Slope stability analysis and mitigation measures for selected landslide sites along NH-205 in Himachal Pradesh, India

Abstract

Landslide is the most frequent geo-environmental natural hazard which significantly affect human life and environment. It is the natural hazard when occurs especially in hilly regions mainly along highway corridor, results in obstruction to traffic flow. The road network of a developing country plays a vital role in its overall development. Therefore, it is important to ascertain landslide hazard assessment along roads. In this regard, the study was carried out in middle Himalayan region of Himachal Pradesh, India. The paper describes the investigations carried out on two major landslides, namely Panjpiri and Nalayan occurred at Kiratpur Sahib to Nauni road stretch along NH-205 in Himachal Pradesh, India. The slope failure occurred at Panjpiri was identified as plane failure, whereas at Nalayan it was circular failure. The factor of safety was determined by using Bishop’s method of slices and circular failure charts. For factor of safety calculation of Panjpiri plane failure, six conditions were considered based on physical attributes. Subsequently, the evaluation of slope was designed by reinforcement with rock bolts. While for Nalayan circular failure, soil anchors were designed. Thus, evaluation of slope stability of these two failed slopes were carried out for suggesting appropriate mitigation measures. The results of the study conclude that, with an accurate and well-planned mitigation measures, the severe landslide susceptible sites can be stabilized. Adopting effective engineering mitigation strategies may help the decision makers to choose the appropriate strategies to minimize the landslide hazard.