Mitigation and management of rainfall induced rockslides along the national highways of Himalayan region, India

Abstract

The research focuses on slope stability analysis and stabilization measures of Dhalli landslide, Himachal Pradesh. Kinematic analysis reveals joints J1 and J2 dip towards the bedding plane causes a wedge failure. Field investigation of the rock slope was conducted using Slope Mass Rating method (SMR) which asses the stability of slopes using a rating schemes of (0–100). The results revealed an SMR value of 45 indicating the slope is partially stable. The strength of the rock materials was estimated using ten core samples through point load test indicating an average failure load of 5.4 MPa revealing rocks are weak to moderately strong in nature. Based on the results from the field investigation and landslide morphometry slope stability of the rockslide has been calculated based on the Mohr–Columb failure criterion using Rocscience software. J1 and J2 has a combined wedge area of 1884 sq. m with an FOS value of 0.9 indicating that the slope is partially stable. A suitable stabilization method was proposed using reinforced wired net mesh with a grid spacing of 15 × 15 cm and shotcrete of 30 cm thickness with as FOS of 1.6 indicating the stability of the slope post-stabilization measure.

Keywords

• dhalli landslide
• slope stability
• kinematic analysis
• rainfall threshold
• swedge