Chennai Metro Rail completes engineering milestone at Vadapalani for phase-2

CHENNAI: The Chennai Metro Rail Limited (CMRL) has completed a major construction challenge at Vadapalani for Corridor-4 (Poonamallee to Light House) of the Phase-II project. The work involved building a new viaduct above the existing Phase-I Corridor-2 line.

The new Corridor-4 alignment crosses over the operational Phase-I Corridor-2 at Vadapalani, where the site already accommodates a busy flyover and an elevated metro line.

To integrate the new line, the viaduct was built at a third level, ensuring sufficient clearance for the overhead traction system without disrupting existing traffic and metro operations. An official release said that a major engineering challenge was the presence of a 45-metre obligatory span on the Phase-I corridor at the junction.

Conventional crane erection methods were not feasible due to heavy vehicular movement and the active metro line below. As a solution, the CMRL team adopted a lunching girder methodology to safely position the U-girders across the critical stretch.

“An extended pier cap was designed to support the structure. It measured 23 metres long, 10.46 metres wide and 3.5 metres deep. The pier cap required 470 cubic metres of concrete and weighed about 1,200 metric tonnes. It was built in two months after utility shifting was completed,” the release added.

The Vadapalani Metro Station for Corridor-4 is being built as a three-level structure with a commercial area, concourse and platform. CMRL officials said the work will help link Corridor-4 with the existing network and improve travel along Arcot Road once the line starts operations.