To negotiate swanky malls and residential buildings on either side of the Metro alignment along the Mehrauli-Gurgaon Road, the Delhi Metro Rail Corporation (DMRC) has constructed the sharpest of all broad gauge curves on its elevated section near IFFCO Chowk.
The curve has a radius of 282.05 meters. Curves of less than 300 meters of radius are considered ‘sharp curves’ in the urban rail construction industry, a DMRC official said.
Situated between MGF Plaza Mall and the IFFCO Chowk Metro station — from pier no. 125 to 137 — the curve is not only the sharpest of the 15 curves along the 7.05 km Gurgaon stretch of the Central Secretariat–Gurgaon line. It is also sharper than any other curve on the 132-km-long board gauge metro network. About 58 kms of the metro network is on the standard gauge.
According to DMRC officials, the construction on the Gurgaon section of the Delhi Metro took twice the normal time in the sections involving curves, as it had to be done very slowly and carefully to avoid accidents in the adjoining crowded areas.
“Normally, it takes about six days to cast an elevated segment but each segment was cast in 12 days in Gurgaon because of the difficult working and site conditions,” DMRC spokesperson Anuj Dayal said.
“However, we were able to complete the work on time and open the section for trials in January this year.” The 27.45-km Central Secretariat–Sushant Lok (Gurgaon) line is expected to open in June 2010.
DMRC officials claimed the work of building sharp curves requires a great deal of engineering skills and several factors had to be kept in mind while designing special segments or spans at the such turns and junctions.
“We built a special dedicated bed in our casting yard for segment casting. The segments were then constructed according to the already defined ‘radius of curvature’ and then put on the elevated section,” Dayal said.
Cantilever piers and supports had to be constructed at appropriate places to provide smooth transition of the curves.