Open Access

ARTICLE

Reliability Analysis of Slope Stability Considering Temporal Variations of Rock Mass Properties

Xin Gu², Lin Wang^{1, 2, 3}, Fuyong Chen², Hongrui Li², Wengang Zhang^{1, 2, 3, ∗}

1 Key Laboratory of New Technology for Construction of Cities in Mountain Area, Chongqing University, Chongqing, China.
2 School of Civil Engineering, Chongqing University, Chongqing, China.
3 National Joint Engineering Research Center of Geohazards Prevention in the Reservoir Areas, Chongqing University, Chongqing, China.

∗ Corresponding Author: Wengang Zhang. Email: ; .

Computers, Materials & Continua 2020, 63(1), 263-281. https://doi.org/10.32604/cmc.2020.07535

Received 01 June 2019; Accepted 21 June 2019; Issue published 30 March 2020

Abstract

Temporal variation of rock mass properties, especially the strength degradation due to drying-wetting cycles as well as the acidic wetting fluid (rainfall or reservoir water) is crucial to stability of reservoir rock slopes. Based on a series of drying-wetting cycling and experiments considering the influences of pH values, the degradation degree models of the reduced cohesion c′, friction angle φ′ are developed. 2D stability analysis of the slope is subsequently carried out to calculate the factor of safety (Fs) via limit equilibrium method (LEM) and a predictive model of Fs is built using multivariate adaptive regression splines (MARS), revealing the effect of the dryingwetting cycles and pH value. The reliability analysis by Monte Carlo simulation is performed to rationally consider the uncertainty and the temporal variation of the shear strength parameters of rock mass. Results indicate that the MARS-based model can estimate the Fs accurately. The Fs and the reliability index β decrease with increase of drying-wetting cycles, and the temporal variation of rock mass properties has significant influence on the slope reliability. Overlooking the temporal variation of rock properties may overestimate the Fs and reliability index β in the longer term.

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