Himalayan Geology, Vol. 43 (2), 2022, pp. 406-416, Printed in India
Slope Stability Analysis along National Highway-05 (from Karchham Dam to Akpa), Kinnaur District, Himachal Pradesh, India
JAI PARKASH1,2, MAHESH THAKUR1*, T.N. SINGH3, VIRENDER SINGH NEGI4
1Department of Geology, Panjab University, Chandigarh-160014, India
2Geological Survey of India, State Unit: Bihar, Patna-800020, India
3Department of Earth Sciences, IIT Bombay, Powai, Mumbai- 400076, India
4Shongtong-Karchham HEP, Himachal Pradesh Power Corporation Limited, Kinnaur-172107, India
*Email (Corresponding author): mahesh09@gmail.com
Abstract: The present study covers the slope stability analysis of 40 vulnerable landslide zones and road cut slopes along National Highway 05 (NH-05), ~25 km from Karchham Dam to Akpa Bridge, Kinnaur district, Himachal Pradesh, India. Using Continuous Slope Mass Rating the stability of 40 slopes was evaluated, 15 slopes fall into the Class IV category, 11 slopes fall into Class V, 7 slopes fall into Class III and 7 slopes fall into Class II category. The kinematic analysis technique was employed to identify the potential failure modes of the jointed rock slopes. The kinematic analysis demonstrates that wedge failure is the most common and likely failure type amongst the three failures (wedge, planar, and toppling) for all studied slopes.
Basic Rock Mass Rating (RMRbasic) and Geological Strength Index (GSI) are used for the rock mass classification. The basic GSI values for the studied slopes vary from 39 to 57, indicating blocky/disturbed to very blocky rock mass. Observations indicate no correlation between RMRbasic and GSI values for 40 slopes in the study area. Therefore, it is better to employ RMRbasic and GSI separately to understand the jointed rock mass condition of the region.
Keywords: Slope Stability, Kinnaur, Himachal Pradesh, Rock Mass Classification, Continuous Slope Mass Rating, Kinematic Analysis.
