Delhi Metro Milestone: In a major engineering milestone, the Delhi Metro Rail Corporation (DMRC) has successfully completed tunnelling work underneath the operational Red Line corridor at Pulbangash — without disrupting metro services for a single day. The tunnel is part of the Phase 4 extension of the Magenta Line from Janakpuri West to RK Ashram Marg.
The tunnelling was carried out between Pulbangash and Sadar Bazar stations using a Tunnel Boring Machine (TBM), working directly below an elevated viaduct that carries thousands of commuters daily. The Red Line viaduct in this section rests on open foundations with a balanced cantilever span, making the task especially complex and requiring high safety precision.
To protect the existing structure and ensure uninterrupted services, DMRC adopted advanced engineering measures:
Ground Strengthening Around the Red Line Pier
Engineers implemented a Tube-a-Manchette (TAM) grouting programme. A total of 180 boreholes were drilled around the pier to inject high-strength cement grout, strengthening soil conditions, filling voids, preventing ground settlement, and boosting load-bearing capacity.
Real-Time Structural Monitoring
A comprehensive instrumentation network — including settlement markers, deep inclinometers, pier tilt meters, load cells, and automatic total stations — was deployed to track ground movement and pier safety continuously. Expert teams monitored these systems 24/7, with all parameters staying well within permissible limits.
DMRC has completed the down-line tunnel, while work on the up-line tunnel continues with the same precautions. The Red Line carries approximately seven lakh passengers daily, and officials noted that any disruption would have caused major inconvenience to commuters.
The achievement marks another step forward in the Delhi Metro’s Phase 4 expansion, showcasing innovative engineering solutions to build new infrastructure while keeping the city moving seamlessly.
Disclaimer : This story is auto aggregated by a computer programme and has not been created or edited by DOWNTHENEWS. Publisher: ZEE News
