The Hyderabad Metro Rail work will enter the next phase on Sunday when chief minister N Kiran Kumar Reddy will press the button and symbolically start the hydraulic cranes which will hoist the launching girders onto the pillars.
The event will be held between pillars 18 and 19 opposite Genpact.
The actual lifting of the heavy launching girder and the viaduct segments will be undertaken only at night for safety reasons and after conducting the mandatory tests for a couple of days.
Hyderabad Metro Rail Limited managing director NVS Reddy told reporters here on Saturday that the chief minister would also unveil a plaque and lay the foundation stone for Radial Road No 22 at the Metro Rail’s Uppal depot.
The function will be attended by Union minister for science and technology S.
Jaipal Reddy, Union minister of state for road transport Sarve Satyanarayana, National Disaster Management Authority vice-chairman Marri Sashidhar Reddy and others.
NVS Reddy said precast segmental construction (PSC) method will be used to lay the entire 72-km-long metro rail viaduct in order to minimise the usage of the road space and inconvenience to road users during construction phase.
As of now, 900 PSC segments, each 3 metres long and weighing 34 tonnes, are stacked at the precast yard at Uppal. On an average, there will be about 10 segments to cover a span of 103 ft between two pillars.
Each box-type iron girder will be 112 feet long and 300- tonne heavy. Two hydraulic cranes will be used to hoist it on top of two pillars. The viaduct segments will be mechanically lifted and slung to the girders and moved to their respective positions with the help of tackles and hanger bars. The segments will then be matched to fit into each other to check the correctness of the viaduct profile matching the road conditions and are then separated with the help of top trolleys.
Thereafter, epoxy glue is applied to the surface of the segments fitting into each other and all the segments are joined together.