Presentation on theme: "Welcomes to presentation on Segmental Construction by Crib & Crane and Crib & Goliath Gantry at National Seminar on Design & Construction of Bridges Welcomes."— Presentation transcript:
Welcomes to presentation on Segmental Construction by Crib & Crane and Crib & Goliath Gantry at National Seminar on Design & Construction of Bridges Welcomes to presentation on Segmental Construction by Suspended and Under Slung Launching System at National Seminar on Design & Construction of Bridges
Joint venture of Govt. of India and Govt. of Karnataka. First phase 33KM sanctioned in 2006 and extension of 9.3 km in 2010. Elevated corridor is 33.5KM long and Underground is 8.8 KM long. Foundations mostly on piles and very few open foundations. Segmental PSC Box type Super structure adopted. About Bangalore Metro
Bangalore Metro of 42.3 km consists of two corridors – North South corridor – Puttenhalli to Hesaraghatta cross- 24.20kms East West corridor - Bayappanahalli to Mysore road terminal- 18.10kms In both the corridors except underground corridor around Majestic all are elevated Elevated Corridor total length – 33.48Kms Total Stations – 33 Under Ground Corridor length – 8.82kms Total Stations – 7 At grade – 2 No of Elevated reaches – 7 (R-1, R-2, R-3, R-3a, R-3b, R-4 & R-4a) Gauge – Standard Gauge – 1435 mm (Double Track) No of Coaches per rake – 6 Motive Power – 750 V – DC, Through Third Rail bottom collection shoe System Automatic Train Protection, Automatic Train Operation, Automatic Train Supervision Estimated Project Cost – Rs 11,609 Crores Introduction
From Baiyyappanahalli to Cricket Stadium – 6.7 Kms Total No of Stations – 6 Nos Total No of Piers – 209 Nos Total No of Cast in situ Spans - 3 Nos, Two 50 m & one 28m Total No of Segmental Spans – 201 ( 22m - 11 nos, 25m - 57 Nos, 28m - 125 Nos, 31m - 8 nos. Excluding Stations) General Data- Reach 1
Sharpest Curve in Launching done – 120 m Radius ( First time in India) Max Gradient in Launching done – 1 in 25 (4%) Max Pier Height in Launching done – 15m Bearing – Elastomeric Type for span up to 31m & POT cum PTFE for 50m spans Seismic Arrester – Shear Key Device with shear bar & vertical bearing stressed at the fixed end (trailing end ) Contractors: M/s Navayuga Engg Co Ltd M/s Gammon India Ltd Technical Highlights
Suspended type LG Components Closed Box 2mX2.80mX9.25m, 7nos Spliced together to 64.75m Length Front Support Middle Support/Rear Support Rear Trolley Sliding Beams, Counter Weight – 56 MT Crab Hoist – 80 MT
Suspended type LG Lifting of Segments Segments lifted from the trailer by crab hoist Lifted segments suspended from Sliding Beam by 2nos of HTS bars & slings. Moved to the respective positions by Slider beams
Counter Weight Sliders Rear trolleyRear supportMiddle support Front support Typical View of Suspended type LG
LIFFTING HOIST SLIDING BEAMS SEGMENT S1 MAIN GIRDER REAR TROLLEY REAR SUPPORT MIDDLE SUPPORT FRONT SUPPORT SEGMENT S2
Typical View Suspended type LG – Lifting of Segments
Auto Launching (Movement of LG from Span Erected to Span to be Erected)
. Advantages & Disadvantages Of Suspended Type LG: Preferred for curves of radius more than 300m and Longitudinal slope of 3% Spans up to 37m can be erected with additional box (with 8 box) For erection & Launching, lesser lateral clearance required compared to Under slung System. Auto launching is fast compared to under slung system. Once erected, no ground support arrangements required till dismantling. Occupies less space (9m width). The height of LG is 8m above pier cap. More care has to be taken in working in heights. Not suitable for sharp curves less than 200m radius.
Under Slung LG Launching Gantry - Configuration 1 st time in India a segment launcher with hinge is used Erection of Super Structure –Girder- of Span 31m, 28m, 25m, 22m Erection of Superstructure up to curves of 120 m radius
Under Slung LG Launching Gantry - General Arrangement
Under Slung LG Launching Gantry - Components Closed Twin Box 1.4mX 2.3m x 11.25m,4nos Spliced & Hinged together with nosing to 65m Length “Y’ Frames & Support brackets. Movable Gantry
Under Slung LG Lifting of Segments The Segments lifted from the trailer by gantry running on monorail It is placed on 4 Nos of jacks (25MT) provided on the secondary element beam of LG box
. Advantages & Disadvantages Under Slung LG: This kind of LG is suitable for tackling erection of segments in sharp curves less than 200m radius. Vertical clearance from the ground level will be less as the LG boxes are in the same level of pier cap. Approximately 15 m width will be occupied. More work is involved as there are two different operations, one LG box handling with gantry, other is fixing and re fixing of Y frames to the piers.
Lifted Segments are aligned & dry matched using Gantry & 25 MT jack. Alignment and Gluing Epoxy concrete glue applied on the bonding surfaces at a Pressure of 3 kg/sq cm
Pre Stressing 15.2mm dia 7 ply Low relaxation HTS strands are used Configuration of 19D15 in one cable 10 cables for 28m,31m span & 8 cables for 25m &22m
Pre Stressing Strands inserted with wedges, bearing plates. Stressing force 19.5 MT per strand imparted using hydraulic jacks & power pack.
Grouting of Cables Pressure Grouting of cables is done using cement slurry (W/C ratio – 0.4) mixed with admixture after 24hrs of stressing. Pressure applied 5 kg/sq cm