Ahmedabad: The National High Speed Rail Corporation Limited (NHSRCL) has begun casting the first full span pre-stressed concrete box girder of 40-metre span to expedite the construction of a viaduct for the Ahmedabad-Mumbai bullet train project.
The span girder weighs around 970 tonnes and will be the heaviest such girder in the construction industry of India. It is being cast in a single piece, i.e. without any construction joint, involving 390 cubic metres of concrete and 42 tonnes of steel, the NHSRCL said in a statement.
To expedite the construction of the viaduct, the construction of substructures such as pile, pile cap, pier, and pier cap, has been taken up simultaneously. Similarly, for the superstructure, 23 casting yards, each spread in 16-93 acres, have been developed along the alignment to cast the girders. Most of the box girders will be of full span 30, 35 & 40 metres.
The planning of casting yards and heavy machinery for launching has been done to meet the peak requirement of nearly 300 full span box girder casting and launching in a month, which equals almost 12 km of superstructure casting & erection in a month.
The 508-km bullet train project is expected to reduce the travel time between Ahmedabad and Mumbai from seven hours to three hours. Of the 508 km project, 348 km will be in Gujarat, 4 km in Dadra & Nagar Haveli, and 156 km in Maharashtra. However, the project is running way behind schedule due to land acquisition delays, especially in Maharashtra.
Separately, on Friday, the NHSRCL invited bids for tunnelling works for 21 km underground, including a 7 km undersea tunnel between Mumbai underground station at Bandra-Kurla Complex and Shilphata in Maharashtra.