THREE DIMENSIONAL STABILITY ANALYSIS OF ABUTMENTS OF JAMRANI DAM, KUMAUN HIMALAYA

Abstract

A 130 m high dam has been proposed across the Gaula River at Jamrani (29°16'N:79°36'E) in Nainital District of Uttar Pradesh. The site is located in a narrow reach of the river having a core-height ratio of 3.3. The Lower Siwalik exposed at the dam site comprises thick bedded sandstone interbedded with subordinate claystone and siltstone. The right abutment slope controlled by south dipping joints is steeper (50°- 70°) than left bank slope (40°-50°). The stratified Siwalik rocks have been studied in details for assessing the stability conditions in the light of requirement of abutment stripping. The stability under dry, wet and dynamic conditions have been worked out for both the abutments separately. Based on the results the capacity of cable anchors for increasing the over all safety of the slopes, has been worked out. The orientation of cable anchors has been derived based onJointing pattern of the slopes.