Riverbank stability study at the University of Alberta, Edmonton

The need for new building sites at the University of Alberta required an investigation of the stability of the valley wall of the North Saskatchewan River within the limits of the campus.A geologic map and stratigraphic sections were drawn which show Upper Cretaceous shales and sandstones overlain by preglacial sands and gravels which, in turn, are overlain by till and glacial lake sediments.A large, buried preglacial valley on the western side of the study area enhances slope stability because it lowers the piezometric surface. Landslide analyses in this area indicate that effective strength parameters near peak values are being mobilized.On the eastern side of the study area old landslides are revealed by subdued slump topography. Residual strength parameters used in an infinite slope analysis result in low factors of safety.