Ahmedabad (Gujarat) [India], January 29 : A 100 m long steel bridge has been successfully completed over the underground metro tunnel in the Ahmedabad district for the Mumbai-Ahmedabad Bullet Train project. This marks the 13th steel bridge completed in Gujarat, out of the 17 planned for the project in the state.
In the Ahmedabad district, the Bullet Train viaduct is being built using span-by-span structures with spans ranging from 30 to 50 metres. However, at this location, the alignment passes over the underground metro tunnel connecting the Kalupur and Shahpur metro stations.
As per the release, to ensure that no load from the Bullet Train structure is transferred to the metro tunnel, the foundations were kept well away from the tunnel. This required increasing the span length to about 100 metres. As a result, the superstructure configuration at this stretch was redesigned from an SBS viaduct to a Steel Truss Bridge, ensuring structural safety for both the Bullet Train corridor and the metro infrastructure.
The release stated that the bridge was assembled at a height of 16.5 m above ground on temporary trestles at the site. After assembly was completed, the temporary supports were carefully dismantled, and the bridge was lowered and placed precisely on the permanent support system to ensure safety and structural accuracy.
Weighing 1098 metric tons, the steel bridge is located parallel to the Ahmedabad Sabarmati main line of Western Railways. The structure measures 14 meters in height and 15.5 meters in width. It was fabricated in a workshop in Wardha, Maharashtra, and then transported to the site by trailers.
To facilitate assembly of the main structure, a temporary platform measuring 11.5 x 100 meters was constructed on site. The bridge is constructed with approximately 45,186 Tor-Shear Type High Strength (TTHS) bolts, coated with the C5 system protective paint, and equipped with elastomeric bearings for enhanced durability.