method stat ijm launch

DELHI METRO RAIL CORPORATION

ELEVATED VIADUCT FROM KM 0.62 TO KM 8.00 ON BARAKHAMBA ROAD – CONNAUGHT PLACE – DWARKA

SECTION (LINE NO.3) 3C21R

METHOD STATEMENT FOR LAUNCHING OF SEGMENTS

Document No : 215/DMRC/3C21R/MS-13/R-1Pages : 1 TO 141Date : 09.04.2004

CONTRACTORS:IJM-NBCC-VRM JV

CONSULTANTS:

ARCH CONSULTANCY SERVICES (P) LTD.IN ASSOCIATION WITH

BRIDGECON INDIA

CONTENTS

1.0 INTRODUCTION

1.1 Configuration requirement for Delhi metro project

1.1 Drawings

1.2 Steel Fabrication

1.3 Safety

2.0 MAIN COMPONENTS OF LAUNCHING GIRDER

2.1 General

2.2 Main Box Girder

2.3 Front Support

2.4 Middle Support

2.5 Rear Support

2.6 Rear Trolley

2.7 Slider Beam

2.8 Moving Trolley

2.9 Counter Weight

2.10 Fixed Mounted Hoist

2.11 Platform / Walk way

3.0 SCHEME FOR AUTOLAUNCHING

3.1 General

3.2 List of Drawings for ready reference

3.3 Steps for Auto Launching

4.0 STAGES OF ERECTION OF SPAN

4.1 General

4.2 List of Drawing

4.3.1 Erection Procedure for 31.0m Span

4.3.2 Erection Sequence of Precast Segments in Different Span

1

5.0 MANUAL FOR ERECTION OF FIRST SPAN

5.1 General

5.2 List of Drawings

5.3 Erection of Launching Girder in First Span.

6.0 REFERENCES

ANNEXURE A

PROCEDURE FOR VERTICAL ROTATION

A.1 General

A.2 Detailed Description of Various Conditions of Launching Girder in Vertical

Grade & Corresponding Height Adjustment of its Supports.

A.2.1 Down Grade

A.2.2 Up Grade

A.3 Permissible Range of Height to be Ensured at Front Support

A.4 Calculation of Height at Front Support For a Known Height at Rear Trolley

and Middle Support

A.4.1 Down Grade

A.4.2 Up Grade

ANNEXURE B

PROCEDURE FOR MOVEMENT OF MIDDLE SUPPORT / REAR

SUPPORT USING MOVING TROLLEY

ANNEXURE C

PROCEDURE FOR RAISING / LOWERING OF TELESCOPIC LEG /

BOTTOM BEAM OF FRONT SUPPORT

2

1.0 INTRODUCTION

This document has been specifically written for the Launching Girder to be used in

DMRC Project: BARAKHAMBA ROAD – CONNAUGHT PLACE – DWARKA

SECTION (LINE NO.3)

This document covers following sections:-

(a) Description of Launching Girder

(b) Scheme for Auto Launching & Erection

(c) Description of Operations performed by various parts of Launching Girder.

(d) Safety

1.1 CONFIGURATION REQUIREMENT FOR DELHI METRO PROJECT

This section includes requirements and information regarding the configuration of the

bridge and Launching Girder

S.No. Item Criteria

1. Maximum span length 31.0m

2. Minimum span length 16.0m

3. Maximum longitudinal slope 2.74%

4. Maximum weight of segment 80.0 t

5. Maximum length of segment 3.0m

6. Minimum Horizontal radius 302.05m

7. Total height of intermediate segment 2.0m

8. Total height of end segment 3.0m

9. Segments gluded or dry jointed Epoxy Glue

10. Loading of segments from ground / rear From ground only

3

1.2 DRAWINGS:

The following drawings apply to DMRC project:

S. No. Title Drawing No.

1. General Arrangement of Launching Girder 215/LG/01

2. Details of Launching Girder (Sh.1 of 3) 215/LG/02



5. Details of Monorail 215/LG/03

6. General Arrangement Erection stage lifting 215/LG/04

7. Details of wire rope assembly for intermediate segment 215/LG/05

8. Scheme for auto launching (Sh.1 of 3) 215/LG/06



11. Details of Middle Support (Sh.1 of 7) 215/LG/07







18. Details of Front Support (Sh.1 of 6) 215/LG/08






24. Details of Rear Support (Sh.1 of 3) 215/LG/09



27. Details of Rear Trolley (Sh.1 of 5) 215/LG/10



4



32. Details of Sliding Beam (Sh.1 of 2) 215/LG/11

33. Details of Sliding Beam (Sh.2 of 2) 215/LG/11

34. General Arrangement for Temporary Prestressing (25.0m) 215/LG/12

35. Details of Lifting & Temporary Prestressing for End

Segments Erection Stage (Sh.1 of 4)

215/LG/13



215/LG/13



215/LG/13



215/LG/13

39. Details of Lifting & Temporary Prestressing for Intermediate


215/LG/14



215/LG/14



215/LG/14



215/LG/14



215/LG/14



215/LG/14

45. Scheme for Erection of precast segments (Sh.1 of 2) 215/LG/15

46. Scheme for Erection of precast segments (Sh.2 of 2) 215/LG/15

47. Details of Bracket for fixed-mounting-hoist 215/LG/16

48. Details of counter weight 215/LG/17

49. Erection sequence of launching girder in first Span (Sh.1 of 3) 215/LG/18



Note: A complete set of above drawings should be available at site for ready reference.

5

1.3 STEEL FABRICATION

The Launching Girder including all its accessories will be fabricated with the

drawings supplied by Arch Consultancy Pvt. Ltd. unless otherwise communicated

through a written document.

Items modified or rectified during assembly shall be reported for discussion & final

details must be supplied to Arch Consultancy Services Pvt. Ltd.

1.4 SAFETY

Safety shall be ensured as per safety manual.

This manual should include the following information:

- Safety Personnel

- Site Training

- Personal Protection Equipments i.e. safety boots, safety nets.

- Lifting of parts and equipments

- Use of flame cutter and welding sets

- Storm wind / Emergency conditions

- High power cable

6

2.0 MAIN COMPONENTS OF LAUNCHING GIRDER

2.1 General

This sections gives a brief description of main parts of Launching Girder. Reference

shall be made to the detailed drawings.

This section is built up as follows:

Main Box Girder……………..(Refer Drg .No. LG /02 sheet 1 of 3 to 3 of 3)

Front Support………….……..(Refer Drg .No. LG /08 sheet 1 of 6 to 6 of 6)

Middle Support………..……..(Refer Drg .No. LG /07 sheet 1 of 7 to 7 of 7)

Rear Support……….…….…..(Refer Drg .No. LG /09 sheet 1 of 3 to 3 of 3)

Rear Trolley……….………....(Refer Drg .No. LG /10 sheet 1 of 5 to 5 of 5)

Slider Beams……….………...(Refer Drg .No. LG /11 sheet 1 of 2 to 2 of 2)

Moving Trolley……...……….(Refer Sketch No. LG/SK-02)

Counter Weight……………....(Refer Drg .No. LG /17)

Fixed Mounted Hoist…….…..(Refer Drg .No. LG /16)

Platform / Walk ways…….…..

2.2 Main Box Girder

Main Box Girder has been split in seven close plate girder (box type steel structures)

of length 9.250m each. These are spliced at their ends with the help of 24 dia. HSFG

bolts. The details of splicing & bolting arrangements have been shown in drawing no.

(LG/02 Sheet 1 of 3 to Sheet 3 of 3).

Bearing stiffeners have been provided at all support locations covering all span

ranges. In addition normal stiffeners are also provided at 975 c/c.

The Launching Girder main box structure rests on four supports viz.

Front Support

Middle Support

Rear Support

Rear Trolley

7

2.3 Front Support

Front Support consists of following parts

Top Beam

Top vertical leg

Telescopic leg

Bottom Beam

Slide bracing & Tie members

This support has in built ability for adjustment of height depending upon the situation

encountered at the site. This flexibility is provided by the telescopic leg which can

move into the top vertical leg & can be locked using 100Ø pin provided in the

support. The tie members are fixed to the top vertical leg. The side bracing connects

top vertical leg with the bottom beam. The change in length of side bracing during

adjustment in height of support can be partially done by changing its points of

connection with vertical leg for which four different connection holes have been

provided & partially by 300mm long screw jack provided at its bottom.

The entire support rest on concrete pedestals provided in the pier cap as shown in the

drawing no. LG/08, The Front Support is secured to the pier cap using 32Φ anchor

bolts.

Note: Maximum height of the front support = 5370mm

Minimum height of the front support = 3690mm

Measured from top of support to bottom of its bottom beam.

The front support is fixed at 2500 mm from the front of the launcher. Two nos.

vertical hydraulic jacks (150t capacity) are provided to carry out vertical adjustment

of the support. Side shifting of front support with respect to Launching Girder is not

possible.

10

2.4 Middle Support

The middle support is positioned on the rear pier segment and supports the launching

girder together with the front support during the span erection. The level of middle

support can be varied using 4 number single acting hydraulic jacks, (200T capacity).

Middle Support consist of following main parts

(1) Side beam B2 – 2nos.

(2) Cross beam B1

(3) Launching bearing – 2nos.

3.1 Longitudinal sliding bearing

3.2 Kunckle bearing

3.3 Cradle

(4) Longitudinal pushing assembly

(5) Braking assembly

Side beams (B2) rests over 200t capacity single acting jacks as shown in the drawing

no. LG/07 & forms the basic supporting structure of middle support. Side Beams (B2)

are connected by cross beam B1 provided at its top. Cross beam provide support and

sliding surface (Stain less Steel top) for the Launching Bearing.

Launching Bearing consists of three parts

a) Longitudinal sliding bearing which consists of a sliding surface over which the

launching girder slides during auto launching process.

b) Knuckle bearing, it consist of a 165Ø pin connecting four vertical plates. The

launching girder can be vertically rotated over this knuckle pin.

c) Cradle consists of a vertical pin embedded into steel stool over which the whole

Launching girder can rotate horizontally. It is provided with a PTFF sliding

surface at its bottom side, which assists its transverse movement over cross beam

– B1.

15

The whole assembly of launching-bearing can be pulled when required by the help of

macalloy bar connecting the cross B1 & the cradle to ensure proper position of the

launching bearing with respect to the cross beam B1.

Longitudinal pushing assembly is an independent device attached to the monorail on

front side of middle support through longitudinal movement jack connected to a

bracket provided at center of plate connecting the two cradles. This assembly is

responsible for forward movement of launching girder during auto launching

operation.

Braking assembly is another independent assembly provided at the rear side of middle

support. It is mounted on monorail & can be connected to the middle support through

40Ø pin as shown in the drawing LG/07. When this assembly is connected to the

support it restricts forward movement of launching girder with respect to the support.

16

2.5 Rear Support:-

Rear Support is a replica of middle support except that longitudinal pushing assembly

is not provided in this support. As rear support shares lesser load compared to load

shared by middle support therefore the capacity of supporting jacks have been

restricted to 100t as shown in the detail drawing LG/09.

19

2.6 Rear Trolley

The Rear trolley is positioned 4450mm from the rear end of the main box girder and

provides support during longitudinal launching.

It is A type truss supported on eight wheels which rests on 90R rails laid on the

erected superstructure at a spacing of 4.7m c/c.

The top beam of the truss is connected through four no knuckle pins so that it can

rotate vertically if required & maintain proper contact with the Launching Girder.

Launching Girder rest directly on the top beam of this support through SS verses SS

interface provided between the two.

After launching along a curved span, it is necessary for the main box to be side shifted

on the rear trolley. Macalloy bars have been provided to pull the main box over

stainless steel plates fixed on top beam of the rear trolley.

The Launching Girder can be locked with respect to this support with the help of four

set of macalloys bars passing through brackets provided in launching girder &

movable bracket consisting of two ISMC 200 & bolted at top & bottom end.

22

2.7 Slider Beams

Slider beams are independent assembly of two built up I sections connected together

with the help of stiffeners. Slider beams rests on 40 x 40 plate with 3 thick SS plate

fitted on top of launching girder main box as shown in drawing no.LG/02.

The slider beams are provided with two suspender bars at each end, which can move

500mm on either side in transverse direction while maintaining a constant distance of

5.8m among themselves.

The tension bars are connected to two beams that have been secured to the precast

segment. Vertical adjustment is carried out using the vertical tension bars while

transverse movement is done using the horizontal jacks positioned on top of the slider

beam.

The longitudinal position of segment / slider beam is adjusted through a cable running

through all the slider beams which is pulled by two monojack fitted at extreme ends

of the launching girder main box.

25

2.8 Moving Trolley

Moving trolley is an independent device consisting of two stools resting on a platform

mounted on four wheels. It is mainly used for forward movement of middle support &

rear support.

Moving trolley is also useful for temporarily supporting the rear support & middle

support for minor repair / maintenance of supporting jacks.

Note: Moving trolley is not designed for supporting middle support or rear support

during erection & the same shall be avoided.

29

2.9 Counter Weight

A counterweight is provided in the form of pre-cast concrete segments, which will

remain fixed at the rear end of Launching girder during entire launching process

unless otherwise specified in some special circumstances. This counter weight

balances the launcher during auto launching of the Launching Girder.

2.10 Fixed Mounted Hoist

It is a electrically operated device fixed over a bracket provided at 13.4m from the

front end of the Launching Girder. It has a lifting capacity of 80 t & is meant for

lifting of precast segment during erection stage.

2.11 Platform / Walk way

Working platforms have been provided at all the supports for operating mechanisms

associated with each support. Details of access plat forms have been provided in the

detailed drawings of the supports.

The main body of the Launching Girder is a close – box type structure with a width of

2.0m so that persons operating the Launching Girder can walk along its entire length

when required. However, in general practice, a separate ladder shall be used wherever

permanent access is not provided.

31

3.0 SCHEME FOR AUTOLAUNCHING OF LAUNCHING GIRDER

3.1 GENERAL

The term auto launching used here stands for forward movement of Launching

Girder from already erected span to the span to be erected.

This section gives a simplified step-by-step sequence of auto launching of

Launching girder in chronological order of auto launching process. Extracts

from various drawings have been incorporated for ready reference to site

engineers.

To simplify and to avoid mishapenings during auto launching several

checklists have been presented along with the following detail, which shall be

strictly adhered by the construction engineers.

3.2 LIST OF DRAWINGS FOR READY REFERENCE

Drawing nos. Title

LG/06

(Sh. 1 of 3 to Sh. 3 of 3)

Scheme for Auto Launching

33

3.3 STEPS FOR AUTO LAUNCHING

STAGE – 1

Step 1 The Launching Girder rests on the already erected span as shown.

Step 2 Bring the slider beams backward so that one slider beam rests at 4.45 m from

the end of Launching Girder (Near Rear Trolley) & all other slider beams rests

in succession at spacing of 0.9m.

Step 3 Affix the 90 R rails on the newly erected span for further movement of

Launching Girder.

34

STAGE – 2

Step 1 Remove the brakes provided at middle support by removing pins connecting

monorail & the braking assembly.

Step 2 Check the Jacks of Rear Support & ensure that it experiences a minimum

reaction of 10tonnes (total reaction on four jacks) on it.

Step 3 Position the moving trolley below the middle support exactly at the center of

it.

Step 4 Close the jack of middle support so that the reaction on the jack of middle

support is fully released. As a result of which, the reactions will be transferred

on the jacks of rear support & the middle support finally rests on the moving

trolley.

Note: Allowable reaction to be transferred on intermediate segment through rear

support = 120tonnes

Step 5 Open the anchors of middle support to allow its forward movement.

Step 6 Move the middle support with the help of moving trolley & position it over the

front pier segment of newly erected span so that a distance of 0.9 m is

achieved between the expansion joint of the span & centerline of the middle

support.

(Refer sketch showing position of middle support over pier segment in plan on

next page)

Note: Refer detailed procedure for movement of middle support /rear support using

moving trolley from annexure B.

Step 7 Open the jacks of middle support to transfer a minimum reaction of 10tonnes

on it ensuring that the moving trolley is released.

36

Step 8 Anchor the middle support (i.e. tie it with the pier segment). Now move the

moving trolley from the middle support position & place it below rear support.

Step 9 Apply brakes at middle support.

Step 10 Remove the brakes provided at rear support by removing pins connecting


Step 11 Close the jacks of rear support so that the reaction on jacks is fully released as

a result of which the reaction will be transferred automatically over jacks of

middle support & the rear support finally rests on the moving trolley.

Step 12 Open the anchors of rear support to allow its forward movement.

38

STAGE - 3

Step 1 Move the rear support with the help of moving trolley & position it over pier

segment as shown so that a distance of 0.9m is achieved between center line

expansion joint of the span & the center line of the rear support.

(Refer sketch showing position of rear support over pier segment in plan on

next page)

Note: Refer detailed procedure for movement of middle support /rear support using

moving trolley from annexure B.

Step 2 Anchor the rear support at this position (i.e. tie it with the pier segment).

Step 3 Open the jacks of rear support so that the jacks experiences a reaction of

10tonnes (total reaction on four jacks) on it.

Step 4 Apply brakes at rear support.

Step 5 Move the moving trolley from rear support position & place it below middle

support.

Step 6 Remove the brakes provided at middle support by removing pins connecting


Step 7 Close the jacks of middle support so that the reaction on jacks is fully released

as a result of which, the reaction will be transferred over jacks of rear support

& the middle support rests over moving trolley.

40

STAGE - 4

Step 1 Move the middle support & position it over front pier segment of the newly

erected span so that a distance of 0.9m is achieved between centerline

expansion joint of the span & the centerline of middle support as shown.

(Refer sketch showing position of middle support over pier segment in plan on

next page)

Step 2 Open the jacks of middle support to transfer a reaction of 10tonnes (total

reaction on four jacks) on it.

Step 3 Anchor the middle support (i.e. tie it with the pier segment).

Step 4 Attach longitudinal movement jack with the middle support

Step 5 Remove the 100Ø pin provided in the telescopic leg of the front support using

jacks provided over the bottom beam of front support.

Step 6 Close the jacks of the front support & remove the jacks along with stools

provided, so that the reaction is fully transferred to the middle support.

STAGE - 5

Step 1 Close the telescopic leg of front support to its minimum length as shown in the

drawing and lock it in this position so that the front support hangs over the

launching girder.

Note: Refer detailed procedure for lowering / raising of bottom beam/ telescopic leg

of front support from annexure C.

43

STAGE – 6

Step 1 Rotate the Launching Girder vertically by lowering the jacks of rear support so

that the bottom of launching girder rests over the top beam of rear trolley.

Procedure for vertical rotation

1. Lock the knuckle pins of rear trolley using 20 bars provided on its both sides.

2. Close the jacks provided in box S-7 of Launching Girder

3. Lower the jacks of rear support until the bottom of launching girder touches

the top of rear trolley.

Note: In case the minimum height of rear support is achieved before achieving

contact between launching girder & rear trolley then the same can be achieved

by raising the jacks of middle support.

4. Remove the 20 bars provided on the sides of Knuckle pins of rear trolley to

allow free rotation of Knuckle pins in vertical plane.

Step 2 Align the Girder horizontally by pulling macalloy bar at rear trolley so that

centerline of Launching Girder passes through the center of middle support

and rear trolley.

For straight span this step is not required.

PROCEDURE FOR HORIZONTAL ROTATION

1. Ensure that the Rear Trolley, Rear Support & Middle Support are properly

anchored at their respective positions.

2. Ensure that the Front Support telescopic leg is closed to its minimum so that

there is no possibility of clash between brackets / projections in bottom beam

47

of the front support & the pier segment of the already erected span & the shear

key provided at the pier cap during rotation.

3. Loosen the Macalloy bars connecting the launching girder with top beam of

the rear trolley

Note: Do not remove the channels provided below top beam for anchoring unless it

is required to cross the knuckle pins.

4. Anchor the middle support cradles using the Macalloy bars provided over the

cross beam B1 so that it doesn’t get pulled during rotation process.

Note: The cradles must be connected to each other by a suitable system so that their

c/c distance of 1.8m is maintained during rotation.

5. Clamp the anchor plates of longitudinal sliding bearing of middle support &

rear support as shown.

(Refer sketch on next page)

6. Loosen the macalloy bar anchor provided at top of cross beam B1X at rear

support so that the cradles are free to move in the required direction along with

the launching girder while it is pulled at rear trolley for rotation.




8. Pull the launching girder in the required direction using macalloy bars

provided on the side face of top beam of rear trolley so that launching girder

slides over top beam to the center of rear trolley.

48

9. Put the 100Ø vertical pin passing through the launching girder bottom flange

& the center of the top flange of top beam of rear trolley.

51

Note: In case the holes provided in the launching girder & the top beam flanges does

not match after rotation adjust them by pulling launching girder longitudinally

using the turn buckles provided at the center of top beam of the rear trolley.

10. After horizontal rotation the centerline of Launching Girder should pass

through the center of rear trolley and middle support, the placement of 100Ø

pin will ensure it at rear trolley however at middle support it shall be checked

and rectified if wrong by pulling the cradles using macalloy bar provided in

transverse direction over top of cross beam B1 of middle support.


c/c distance of 1.8m is maintained.


cross beam B1 so that it doesn’t move in transverse direction during

auto launching.

Note: Macalloy bar anchor provided at top of cross beam B1X at rear support shall

remain loose during auto launching so that the cradles are free to move in the

required direction along with the launching girder while it is auto launched

along a curved span.

52

STAGE - 7

53

Step 1 Remove the anchors of rear trolley to allow its forward movement.

Step 2 Remove the 20 bars provided on the sides of Knuckle pins of rear trolley to

allow free rotation of Knuckle pins in vertical plane.

Step 3 Unclamp the anchor plates of longitudinal sliding bearing of middle support &

rear support as shown so that the Launching girder is guided by the rollers

during further auto launching.

(Refer sketch on next page)

Step 4 Remove brakes provided in the middle support & rear support.

Step 5 Start pushing the launching girder using longitudinal movement jack provided

in front of middle support, so that the launching girder slides over the middle

support & rear support & the rear trolley moves along with the launching

girder on rails provided along the erected span.

Step 6 Continue pushing of Launching Girder until the rear trolley reaches close to

the rear support so that the further movement is not possible.

Note: A minimum clear distance of 300mm between rear trolley and rear support

must be ensured

54

STAGE – 8

57

Step 1 Remove anchors of rear support.

Step 2 Lower the jacks of rear support and move rear support using moving trolley

and position it over S-9 segment as shown.

Note: Do not open the jacks of rear support so that it remains inactive during further

auto launching.

Step 3 Anchor the rear support at this location.

STAGE – 9

Step 1 Start pushing launching girder again using longitudinal movement jack

provided in front of middle support so that the front support reaches the next

pier location as shown in the drawing.

Note: Brakes shall be applied at middle support in all conditions where launching

girder is at rest or auto launching has stopped / completed.

58

STAGE – 10

For straight span this stage is not required.

Step 1 For curved span remove the 100 vertical pin passing through center of top

beam of rear trolley and launching girder & rotate the launching girder about

middle support by pulling macalloy bar provided along the top beam of the

rear trolley so that the launching girder is now aligned along the chord of next

span to be erected.

PROCEDURE FOR HORIZONTAL ROTATION

1. Ensure cantilever of length equal to (Span to be erected + 4.250) in meters

measured from centerline of middle support to front end of launching girder.

2. Apply brakes at middle support. {Incase the holes provided in monorail and

braking system does not match the launching girder shall be auto launched

forward by few millimeters (Less than 100mm)}

3. Ensure that the Rear Trolley, Rear Support & Middle Support are properly

anchored at their respective positions.

4. Ensure that the Front Support telescopic leg is closed to its minimum so that

there is no possibility of clash between brackets / projections in bottom beam

of the front support & the pier segment of the already erected span & the shear

key provided at the pier cap during rotation.

5. Loosen the vertical Macalloy bars connecting the launching girder with top

beam of the rear trolley

Note: Do not remove the channels provided below top beam for anchoring unless it

is required to cross the knuckle pins.

61


cross beam B1 so that it doesn’t get pulled during rotation process.



7. Clamp the anchor plates of longitudinal sliding bearing of middle support as

shown.

(Refer sketch shown in stage 6 of auto launching)

8. Loosen the macalloy bar anchor provided at top of cross beam B1X at rear

support so that the cradles are free to move in the required direction along with

the launching girder while it is pulled at rear trolley for rotation.



9. Remove the 100Ø vertical pin passing through the launching girder bottom

flange & the center of the top flange of top beam of rear trolley.


11. Pull the launching girder in the require direction using macalloy bars provided

on the side face of top beam of rear trolley so that launching girder slides over

top beam to attain the required position.

12. Unclamp the anchor plates of longitudinal sliding bearing of middle support as

shown so that the Launching girder is guided by the rollers during further

auto launching.

(Refer sketch shown in stage 7 of auto launching)

Note: No auto launching shall be done after side shifting of the Launching Girder at

rear trolley

62

Step 2 Rotate the Launching girder vertically to ensure that acceptable heights at all

supports is achieved before anchoring the front support

Note: Refer detailed procedure for vertical rotation from annexure A.

63

STAGE - 11

Step 1 Open the telescopic leg of the front support so that the bottom beam of front

support rests over the concrete pedestal as shown in the drawing.

Step 2 Anchor the front support over pier cap by tightening anchor bolts in the

sleeves provided in the pier cap.

Note: Refer detailed procedure for lowering / raising of bottom beam/ telescopic leg

of front support from annexure C.

STAGE – 12

Step 1 Open the jacks of rear support & ensure that it experiences a minimum

reaction of 10tonnes (total reaction on four jacks) on it.

Step 2 Apply brakes at rear support using braking assembly provided at rear side of

the rear support.

Step 3 Tighten the vertical macalloy bars provided at top beam of rear trolley to

ensure that there is no possibility of relative movement between top beam of

rear trolley & launching girder during erection of next span.

Step 4 Move slider beams forward for the erection of next span as shown in the

drawing.

65

4.0 STAGES OF ERECTION OF SPAN

4.1 General

This section gives a general guideline for erection of precast segments in

various spans.

This section is divided in two parts.

4.3.1 This part gives a detailed description for erection of 31.0m span and

4.3.2 This part gives the sequence of erection of segments in all spans

assuming that the general procedure for lifting of individual segment shall

remain same as that detailed out for 31.0m span.

4.2 List of Drawings

Drawing no. Title

LG/15 Scheme for Erection of Precast Segments

(Sheet 1 of 2 & Sheet 2 of 2)

68

4.3.1 ERECTION PROCEDURE FOR 31.0M SPAN

STAGE – 1

Step 1 Move all the slider beams towards the span to be erected as shown.

Note: Only number of slider beams required for the erection of the span shall be

moved

CHECK LIST BEFORE ERECTION

1. All Supports are properly anchored with the span erected/pier cap.

2. Supporting jacks of middle & rear support are locked using lock nut provided

in the jacks.

3. Brakes are applied at middle support using braking assembly provided at their

rear side.

4. The Launching Girder is anchored to the top beam of rear trolley using four

no. macalloy bars provided.

5. Middle support cradles are anchored using the Macalloy bars provided over

the cross beam B1 so that it doesn’t move in transverse direction during

erection of precast segments.

69

STAGE – 2

Step 1 Position the trailer having precast segment S-1 between the spans to be erected

in such a manner that the center of segment to be erected lies as close as

possible to the fixed mounted hoist while looking at it from top of launching

girder.

Step 2 Attach the lifting beam hanging from the fixed mounted hoist to the

Temporary Prestressing beams attached to the segment at sofit level.

Note: Temporary Prestressing beams will be vertically stressed at casting yard

before its delivery at site for erection.

Step 3 Lift the segment slightly & rotate it to the required direction for erection.

Step 4 Lift the segment up to the required height i.e. maintaining a distance of 3.5m

between sofit of launching girder & the top of crown of the segment.

71

STAGE – 3

Step 1 Attach the suspenders through wire rope assembly of first slider beam to the

temporary prestressing beams at sofit level of the segment.

Step 2 Slightly lift the suspender by monojacks.

Procedure For Transferring The Weight of Segment From Hoist To Suspender Bars

1. Lift the suspenders by monojacks and transfer a force of not more than

0.5tonne per suspender in order to remove initial slackness in the suspender

bars.

2. Release the weight of segment from the fixed mounted hoist so that the weight

is transferred automatically on the suspenders of the slider beam.

Note: It shall be monitored that the slider beam remain in contact with both the flats

provided on top of the Launching Girder i.e. there is no uplift (uplift is an

indication of load getting transferred on one suspender slightly more than the

load getting transferred on the other).

In case of uplift, raise the hoist and release the suspenders and check the slider

beam and suspenders carefully for the possible reasons and rectify them and

then repeat the procedure 1 and 2.

3. After transferring complete load from the fixed mounted hoist to the

suspenders remove the pins connecting the lifting beam and the Temporary

Prestressing beams.

Step 3 Raise the lifting device (Lifting Beam) so that it does not obstruct the

movement of slider beam while the segment is shifted to its required position.

Step 4 Move the first slider beam along with the suspended segment to the position as

indicated.

73

Step 5 Line and level S-1 as per latest G.A.D. of Alignment for the concerned span.

Step 6 Lock the slider beam in this position using removable brackets provided for

locking (refer details from Drg. No. LG/04 and Sketch No. LG/SK-1).

Step 7 Secure the position of the segment by placing wooden packing in the gap

between segment and shear key.

74

STAGE – 4 TO STAGE – 6

Step 1 Repeat steps of stage 2 & stage 3 with segments S-1, S-2, S-3, S-4, S-5, & S-6,

one by one, so that the segments from S-1 to S-6 are erected as shown.

Note: The correct position / alignment of segments S-2 to S-6 shall be ensured by

dry matching S-2 with S-1, S-3 with S-2 and so on in the sequence of their

erection.

STAGE – 7

Step 1 Move remaining slider beams towards segment S-6 as shown.

STAGE – 8

Step 1 Lift the pier segment S-11 exactly in the same manner as the earlier segments

& position it with the respective slider beam as near to the shear key as

possible, as shown.

Note: Do not pack the segment S-11 with the shear key

STAGE – 9

Step 1 Lift the segment S-10 exactly in the same manner as the earlier segments &

park it over S-11 segment as shown.

Note: Maintain a minimum vertical gap of 100 mm between segment S-11 and S-10

76

STAGE – 10 TO STAGE – 11

Step 1 Lift the segments S-9 & S-8 & S-7 in the similar manner as done in earlier

cases & positions them as shown.

Step 2 Dry match segment S-6, S-7, S-8 & S-9.

Step 3 Lower the segment S-10 and dry match with the segment S-9

Step 4 Dry match segment S-11 with S-10

Step 5 Check the levels and alignment of span

Step 6 After ensuring correct alignment shift the segment S-11 and S-10 by 100mm

and 50mm respectively toward shear key

Step 7 Lift segment S-10 ensuring a vertical gap of 100mm (minimum) between

segment S-10 and S-11

Step 8 Shift segment S-2 to S-9 by 300mm toward S-11 so that a gap is created

between Segment S-1 and S-2 for gluing.

83

STAGE – 12

Step 1 Apply epoxy glue between segment S1 To S2

Step 2 Do Temporary Prestressing of the segments S-1 & S-2 by Macalloy Bars.

Note: After temporary prestressing a gap of 300mm will be automatically created

between segment S-2 and S-3.

Step 3 Repeat the step – 1 & step – 2 up to segment S-9

Note: Epoxy shall be applied on both surfaces to be bonded as per the instructions of

the supplier.

STAGE – 13

Step 1 Apply Epoxy glue on remaining segments i.e. surfaces between S-9, S-10 and

S-11 simultaneously.

Step 2 Lower the segment S-10 by vertical suspender of sliding beam and position it

close to segment S-9.

Step 3 Shift the segment S-11 close to segment S-10.

86

STAGE – 14

Step 1 Do Temporary Prestressing of segments S-9 To S-11 by macalloy bars one by

one.

Note: The entire procedure of lowering of segment S-10 and subsequent shifting of

S-10 and S-11 for closing the gaps and the Temporary Prestressing shall be

done with in the open time of the Epoxy adhesive to be used as per the

supplier’s manual for application of Epoxy adhesive.

STAGE – 15

Step 1 Insert Prestressing tendons and install their anchors.

Step 2 Do Longitudinal Prestressing of entire span.

STAGE – 16

Step 1 After Prestressing load is transferred on temporary bearings.

Step 2 Release the suspenders & remove the Temporary Prestressing beams.

Step 3 Move the sliding beams towards the counter weight side.

Step 4 Launching Girder is ready for Auto Launching.

89

4.3.2 ERECTION SEQUENCE OF PRECAST SEGMENTS IN DIFFIRENT SPANS

General procedure for lifting of segments remains same for all the spans. However in span of

smaller length, only number of segments and their sequence for erection changes.

Erection Sequence of Precast Segments For 31m Span

Total number of Segments = 11 (S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, S11)

STAGES

1. Move 11 Sliding beams towards the Front support & Erect Segment S1

2. Erect Segment S2

3. Erect Segment S3

4. Erect Segment S4

5. Erect Segment S5

6. Erect Segment S6

7. Move remaining 5 Sliding beams towards the Segment S6 then Erect Segment S11 &

position it near shear key as possible

8. Erect Segment S10 & park Segment S10 over the Segment S11

9. Erect Segment S9

10. Erect Segment S8


93


Total number of Segments = 10 (S1, S2, S3, S4, S5, S7, S8, S9, S10, S11)

STAGES


2. Erect Segment S2

3. Erect Segment S3

4. Erect Segment S4

5. Erect Segment S5

6. Move remaining 5 Sliding beams towards the segment S5 then Erect Segment S11 &



8. Erect Segment S9

9. Erect Segment S8


94


Total number of Segments = 9 (S1, S2, S3, S4, S6, S8, S9, S10, S11)

STAGES


2. Erect Segment S2

3. Erect Segment S3

4. Erect Segment S4




7. Erect Segment S9

8. Erect Segment S8

9. Erect Segment S6

95


Total number of Segments = 8 (S1, S2, S3, S4, S8, S9, S10, S11)

STAGES


2. Erect Segment S2

3. Erect Segment S3




6. Erect Segment S9

7. Erect Segment S8

8. Erect Segment S4

96

Erection Sequence of Precast Segments For 20.5m Span

Total number of Segments = 7 (S1, S2, S3, S6, S9, S10, S11)

STAGES


2. Erect Segment S2

3. Erect Segment S3




6. Erect Segment S9

7. Erect Segment S6

97

5.0 MANUAL FOR ERECTION OF FIRST SPAN

5.1 GENERAL

The erection of precast segments for the construction of superstructure

requires segments to be lifted by the Launching Girder, however while

erection of first span there is no permanent platform available for the

Launching Girder to stand, therefore a temporary structure is required initially

to support the Launching Girder for the erection of first span.

This section is an attempt to enumerate step-by-step procedure of erection of

Launching Girder for first and second span and the superstructure required for

the movement of Launching Girder.

To simplify the process detailed drawing sketches showing position of

launching girder and its accessories have been shown along with the detailed

step by step procedure.

5.2 LIST OF DRAWINGS

Drawing no. Title

215/LG/22 ERECTION SEQUENCE OF LAUNCHING

(SH. 1 OF 3 TO SH. 3 OF 3) GIRDER BETWEEN PIERS 122 TO 123

98

5.3 ERECTION OF LAUNCHING GIRDER IN FIRST SPAN

This section gives a series of sketches showing various stages of Launching

Girder and corresponding condition of erection of span.

The complete erection of Launching Girder includes erection of Launching

Girder and Three spans. It shall be understood that once the Launching Girder

is fully erected then it is capable of auto launching and erecting the spans in

continuation as explained is section 3 and section 4 of this manual.

The scheme has been covered in 23 Stages covering all possible conditions

encountered in the process.

Note: It is important to note that the scheme for Erection of Launching Girder

Between Piers 122 To 123 is specifically meant for erection of Launching

Girder between piers 122 to 123 and the same can not be applied as it is for

initial erection between any other pier combination for which detailed

drawings will be developed separately as and when required.

99

6.0 REFRENCES

Detailed manual of supplier for different items shall be referred for their

operation

123

Annexure A

PROCEDURE

FOR

VERTICAL ROTATION

124

A.1 GENERAL

For spans with no change in gradient the vertical rotation is not required so

that the height of various support shall be 3.5m each measured from top of

crown of the segment to the bottom of Launching Girder.

Note: Height front support will be 5.2m from top of pier cap to bottom of Launching

Girder.

For change in gradient following procedure shall be followed.

125

A.2 Detailed description of various conditions of launching Girder in vertical

grade & corresponding height adjustment of its supports

Direction of Launching

Front Middle Rear RearSupport Support Support Support

Grade g1% 5.6m Grade g2% Grade g3%

Span to be Erected Newly Erected Span

A.2.1 Down Grade

The Launching Girder is said to be moving on down grade if > 0 or grade g 1% < g 2%

(with +ve / -ve signs considered)

Procedure

1. Reduce the height of middle support & try to achieve the required height at

Front Support.

Note: The minimum height to kept at middle support shall be 3.4m however in odd

conditions it can be reduced to 3.35m.

2. If the required height is not achieved raise the height of rear trolley.

126

A.2.2 Up Grade

The Launching Girder is said to be moving on upgrade if < 0 or grade g 1% > grade 2%

(with +ve / -ve signs considered)

Procedure

1. It is required to reduce the height of rear trolley however during auto

launching the Height of rear trolley has to be kept 3.5m deliberately which

happens to be its minimum possible height therefore this operation in not

required.

2. Raise the height of middle support to achieve the required height at front

support.

A.3 Permissible range of height to be ensured at front support

Minimum height* - 3.35m (measured from top of crown of the segment to the bottom of

Launching Girder)

Or 5.05m (measured from top of pier cap to the bottom of Launching

Girder)

Maximum height** - 3.7m (measured from top of crown of the segment to the bottom of

Launching Girder)

Or 5.4m (measured from top of pier cap to the bottom of Launching

Girder)

*Minimum height for inserting middle support during further auto launching

**Maximum length of suspenders available for erection of segments

127

A.4 Calculation Of Height At Front Support For A Known Height At Rear

Trolley And Middle Support

A.4.1 Down Grade

Assuming following data for sample calculation

Span to be erected = S1 = 25m

Span already erected = S2 = 25m (over which Launching Girder is resting at Present)

Grade g1 = + 1.3% (The height of structure is increasing in the direction of launching)



Grade g1% < Grade g2% therefore the launcher is moving on down grade

Height at rear trolley = 3.5m (assumed)

Height at middle support = 3.4m (assumed)

Distance between middle support & rear trolley

= 64.75 - *4.45 - **2.5 - ***(25 + 1.8)

= 31.0m

*Cantilever Distance beyond center line of rear trolley

**Cantilever Distance ahead center line of front support

***Distance between center line front support & middle support

128

Grade of Launching Girder

Top of Crown of Segment

Newly Erected

Span

Bottom of

Launching Girder

Direction Span to be

Of Erected

Launching

a

b

c

d

X

0.9m

0.9m

CL Pier

CL Pier

CL Pier

FrontSupport

MiddleSupport

RearTrolley

Grade g1%

Grade g2%

Grade g3%

129

a = [ 31 - ( 25 - 0.9 ) ] x 2.5 = 0.1725m

100

b = ( 25 - 0.9 ) ] x 2.4 = 0.5784m

100

c = Height of Middle Support – (Height of Rrear Trolley – a - b)

= 3.4 – (3.5 – ( 0.1725 ) – ( 0.5784 ))

= 0.6509 m

Grade of Launching Girder = 0.6509 X 100 = 2.09968%

31

Height of Front Support

X = Height of Middle Support – D + ( Span + 1.8 ) x Grade of Launching Girder

100

d = 0.9 x Grade g2 + ( Span ) x Grade g1

100 100

= 0.9 x ( 2.4 ) + ( 25 ) x ( 1.3 )

100 100

= +ve 0.3466m

x = 3.4 – ( 0.3466 ) + ( 25 + 1.8 ) x ( 2.09968 )

100

= 3.616m > 3.35m & < 3.7m ok

Height of Front Support = 3.616m

For Height at Middle Support = 3.400m

And Height at Rear Trolley = 3.500m

On the same lines the heights at front support, middle support & rear trolley can be

calculated for any span.

130

A.4.2 Up Grade

Assuming following data for sample calculation

Span to be erected = S1 = 25m

Span already erected = S2 = 25m (over which Launching Girder is resting at Present)

Grade g1 = - 1.3% (The height of structure is decreasing in the direction of launching)



Grade g1% > Grade g2% therefore the launcher is moving on up grade

Height at rear trolley = 3.5m

Height at middle support = 3.6m (assumed)

Distance between middle support & rear trolley

= 64.75 - *4.45 - **2.5 - ***(25 + 1.8)

= 31.0m

*Cantilever Distance beyond center line of rear trolley

**Cantilever Distance ahead center line of front support

***Distance between center line front support & middle support

131

Grade of Launching Girder

Top of Crown of Segment

Newly Erected

Span

Span to be

Bottom of Erected

Launching Girder

Direction

Of

Launching

a

b

c

d

X

0.9m

0.9mFrontSupport

MiddleSupport

RearTrolley

CL Pier

CL Pier

CL Pier

Grade g1%

Grade g2%

Grade g3%

132

a = [ 31 - ( 25 - 0.9 ) ] x ( -2.5 ) = -0.1725m

100

b = ( 25 - 0.9 ) ] x ( -2.4 ) = -0.5784m

100

c = Height of Middle Support – (Height of Rrear Trolley – a - b)

= 3.6 – (3.5 – ( -0.1725 ) – ( -0.5784 ))

= -0.6509 m

Grade of Launching Girder = -0.6509 X 100 = -2.09968%

31

Height of Front Support

X = Height of Middle Support – D + ( Span + 1.8 ) x Grade of Launching Girder

100

d = 0.9 x Grade g2 + ( Span ) x Grade g1

100 100

= 0.9 x ( -2.4 ) + ( 25 ) x ( -1.3 )

100 100

= -ve 0.3466m

x = 3.6 – ( -0.3466 ) + ( 25 + 1.8 ) x ( -2.09968 )

100

= 3.384m > 3.35m & < 3.7m ok

Height of Front Support = 3.384m

For Height at Middle Support = 3.600m

And Height at Rear Trolley = 3.500m

On the same lines the heights at front support, middle support & rear trolley can be calculated

for any span.

133

Annexure B

PROCEDURE

FOR

MOVEMENT OF

MIDDLE SUPPORT / REAR SUPPORT

USING MOVING TROLLEY

134

Annexure C

PROCEDURE

FOR

RAISING / LOWERING OF

TELESCOPIC LEG / BOTTOM BEAM

OF FRONT SUPPORT

138

REFER AUTOCAD FILEREFER AUTOCAD FILE

FOR SKETCHESFOR SKETCHES

ON BLANK PAGES OF THE BOOKLETON BLANK PAGES OF THE BOOKLET

142

method stat ijm launch

Documents

erection of launching

details of launching

launching of segmentsdocument

erection procedure

main box girder

rear trolley

maximum span length

list of drawings