CASE STUDY of Cantilever Method of Erection RUB spanning mtr. NH-5 (Chennai-Kolkata) PREPARED BY: Srinibas Sahoo, AXEN/C/E.Co.Rly/Cuttack P. Choudhary, AXEN/C/E.Co.Rly/Khurda Road C.V. Naik, ADEN/E.Co.Rly/Srikakulam B.M. Rao, ADEN/S.E.Rly/Bondamunda Srinibas Sahoo, AXEN/C/E.Co.Rly/Cuttack P. Choudhary, AXEN/C/E.Co.Rly/Khurda Road C.V. Naik, ADEN/E.Co.Rly/Srikakulam B.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. 6.2 nd cross girder, Rail bearer.
ERECTION OF FIRST PANNEL
SEQUENCE OF ERECTION CONTD………….. 7. Advance of temporary track & crane. 8. Two diagonal L 2 U Two vertical L 2 U 2, Two dia L 2 U Top chord U 1 U Link connection. 12.Top lateral bracings, Sway bracing.
ERECTIONAL DIAGONAL
SEQUENCE OF ERECTION CONTD………….. 13.Vertical L 3 U 3, Bottom chord L 2 L 4, diagonal L 4 U 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 member 19.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