Boundary Effect Correction of the Infinite Slope Model for Saturated and Unsaturated Soils

The infinite slope model (ISM) is a classical method for assessing the stability of
shallow landslides, dating back to the seminal works of Taylor (1948) and Skempton and DeLory (1957). Its simplicity has led to widespread adoption in routine analysis and physics-based landslide hazard mapping. However, the accuracy of ISM is contingent upon the slip surface depth being significantly smaller than its length. When this condition is not met, errors due to slip surface boundary effects can reach up to 50%. In this Technical Breakthrough Abstract (TBA), we report a novel correction term that can be added to the infinite slope model, as presented in Eqs. (2) and (3) of the TBA, to account for the slip surface boundary effects. We validated these equations with a total of 27,231 finite element analyses. This research is significant because the proposed correction will provide a more accurate alternative model for physics-based landslide hazard mapping and routine shallow slope stability analysis.