Analysis of Rainfall-Induced Shallow Slope Failure

Abstract

Rainfall-induced shallow slope failure has proved to be disastrous in many parts of the world. Majority of slope failures pose a significant risk to infrastructure and public-safety largely due to rainfall-induced slope failures. The stability analysis of slope generally seeks to understand the cause of the slope failure. The penetrating water reduces matric suction within the soil thereby reducing the shear strength of the soil slopes. In this direction, this paper attempted to analyze the slope behavior under different rainfall intensities and at slope angles. A series of numerical analysis was conducted under a fully coupled flow deformation in PLAXIS finite element modeling code. The numerical trials to check the stability of slope were performed under two dissimilar states, (1) rainfall of certain intensity was applied to the slope for a period of 24 h, and (2) the slope stability was analyzed using soil nailing technique. Different rainfall intensities were applied to evaluate the maximum deformation and variation of pore-water pressure of the shallow slope. Results showed that with increasing rainfall duration, slope deformation increased thereby making the slope unstable. In addition, it is observed that the horizontal deformation in case of the reinforced slope gets reduced, hence increasing slope stability.