Category: Water

image_pdfimage_print
Embankment with core

Retiring Embankments for Flood Control |Manohar Khushalani

Retired Embankments are constructed at a distance from the river edge behind the existing embankment as a second line of defense. When Retired Embankments are constructed along both sides on high ground, sufficiently away from the river bank, more or less straight and little away from river channel to minimize the risk, they are sometimes called Flood Embankments. This is a very effective system and a neat solution to Flood Control where conventional methods of providing closer embankments are not effective.

Water Issues Between Riparian States : India and Nepal

India can look forward to join hands with Nepal in harnessing the hydropower potential and after fulfilling all Nepal’s internal needs avail surplus hydropower from Nepal to meet its own power demand besides augmentation of river flows in non-monsoon period and considerable flood control benefits in monsoon season.

Water Issues Between Riparian States : India and China

China is the only neighbour, with whom India has geographically shared water resources, but there is no water sharing treaty so far. There seemed to be a great degree of timidity in this matter in the past, but it is changing now. The present government is now asserting itself as it holds national interest above everything else.

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.

Massive rock fall in underground cavern

Chain of Massive Surprises in Two Punatsangchhu Projects – Yoginder Sharma

The Punatsangchhu-II (PHEP-II), a 1020 MW project with scheduled date of commissioning of year 2017 at cost of Rs. 37778 millions, new approved project cost of Rs. 72900 millions ( US $ 1.04 billions), expects further escalationin its cost to Rs. 80000 millions ( US $ 1.14 billions), with already incurred cost of about Rs. 65880 millions, is delayed due to the huge rock mass failure in its underground Downstream Surge Gallery (DSSG), resulting in a huge cavity of about 91m height x 70m length and 45m width in the crown of the DSSG. The Dam foundations had encountered, a thus far unexplored, mega shear of maximum 30m width, cutting across the length all the 4 dam blocks diagonally. The shear zone with its about 35ᵒ to 45ᵒ dip, continued under the foundations to large depths.