Integrating LEM with FEM through model correction factor method in reliability analysis of spatially variable slopes

Reliability analysis of spatially variable slopes involves repeatedly evaluating the slope stability using a deterministic analysis method such as the limit equilibrium method (LEM) or the finite element method (FEM). The LEM is conceptually simple but requires assumptions on failure surfaces for slope stability analysis. The FEM tends to give a more realistic prediction of slope stability particularly when considering the spatial variability of soil properties, but has higher computational cost. The objective of this study is to combine the LEM and FEM to facilitate an efficient reliability assessment of spatially variable slopes. We adopt the model correction factor method (MCFM) to correct the reliability prediction obtained with the computationally efficient LEM. In the MCFM, an effectivity factor is introduced to push the idealized limit-state surface based on LEM to the more accurate limit-state surface based on FEM. We investigate the performance of the proposed approach in the reliability assessment of a c- slope example considering the spatial variability of the soil strength parameters.