Category: Energy


Series’ Next “Surprise” -The Unexplored Mega Shear in Punatsangchhu-II Dam

Occurrence of too many geological surprises, which were blamed for the big mishaps in the two mega Projects Punatsangchhu – I & II ,intrigues one to investigate if ‘ harping on the geological surprises’ was only a scapegoat for the lack of proper geological investigations done by the Consultants and inappropriate design of rock support measures done by the Designers, who were same for both the Projects.

A Case of ” To Be Or Not To Be A Fit Site For 300m Deep Dam Foundations”

The strata shows small scale, S- shape tight folds and broad warping of the beds at places, indicating that the rock strata has undergone the polyphase deformation in the past leading to development of numerous criss-cross structural discontinuities like joints, shears etc. of different orders. Five prominent and two random joint sets are recorded in the right bank. The foliation is very close to moderately spaced from 2cm to 60 cm and dips towards valley slightly in d/s direction; however rolling of dip is observed at places, there it dips into the hill due to folding and warping. The general topography and gentle natural slopes on the right bank of river are controlled by low and valley ward dipping foliation planes.