Tehri Hydro Development Corporation Ltd.
Tehri dam is a 260.5 m high Earth & Rock-fill dam. The rocks at the dam site comprise phyllitic quartzties and quartzite phyllite of Chandpur formation which are traversed by numerous structural discontinuities like shears and joints of different orders. To overcome various likely problems of the dam foundation, extensive treatment involving surface as well as sub-surface grouting has been carried out. Detailed geological investigations have been done at the dam site to know exactly the condition of in-situ rocks and the extent of their treatment called for. Major part of the subsurface treatment has been done through underground galleries. In order to minimize any possibility of development and accumulation of pore water pressure in the d/s abutments, the underground galleries on the d/s of dam core are being utilized as drainage galleries.
This paper presents a brief account of the scheme of foundation treatment adopted at Tehri dam.
