A Geological Appraisal of Slope Instability and Proposed Remedial Measures at Kaliasaur Slide on National Highway, Garwal Himalaya

For over six decades Kaliasaur landslide (Lat. 30° 14\u27 30 N, Long. 78° 55\u27 50 E) is a nightmare on the Hardwar-Badrinath road in the Garhwal Himalaya. Located on a sharp bend on the left bank of river Alaknanda, it has emerged as a multi-tier repetitive major landslide, retrogressive in nature. Both surficial and deep seated movements have been monitored. The sliding in the upper layers have been predominantly in the colluvium but where interfaces of quartzite and shale participates, the sliding surfaces have been better defined and discrete. In the present paper, the authors have highlighted the geological, geomorphological and morphometric parameters to diagnose the factors responsible for instability of slope and the magnitude of the problems involved. A scheme of remedial measures which .include modification of existing drainage pattern, timber piling for stitching of debris cover on to the slope, construction of retaining walls and putting back the vegetation on the slope are recommended for control of the landslide