Hyderabad metro rail takes up works on construction of bridges.

The Hyderabad Metro Rail Limited has begun works on the complex segment of metro rail bridge construction in several parts of the rail corridor where metro line crosses the rail network.

With the South Central Railway handing over railway land on temporary lease for a few months to HMRL for assembling and launching the massive steel Metro Rail bridge over the existing Oliphanta railway bridge near Secunderabad station, the L&TMRHL will soon bring the pre-fabricated steel bridge structure from Ghaziabad to Secunderabad for commencing the work on the bridge, NVS Reddy, MD of HMRL said.

Of the 8 metro rail over bridges being constructed in the twin cities, Oliphanta bridge construction is the toughest and an engineering challenge. The railways laid stiff conditions that no metro pillar is permitted in between the tracks and will have to be 28 ft height above the bridge tracks for accommodating future double-decker trains.

The metro rail main obligatory span had to be designed for 275 ft without any support and with a height of 60 ft from road level. Complicating further is the presence of a very sharp 128 mtr radius road curvature. To take care of these technical needs, a specially pre-fabricated high strength steel truss structure with special steel plates and steel bolts and high quality welds is being used for this bridge construction.

The entire steel bridge weighing about 1,100 tonnes was fabricated and assembled at an engineering factory in Ghaziabad with high precision. To withstand the high stresses of different types that will be induced by such a large span and height, the high strength steel plates are joined by HSFG (High Strength Friction Grip) bolts which will provide necessary strength for the bridge.

The so assembled bridge will be dismantled piece by piece at Ghaziabad and brought to Secunderabad by July. Meanwhile, a temporary multi-pillar support structure called “trestle structure” for a length of about 500 ft would be assembled on the leased railway land to support the launching of the bridge.

The bridge construction will be completed by January next year, he added.

HBL