Geotechnical Assessment and Slope Stability Analysis in Elk Hill, Ooty Municipality, The Nilgiris, Tamil Nadu, India

This paper assists in comparing geotechnical properties and slope stability of the area at Elk Hill, the Nilgiris District, Tamil Nadu with the landslide prone areas that have grown as a result of rising urbanization and tourist induced environmental pressures. Instability of the slopes in this region has been evident causing frequent landslides. To determine slope profile, soil properties and stability conditions, field as well as laboratory research was done. CFC method was used in establishing the factor of safety (FoS) of all profiles at a given level of saturation. The findings reveal that Profiles 1 and 2 are stable when there is a normal climatic condition but become unstable during moderate and heavy rainfalls. Their factor of safety is greater than one when dry but decreases to less than one when completely wet hence the possibility of failure. The profiles 3 and 4 only have a stability under dry conditions, when in the partially and fully saturated condition, their factor of safety is less than one, and they become prone to failure. In Profile 4 though, the slope is steady, and its factor of safety is greater than one even in saturation.