Stability Analysis of Failed Slope in Tindharia Region, West Bengal, India — A Case Study

Abstract

The present study provides a discussion on landslide event which occurred along Hill Cart road, in the year 2011. The concerned area, situated in the Tindharia region of West Bengal, is famous as a UNESCO world heritage site and draws tourists owing to the famous toy train operated by the Darjeeling Himalayan Railway. This paper presents a description of the events associated with the catastrophic landslide which resulted in the abrupt halting of the operations of the toy train network and disruption of road traffic. Observations made during the site visit are presented, summarizing the important geological findings. Data collected during the site visit is utilized to identify the probable failure surface. Back analysis is attempted using the limit equilibrium method, to assess the effect of geomechanical parameters on the stability of the slope while replicating the probable range of parameters leading to instability. The results of the back analysis are further utilized in a finite element numerical model to assess the stability of the new slope profile. Measures for improving the stability of the new slope by incorporation of rock bolts are discussed. It is believed that the findings of the present study will be beneficial for future stability analyses at the concerned site.