Mumbai-Ahmedabad High Speed Rail: NHSRCL Erects First Full Span Box Girder To Speed Up Project

National High-Speed Rail Corporation Limited (NHSRCL) has erected first full span pre-stressed concrete (PSC) box girder of 40 metre span in a casting yard in Navsari district of Gujarat.

This 40 metre full span box girder weighing about 970 million tonnes (MT), involving 390 cubic metres of concrete and 42 MT of steel was cast in a single piece without any construction joint on 1 November 2021.

This is also the heaviest PSC box girder in the construction industry of India. To expedite the construction of viaduct for Mumbai-Ahmedabad High Speed Rail corridor, NHSRCL is adopting a full span launching method.

The precast girder was picked up from the stacking yard by the straddle carrier and moved to the predefined location from where it was lifted by the bridge gantry for erection.

This is a technical procedure which requires a high level of precision and expertise. The 40 metres full span girder was then placed between the Pier P11 and P12 of the high-speed corridor. The height of the piers is 13.4 metres from the ground level.

In order to expedite construction of the viaduct, construction of substructure and superstructure has been taken up in parallel. While the work of substructure including 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 machinery over the cast pier caps.

Twenty-three casting yards are being developed along the alignment for casting of full span girders of 30, 35 and 40 metres. Each casting yard is spread in an area of 16-93 acres as per requirement and is located near the high-speed rail alignment.

Planning of casting yards and heavy machinery for launching has been done in a way to meet peak requirements of superstructure casting.

For expeditious casting of girders with quality, facilities like jigs for making rebar cage, casting beds with hydraulically operated pre-fabricated moulds, batching plants, aggregate stacking area, cement silos, and labour camps have been developed in each casting yard.

Mumbai Ahmedabad High-Speed Rail Project (MAHSR) is 508 km long. Out of 508 km, 352 km lies in Gujarat (348 km) and Dadar & Nagar Haveli (4 km) and the remaining 156 km lies in Maharashtra.

Out of 352 km, the civil contracts of 343 km are already awarded. L&T is the executing agency for 325 km length, through two packages awarded to them.