The construction work for an underground section of the Janakpuri West – RK Ashram Marg corridor, part of the Delhi Metro Phase 4 project, has commenced. According to DMRC, as part of the development work, construction of the D Wall along with the casting of tunnel segments of the 28.92 km long corridor has started formally. The construction work of D Wall at the Krishna Park Extension station of Delhi Metro as well as the tunnel segments shall be utilized for tunneling with TBM on a 1.4 km long stretch between Janakpuri West and Keshopur. Additionally, the stretch which is nearly two km long, will also have the Krishna Park Extension Metro station in between and a 365 metre cut along with a cover open ramp near Keshopur leading to the elevated section, DMRC said.
The corridor between Janakpuri West and RK Ashram Marg Metro comprises of 7.74 km of underground lines in total. According to DMRC, D Walls (known as Diaphragm walls) are structural concrete walls that are built-in deep excavation based projects. Mostly, D walls are utilized at congested sites, where the headroom is restricted, or where the excavation is of a depth. With D walls, the excavated area is secured, following which the construction of the underground station is commenced.
Similar technology has been used for the underground metro stations of Delhi Metro right since Phase 1. At the state-of-the-art casting yard that has been developed at Mundka, these tunnel segments are being cast. DMRC stated that the casting yard would manufacture as many as 2,100 rings for the tunneling work.
According to DMRC, in the month of December last year, this work was awarded on Engineering, Procurement, and Construction basis. Despite various constraints such as shortage of labourers and materials due to the imposition of the nationwide lockdown, the milestone could be achieved on time. For the same corridor, the casting work of u-girders was started on June 24.
The Janakpuri West – R. K Ashram Marg corridor, which is a 28.92 km long corridor, is an extension of Delhi Metro’s Magenta Line. This corridor will come up with a total of 22 metro stations.