Centrifuge modeling of soil slopes overlying bedrock under excavation conditions

Abstract

A number of landslides occur in the soil slopes overlying bedrock due to excavation. However, the excavation-induced deformation and failure behavior and the coupling influential mechanism of the bedrock and excavation have not been clearly elucidated, although they are essential for the stability analysis of slopes overlying bedrock under excavation conditions. In this paper, a series of centrifuge model tests was conducted on the slopes overlying bedrock under excavation conditions with different bedrock shapes. The slopes overlying different bedrocks experienced a significant progressive failure process under excavation conditions, and the slip surface gradually developed from the excavation area at the slope toe to the slope top. The failure mechanism of the slope that overlies the bedrock under the excavation condition can be illustrated by the significant coupling of the deformation localization and failure. There was a shear zone, where the shear strain was concentrated with a substantial increase rate. The displacement direction of the soil in the shear zone was consistent and invariable for a slope overlying the bedrock after the shear zone appeared. Excavation led to a significant influence area inside the slope overlying the bedrock, which was significantly affected by the shape of the bedrock: steeper bedrock corresponded to a wider significant influence area, and flatter bedrock corresponded to a narrower one.