Investigating regional groundwater flow influences on slope stability in unlithified materials

Elevated pore pressures play an integral part in slope failure; however, the nature of the regional groundwater flow regime is often not incorporated in slope stability analysis. This research aims to improve our understanding of how the dynamic nature of the groundwater flow regime exerts control on the regional occurrence of landslides in unlithified materials. An integrated hydrogeological – geotechnical methodology is used to investigate the hydrogeological controls on slope stability in Northeast British Columbia. A two-part approach utilized both a series of steady-state groundwater models developed using SVFLUX to investigate the role of geologic contact geometry and hydrogeological characteristics, and a transient groundwater model developed using MIKE SHE to investigate the role of climate. The analysis of these groundwater results highlights implications of regional and local scale hydrogeological processes on pore water pressures. Several challenges were encountered in regard to investigating processes at fine scale resolution within in a large scale groundwater flow model, and an inability to export unsaturated zone results from MIKE SHE limited the slope stability modeling in SV SLOPE.