Slope Stability Analysis under Different Loading Conditions using a Numerical Method (FLAC/Slope 2D)

Slope Stability Analysis under Different Loading Conditions using a Numerical Method (FLAC/Slope 2D)

Lily Gurung1, Manoj Chhetri2

1Civil Engineering Department, College of Science and Technology, Royal University of Bhutan

2Information Technology Department, College of Science and Technology, Royal University of Bhutan

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Abstract

Slope stability analysis is a very important phenomenon which can prove to be significantly relevant for tectonically active regions and the Himalayas. There are various methods that can be adopted to analyze the stability of a soil or rock slope. Some of the methods include the limit equilibrium methods and numerical methods, where one can model the slopes case wise and draw conclusions. Following the background study and thorough literature review, the current study focusses only on the numerical modelling and analysis of a weathered slope, as the numerical methods are more advantageous than the traditional methods. FLAC/Slope 2D is used to model 5 different case wise models to carry out the slope stability analysis, which employs finite difference method and shear strength reduction technique to calculate the factor of safety (FoS) of a given model. Conclusively, after modelling and analysing various cases, it was found that the weathered rock slope with complex geometry subjected to forces like pseudostatic force in the presence of water table have FoS lesser than unity, which is unsafe. However, with the introduction of reinforcements along the slope as mitigative measure, the stability of the given rock slope increases by 45.5% to 49.3%.

Key Words:  slope stability analysis, numerical modelling, finite difference method, FLAC/Slope 2D, factor of safety