Stability analysis of an unsaturated pond ash slope subjected to rainfall

Abstract

In the present study, stability analysis of an unsaturated homogenous pond ash slope subjected to rainfall using the limit equilibrium method based n Bishop and Morgenstern-Price methods under steady-state seepage and transient seepage conditions was carried out. Seepage and stability analyses were carried out using SEEP/W and SLOPE/W models, respectively. The factor of safety (FoS) in the case of the unsaturated pond ash slope was observed to be higher than the saturated slope. The effect of slope geometry, rainfall intensity, anisotropy in permeability, and provision of drains on slope stability were investigated. It is observed that with an increase in rainfall infiltration, there was a tendency of surficial failure when the rate of infiltration is higher than the saturated permeability in the unsaturated pond ash slope. The study assumes importance related to the stability of slopes constructed with coal ash in the context of ever-growing requirements of electricity in the country, slope failures due to extreme weather events associated with climate change, and the requirement of sustainable alternatives, theories, and technologies to tackle the coal ash waste produced.