CASE STUDY CASE STUDY of of

Cantilever Method of Cantilever Method of ErectionErection

CASE STUDY CASE STUDY of of

Cantilever Method of Cantilever Method of ErectionErection

RUB spanning 32.958 mtr. NH-5 (Chennai-Kolkata)

PREPARED BY:PREPARED BY:

Srinibas Sahoo, AXEN/C/E.Co.Rly/CuttackP. Choudhary, AXEN/C/E.Co.Rly/Khurda RoadC.V. Naik, ADEN/E.Co.Rly/SrikakulamB.M. Rao, ADEN/S.E.Rly/Bondamunda

Srinibas Sahoo, AXEN/C/E.Co.Rly/CuttackP. Choudhary, AXEN/C/E.Co.Rly/Khurda RoadC.V. Naik, ADEN/E.Co.Rly/SrikakulamB.M. Rao, ADEN/S.E.Rly/Bondamunda

LOCATION

•Bridge No. 4 on Cuttack Paradeep doubling project.

•NH-5 Chennai-Kolkatta spanning

SITE CONDITION•Heart of Cuttack city on NH and Service Road on both side.

•No scope for middle support, and no diversion Road.

•Space constraint

•Track center 8 mt.

•Skew angle – 27 0

•C/C of bridge shifted 6.5 mt. towards Cuttack due to skew angle.

ERECTION OF FIRST PANNEL

WHY CANTILEVER METHOD CONSIDERED

• Multispan.• Insufficient Railway land.• Feeding from one end only.• No traffic block possible.

CHARACTERISTICS OF SCHEME

• Excellent quality of fabrication.• Sequential proceedings.• Overall time consumption is less.• Huge quantity of counter-weight.• Tailor made link material, pin &

buffer block.

EQUIPMENT

• Erection crane -5M/T capacity.• Link, Link plate & Link pin.• Temporary Vertical.• Buffer block.• Temporary Portal.• Hanging device.• Trestle beam.

TEMPORARY ARRANGEMENT

• Laying of temporary track for erection crane.

• Erection of derrick crane.• Temporary track for feeding.• Temporary vertical, top link.• Roller bearing, end cross girder &

buffer block.

TEMPORARY ARRANGEMENT, ERECTION CRANE

ERECTION OF BOTTOM CHORD

PRELIMINARY ARRANGEMENTS

• Counter weight 19 M/T • Roller bearing, end cross girder• Main gusset, Diaphragm, riveting

including countersunk rivets on formation.

• Bearing slab, buffer slab.

COUNTER WEIGHT

SEQUENCE OF ERECTION

1. Roller bearing, end cross girder.2. Bottom chord.3. Bottom Lateral Bracings.4. Vertical.5. End Racker.

6. 2nd cross girder, Rail bearer.

ERECTION OF FIRST PANNEL

SEQUENCE OF ERECTION CONTD…………..

7. Advance of temporary track & crane.

8. Two diagonal L2U1.

9. Two vertical L2U2, Two dia L2U3.

10.Top chord U1U3.

11.Link connection.12.Top lateral bracings, Sway bracing.

ERECTIONAL DIAGONAL

SEQUENCE OF ERECTION CONTD…………..

13.Vertical L3U3, Bottom chord L2L4, diagonal L4U3.

14.Cross Girder, Rail bearer, Bottom Lateral Bracing.

15.Erection crane advanced over link & top chord.

16.Advanced progressively.17.Landing Bottom Chord on bed block over CC

Crib.18.Balanced member19.End Racker

ERECTION OF SECOND PANNEL

LANDING OF THE GIRDER ON BED BLOCK

20.Jacking up the girder.21.Release of preliminary

arrangement.

SEQUENCE OF ERECTION CONTD…………..

PRECAUTION

• Ultra Sonic testing of link pin.• Wire rope, Pulley.• Alert to road user through state

authority.• Full scaffolding, wire net to avoid

falling hot rivet on road.• Fencing by the side existing track.• Round the clock watch man with flag

on Road and Rail.

PROBLEMS ENCOUNTERED

• Problem during piling• Problem during erection• Working on monsoon• No working on rainy day• One way traffic• Shifting of derrick material for

dismantling of errection crane• Dismantling of derrick

CONCLUSION • The method of erection is very useful in multispan

girder• This method needs special equipments • Method is very useful in case of RUB etc.where

intermediate support is not feasible • Needs well trained and experienced staff