Avenue, Bankstown 3 240 1988 Composite 2 Scheme S3Blacktown City Council Carpark, Nelson Lane, Blacktown 4 500 1987 Cast in situ rc slab 2IBM Carpark, Coonara Avenue, West Pennant Hills 8 630 1987 Cast in situ rc slab 2Novotel Hotel Carpark, Darling Harbour 4 1800 1987 Composite 2 Scheme S3Forest Centre Carpark - Stage 3, Forest Way Shopping Centre, Frenchs Forest 1 80 1986 Composite 2 Scheme S3Pender Place Shopping Centre Carpark, Maitland 2 113 1985 CompositeWest Terrace Carpark, West Terrace, Bankstown 2 200 Stage 1-1978 Cast in situ rc slab 5 Scheme S4A

Stage 2-1984Mascot Airport Carpark, Keith Smith Avenue, Domestic Terminal, Mascot 3 3000 Stage 1-1970 Cast in-situ rc slab. 2

Stage 2-1976Forest Centre Carpark - Stage 2, Forest Way Shopping Centre, Frenchs Forest 1 100 1972 Composite 2 Scheme S3Ward Street Carpark, Ward Street, North Sydney 3 1970 Composite 3

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Table E2 Survey of Existing Carparks New South Wales

Carpark Type


South AustraliaMt Barker Carpark, Cnr. Druids Ave & Adelaide Rd 1 286 2003 Composite 3 W-deckThe Royal Adelaide Hospital Carpark 9 1440 2002 Composite 3 W-deckMill Street Auto Park 8 519 2001 Composite & non-composite 2Christian Brothers Sport Centre, Flinders St 1 120 1998 Composite/precastEDS, North Terrace, Adelaide 4 245 1998 Composite 4Mt Gambier 1 302 1998 Composite 3Salvation Army, Pirie St 1998 CompositeAdelaide University, Frome St, Adelaide 6 500 1997 Composite 3Childrens Hospital, Kermode St, Nth Adelaide 5 125 1995 Composite 3Hindley Plaza, Clubhouse Lane 6 294 1995 Composite 32 Floor Extension, Grenfell St 2 120 1992 Composite 3Flinders Medical Centre, Bedford Park 4 420 1991 Composite 2Blyght St 5 1990 CompositeChildrens Hospital, Kermode St, Nth Adelaide 5 400 1989 Composite 3Playhouse Lane, Light Sq. 7 375 1989 Composite 2Wyatt St 4 760 1989 Precast 2Roper St 7 644 1988 Precast 2 RampedSouthgate, South Terrace, Adelaide 4 320 1987 Composite 2Miller Anderson, Hindley St 3 1986 Composite 3Pirie St 4 590 1986 Precast 2 & 3 RampedCentral Market, Grote St 2 1090 1982 Precast 3 & 4Cnr Rundle St & Poulterny St 7 850 1974 Composite 4 Castellated Beams

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Table E3 Survey of Existing Carparks South Australia

Carpark Type


VictoriaDeakin University, Melbourne Campus, Burwood 3 2003 Composite str. steel 3 Add-a-top WestFederation Square Russell St Extn, Melbourne 3 2003 Composite str. steelLittle Lonsdale St, Melbourne AddaTop 6 2003 Composite str. steelMonash University, Clayton Campus North West Section 1 2 2003 Composite str. steel 3 Add-a-TopDeakin University, Melbourne Campus, Burwood 3 2002 Composite str. steel 3 Add-a-top EastGrocon QV Tentants BHP Billiton, Melbourne 5 2002 Composite str. steel 3Klopfer & Dobos Waverley Rd, Glen Waverley 1 15 2002 Composite str. steelMonash University, Clayton Campus North West Section 1 2 2001 Composite str. steel 3Pran Central Wattle St, Prahran 2 2001 Composite str. steelHickory Developments Cnr Smithfield & Epsom Rds, Kensington 1 36 2001 Non compositeSalta Properties Cook St, Port Melbourne 2 2001 Composite str. steel209 Kings Way South, Melbourne 6 2001 Composite str. steelBlakford 370 Queen St, Melbourne 2 2001 Composite str. steelDeakin University, Burwood Hwy, Burwood 2 587 1998 CompositeBlessed Sacrament Fathers - St Francis 312, Lonsdale St, Melbourne 6 530 1992 Non composite SprinkleredMaroondah Hospital, Mt Dandenong Rd, Ringwood 1 1992 Non compositeHeidelberg City Council, 21 Yarra Bvd, Heidelberg 1 1991 CompositeWatt Street Carpark, Watt St, Box Hill 4 1991 Composite624 Bourke Street, Melbourne 4 1990 Composite SprinkleredAustrailian Customs Service, 414 Latrobe St, Melbourne 3 81 1990 Composite SprinkleredChandler Hwy, Northcote 1 200 1990 Non composite SprinkleredEndeavour Hills Shopping Centre, Mathew Flinders Ave, Endeavour Hills 1 1990 Non composite SprinkleredFlinders Gate, 172 Flinders St, Melbourne 12 1100 1990 Non composite SprinkleredFrankston City Council, Ross Smith Ave, Frankston 3 1990 Composite SprinkleredGlenferrie Road, Malvern 2 50 1990 Composite

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Table E4 Survey of Existing Carparks Victoria

Carpark Type


Victoria (Contd.)Grand Mercure Hotel, 333 Collins St, Melbourne 5 364 1990 Composite SprinkleredMacedon Square Shopping Centre, Manningham Rd, Templestowe Lower 1 1990 Composite Sprinklered17 Burgundy St, Heidelburg 1 1989 Composite Sprinklered9 Porter St, Dandenong 2 1989 Composite SprinkleredBurwood Highway, Knoxfield 1 1989 Composite SprinkleredCommercial Union Assurance Co of Australia, Lonsdale St, Melbourne 3 1989 Composite SprinkleredJolimont St, East Melbourne 1 1989 Composite SprinkleredMt Eliza Way & Canadian, Mt Eliza 1 1989 Composite SprinkleredCarlton & United Breweries, Flockhart St, Abbotsford 4 450 1988 CompositeCnr Kooyong & High Sts, Armadale 1 1987 CompositeVictorian Operative Bricklayers Society, Bary St, Carlton 6 1987 CompositeChambers St, South Yarra 2 20TasmaniaHobart City Council, Argyle St Carpark Extension, Hobart 2 1994 CompositeLaunceston City Council, Paterson St West Carpark, Launceston 6Western AustraliaCollie Street, Fremantle 9 split level 448 2003 Composite 2 Clear span, Scheme S3Call Centre, Bunbury 1 2003 Composite 3 Scheme S4AMelville Plaza Carpark 1 231 2002 Precast 3 Structure erected in 9-daysColes Myer, Kalgoorlie 1 142 1997 Ultrafloor 3Karrinyup Shopping Centre, Francis St, Karrinyup 1 218 1997 Precast 3Curtin University - Carpark 2, Dumas St, Bentley 1 290 1996 Precast 348 Mount Street, Perth 1 24 1993 Precast 3St Quentins, 337-339 Stirling Hwy, Claremont 2 175 1991 Composite 2 Scheme S3

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Table E5 Survey of Existing Carparks Victoria (Contd.), Tasmania and Western Australia

Carpark Type


New ZealandSt Mathews Carpark, Hobson St, Auckland 4 131 1996 Speedfloor trusses with 90 mm conc 3Teachers College Carpark, Union St East, Dunedin 2 3000 1996 130mm slab on HiBond 0.75 bmt Decking 2Newmarket Carpark, Broadway, Auckland 6 507 1996 130mm slab on HiBond 0.75 bmt Decking 4Arthur Barnetts, George St, Dunedin 4 456 1996 130 mm topping on 0.95mm HiBond 3Watt St Carpark, Watts St, Auckland 3 99 1995 Speedfloor trusses with 90 mm conc 3Great King St Carpark, Great King St, Dunedin 4 360 1994 130 topping on HiBond 4Skycity Carpark, Hob St, Auckland 5 1998 1994 130 -200 mm topping on 0.75mm HiBond 3Wakefield Street, Wakefield St, Auckland 6 350 1986 HiBond 3

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Table E6 Survey of Existing Carparks New Zealand

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Appendix F F. EXAMPLES OF RAMPCONFIGURATIONS

Common ramp configurations for both one-way andtwo-way traffic flow are presented in this appendix

Figure F1 - Examples of Ramp Configurations

for Combined Single Module Split level

carparks (refer to Figure 4a)

Figure F2 - Example of Ramp Configurations

for Multiple Module Schemes

(refer to Figure 5)

(a) One way traffic flow - Fast exit (b) One way traffic flow - Scissor ramp

(c) Two way traffic flow - Two way ramps

carpark design guide

Documents