NEW DELHI (Metro Rail News): Shanghai Tunnel Engineering Co. Ltd. (STEC) achieved a significant milestone last week by recording the first cross-passage breakthrough for Package 4 of the Delhi-Meerut RAPIDX (RRTS) project.
Cross-passages are crucial in ensuring passenger safety and enabling efficient maintenance procedures. These reinforced concrete structures are strategically placed at regular intervals, ranging from 250 to 400 meters, depending on tunnel length and soil characteristics between adjacent stations.
They serve as emergency escape routes connecting parallel tunnels, allowing passengers to evacuate in case of unforeseen circumstances. Traditionally, cross-passage construction begins after tunnel construction, aiming to enhance working conditions and maximize efficiency.
In December 2020, the National Capital Region Transport Corporation (NCRTC) awarded the controversial contract for Package 4 of the Delhi-RapidX project to Shanghai Tunnel Engineering Co. Ltd.
This 5.6 km package involves building twin tunnels between New Ashok Nagar DN Ramp – Anand Vihar – Sahibabad UP Ramp and constructing a new station at Anand Vihar.
According to estimates, STEC plans to construct approximately 4-5 cross-passages between Anand Vihar and Sahibabad UP Ramp at Vaishali, with an additional 7-9 cross-passages between Anand Vihar and Ashok Nagar DN Ramp at Khichripur.
The company utilizes hydraulic drill machines and occasionally low-grade explosives to facilitate excavation.
With this recent achievement, STEC has accomplished 6 out of 8 planned tunnel breakthroughs on the main line. The most recent breakthrough occurred at Sahibabad UP Ramp in May 2023, achieved by Sudarshan 4.3.
