Modeling Irregularly Inclined Fissure Surfaces within Nonuniform Expansive Soil Slopes

Abstract

Fissures inside expansive soils play a crucial role in triggering the failure of a slope. However, few methods have been developed to model such irregularly inclined fissures in slope stability analysis. This study will propose a simple but efficient advanced approach to quantify the fissure structures that is based on the random field theory, in which the spatial heterogeneity of soil strength can be represented together. The stability analysis of expansive soil slopes that contain fissure surfaces (FSs) under various inclinations will be performed using the random finite-element method. For each scenario, the factors of safety (FoS) that are obtained by conducting Monte Carlo simulations (MCSs) will be statistically analyzed. The slope failure mechanism for several typical scenarios will be discussed in detail. The findings demonstrate that an expansive soil slope might become vulnerable when the slope angle is close to the inclination of FSs. The FoS that results from a uniform soil slope gives an overestimation of slope stability compared with that obtained from a slope model that contains FSs. In addition, the failure mode evolution of a fissured soil slope is strongly related to the fissure inclination, because the irregularly inclined FSs might directly form part of the potential sliding surface. Except for this effect, slope instability will probably develop along those local regions of weaker soil strength. These results could offer practical suggestions for the design or reinforcement of soil slopes with developed FSs, which could serve as sustainable smart and green life cycle solutions for geotechnical slope systems.