Influence of material spatial variability on slope stability in soft rock

Abstract

Impacts of material spatial variability usually are not considered in traditional slope stability analyses. However, most geotechnical materials are not uniform inside a slope. The objective of the present study was to evaluate the impact of material spatial variability on slopes in soft rocks. The random field model was used to obtain the material spatial variability. The numerical analyses of slopes in soft rock mass were performed using a distinct element method based program UDEC. After that, Monte Carlo simulation, UDEC, and random field models were used together to analyze the impact of material variability and the slope stability. A series of numerical experiments were performed to understand the effect of joint spacing, joint angle, and size of scale fluctuation (δ). Also, failure types and mechanisms were synthesized and evaluated. The probability of failure became higher as the slope considered horizontal spatial variability of the material. The influence of the horizontal size of δ on slopes without joints was much higher than the slopes with joints. In addition, the slopes with joints yielded fewer failures as δ increased. The results of the analyses could be used for prevention of slope failure, future support system, and geotechnical exploration.