Assessment of Vulnerability of Rock Slope Considering Material and Seismic Variability

Abstract

Stability analysis of rock slopes has always been a critical and challenging task for the geotechnical engineering professionals. The complexities associated with the stability analysis arise due to the heterogeneous, anisotropic and variable nature of the rock mass. Assessment of slope stability becomes further challenging under earthquake motions which are random in nature. Thus, uncertainties in both material and loading parameters are required to be considered for a robust assessment of the vulnerability of slopes in geologically complex and seismically active regions. In the present study, the influence of variability in geological properties on the slope stability has been considered within the framework of First Order Reliability Method (FORM). Reliability analysis has been performed for a typical slope profile using the Response Surface Method (RSM) and FORM leading to the identification of critical design parameters along with the quantification of the system performance in terms of reliability index. Subsequently, dynamic time history analyses have been performed for generating the seismic fragility curves of the rock slope as a function of increasing earthquake intensity. Thus, the study attempts to present a methodology for assessing the vulnerability of a rock slope with due consideration of the variation in both the material properties and seismic loading.