Pore pressure distributions in brittle translational rockslides

Abstract

In this paper, we systematically study steady-state pore pressure conditions in translational brittle rockslides, with special focus on saturated and unsaturated flow in variably fractured rock masses. The study includes a discussion of critical hydraulic borehole observations in translational rockslides from British Columbia, Norway and the Italian Alps and explains these observations with a generic numerical rockslide model. Most key observations, such as piezometric pore pressure levels at the base of translational rockslides, the location of seepage faces, pressure compartments, perched groundwater flows, and deep groundwater tables can be successfully explained. Open questions relate to the magnitudes of negative pore pressures in the unsaturated zones and the impacts of strong heterogeneity in hydraulic conductivity fields. The impacts of suction and seepage forces on slope stability are discussed.