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The paper describes the recent devastating landslide of Kotrupi, Himachal Pradesh in India which had claimed many human lives and properties along its course on 13 August 2017. This event was the third reactivation of the slide as per data available. The study for this landslide involves a preliminary investigation of the site and comparison of pre- and post-event slope stability analysis. Other than rainfall, the combined effect of differential weathering rate of the debris and soil layers, low material strength, and the presence of a fault zone was found to be the primary cause of instability. The analysis was carried out with the geotechnical investigation and numerical modeling with the help of finite element model-based Phase 2 simulator. The significant findings of this paper include numerical simulation of pre- and post-event slide as stated under unsaturated and saturated condition. The study finds a low factor of safety of the present slope. The unstable condition of the slope may trigger another event of the same intensity shortly. [ABSTRACT FROM AUTHOR]

Evaluation of stability of artificial slopes created due to road construction in the mountainous terrain is very important but often a neglected aspect. The safe execution of road-cut slopes depends upon the level of understanding achieved in defining the engineering behaviour of rock masses with respect to its deformation and mechanical attributes. Understanding the realistic response of the rock mass to excavation of rock strata requires proper analysis related to influence of structural elements on their continuous characterization for facilitating safe and economical development of cut slopes along the road sections. In this paper structurally and non-structurally controlled rock slope classification systems are implemented to undertake comprehensive evaluation of stability of road-cut slopes. The work carried out involves collection of various inputs in form of rock mass and discontinuity characteristics from ten cut slopes along a road section in Kullu area, Himachal Pradesh, India. Rock samples were collected from site and laboratory testing has been undertaken to determine the intact rocks strength. Beside these, the kinematic analysis was performed to illustrate the geometrical relationship between various joint sets and the slope face so as to determine their failure mechanism. Several rock mass classification systems developed for rock slope stability assessment are evaluated for known slope conditions. The stability assessment for all identified cut slopes is compared using slope mass rating (SMR), Q-slope and slope stability rating (SSR) methods. Design charts proposed for various factor of safety values have been utilized to evaluate the stability of studied road-cut slopes. Finally, a slope wise comparison is made between the stable angles predicted by SSR with those recommended by Q-slope method. [ABSTRACT FROM AUTHOR]

The geotechnical assessment, safe design and monitoring of highwalls is one of the major challenges in Indian open pit mines. The aim of opencast mines should be to attain steepest possible slope angle without compromising safety in order to maximize profits. Highwall stability is essential for economical and safe exploitation of mineral during open pit mining. Geotechnical investigations are required to quantify the properties of soils and rocks within the mining horizons. The required minimum safety factor for highwalls is 1.2. Highwall should be monitored during open pit operations. This paper addresses the main elements of pit slope failure, accident statistics, design, and monitoring and pit slope management and also the guidelines for safe design and monitoring of open pit highwalls in India. [ABSTRACT FROM AUTHOR]