Probabilistic analysis for excavation stability in spatially variable soil based on upper bound method

The limit analysis incorporated with the random field theorem is an effective approach for the probabilistic analysis of geotechnical engineering stability. A failure mechanism for excavation stability analysis in spatially variable soil, which is combined with random field theory with rotational failure mechanism of excavation is proposed. Random distribution of soil shear strength parameters is readily generated with the proposed approach, thereby enabling efficient and accurate estimation of the failure probability of an excavation. Through an illustrative example, the feasibility of combining random field with rotational failure mechanism is verified. Through several practical engineering cases, the rationality of probability analysis results is verified. Parametric sensitivity analysis is performed with Monte Carlo method to investigate the effects of each factor on the failure probability of an excavation in spatially variable soil. The results show that the proposed failure mechanism of excavation in spatially variable soil provides the reasonable failure probability calculation results for engineering practices.