Numerical Modeling of the Columbia Mountain Landslide, Northwestern Montana, U.S.A

摘要

A suite of analyses was performed using SLIDE, FLAC, UDEC, and DDA software to examine the stability of the Columbia Mountain landslide. Investigation of the initiation of failure suggests that although no obvious kinematically admissible modes of failure exist, the strength of the rock mass is controlled by the presence of discontinuities. High groundwater levels and/or seismic loading are sufficient to reduce factor of safety (FOS) values to less than 1.0. Although the FOS of the existing slope is marginally higher than that of the original slope that failed, nearby slopes appear to have equal or lower FOS values and it is not entirely clear why failure was limited to a single location.