The Delhi Metro Rail Corporation (DMRC) will construct 14 sharp curves in Phase III on its standard gauge metro corridor from Hazrat Nizamuddin to Shiv Vihar in East Delhi.
“Because of the uneven twists and turns in this 25 km elevated corridor, the DMRC is forced to construct as many as 14 curves on this stretch that passes through very congested areas like Trilokpuri, Kalyanwas, Vinod Nagar, I.P. Extension, Anand Vihar, Karkardooma, Welcome, Seelampur, Jafrabad and Maujpur,” a senior Metro official said.
The DMRC has to make dedicated beds in its casting yard for casting of special segments.
These segments are then constructed according to the already defined radius of curvature and then put on the viaduct.
Curves of less than 300 metre radius are considered “sharp curves” in urban rail construction, said the official.
The work of building sharp curves requires a great deal of engineering skills and several factors have to be kept in mind while designing special segments/spans at the concerned turn or juncture.
Further, the DMRC has to construct cantilever piers and portals (supports) at appropriate places to provide smooth transition for the curves, wherever required, to take care of the shifted alignment due to curvature.
In 2010, the DMRC had constructed the sharpest broad gauge curve on its elevated section in Gurgaon near IFFCO Chowk with a radius of 282.05 metre between piers no. 125 to 137 in Phase II.