Seismic Response of Steep Slopes in Cemented Soils

Abstract

Cemented soils are characterized by their ability to stand in very steep natural and man‐made slopes which are prone to sudden failures during earthquakes. Because of the hazard posed by such slope failures in many parts of the world, a program of field observations and finite element analyses was carried out to evaluate the seismic response to the steep slopes in cemented soils. The results indicate that failures of steep slopes in cemented soils will occur in moderate to severe earthquakes. The failures of vertical or near vertical slopes are apparently initiated by tensile failure in the upper parts of the slopes. The failures of moderate (less than 70°) slopes are likely to be slides parallel to the slope. Both types of failure are generally shallow, involving 2 m–5 m of material. Finite element analyses also show that the important parameters con trolling stresses and accelerations in steep slopes are the slope angle, the max imum input acceleration, and the ratio of the natural period of the deposit to the dominant period of the earthquake.