Tehri Dam with maximum height of 260.5m is one of the highest rockfill dams in the world. Total quantity of various fill materials placed in the dam is about 27.98 million m3, including the quantity of fill in coffer dam which is a part of the main dam.
A number of innovations have been made at Tehri project in respect of the slope stabilization for the reason that the area had very soft quartzite rocks and were found to be unstable. These measures included deep pile shafts of 3 m diameter, long cable anchors of 30-40 m length and bundled anchors consisting of 7 strands. An abrasion resistant coating called ‘Polyurea Coating’ was applied on the lining of low-level outlet of the project. Further, use of high performance concrete of M-60 grade consisting of silica fume was extensively made at various wearing surfaces exposed to the velocity of more than 25 m/s.
The project was put to operation in Oct. 2005. The dam has not yet shown any sign of abnormal pore pressure build up inside the dam body. The seepage through the dam body and abutments is well within the limits even after 4 years of operation. The settlement in the dam body has also been observed to be much below the prescribed limits.
The project is owned by Tehri Hydro Development Corporation Ltd., India.
