NHSRCL casts first Full Span Pre-Stressed Concrete (PSC) Box Girder of 40 meters Span for the Maharashtra section of the alignment.
PSC Box Girder of 40m span weighs around 970 MT, are the heaviest PSC Box Girder in the construction industry of India. The 40m Span Girder is being cast as a single piece i.e., without any construction joint, involving 390 Cum of Concrete and 42 MT of steel.
To expedite construction of viaduct, construction of substructure and superstructure has been taken up in parallel. While the work of substructure i.e., Pile, Pile Cap, Pier and Pier Cap, is in progress, for superstructure, casting yards have been developed along the alignment to cast Full Span Girders and Segmental Girders so that they can be launched using heavy machineries over the casted Pier Caps.
Most of the Girders for Superstructure will be of Full Span 40 Meter long, however, for locations where there is site constraint, Segmental launching of precast segments will be used. Full Span Girder are preferred over Segmental Girder as Full Span Girder launching progress is up to ten times faster than Segmental Girder launching.
For casting of Girders, 13 casting yards are being developed along the alignment in Maharashtra between Shilphata and Gujarat-Maharashtra border. 3 (2 for Segment casting and one for full span box girders) of them are made operational as of now.
For expeditious casting of Girders with quality, facilities like jigs for making rebar cage, casting beds with hydraulically operated prefabricated moulds, batching plants, aggregate stacking area, cement silos, quality laboratory and workmen camps are being developed in each casting yard.
The full span pre-cast box girders will be launched using heavy machineries like Straddle Carrier, Bridge Launching Gantry, Girder Transporter and Launching Gantry. To ensure continuous supply of girders for launching, the box girders will be cast in the casting yards in advance and stacked in a systematic manner.
Similar technology was used in the Gujarat section of the alignment since April 2021, where substantial progress has been achieved in viaduct construction with 255 km of viaduct construction already completed. Maharashtra section has total 135 km of elevated section which included 4 major river bridges of Ulhas, Vaitarna, Jagani and Kharbao etc., 11 special bridges/crossings over National Highways, DFCC & Indian Railway lines etc., three Bullet Train stations in Thane, Virar, Boisar and 7 mountain tunnels.
