Slope stability analysis considering spatial variability of soil properties

In order to investigate the influence of spatial variability of soil strength on the slope stability, as well as the adaptability of probabilistic method for evaluating the slope stability, a new concise Morgenstern-price method was adopted to analyze the slope stability, which considering the spatial variability of soil properties. Orthogonal decomposition was performed to spatial covariance matrix of soil strength by Karhunen-Loève (K-L) expansion, and the Latin hypercube sampling (LHS) method and Cholesky decomposition method were used to optimize the generated spatial stochastic field. Thus, the spatial sample of the soil strength could be determined, which is also named random field. The concise Morgenstern-price method was then employed to conduct the calculation of the factor of safety and the failure probability of the slope. The generated samples were examined to be rational for they were good enough to match the objective function. Results show that the samples can reduce the simulation number greatly compared to the Monte Carlo (MC) method, under the condition that the calculated failure probabilities from LHS method and MC method are close to each other. It demonstrates the adaptability of using LHS method to calculate the failure probability of embankment slope. For a given slope, the results show that neither the factor of safety nor the failure probability can assess the slope safety completely. Only the combined using of these two indexes could be effective enough for the slope safety evaluation.