Development of an interface model based on hyperbolic hardening rule and contact effect analysis of earth rockfill dam

Abstract

Close attention was paid to contact effect between dam body and dam foundation of high earth rockfill dams. A soil–bedrock interface model is developed based on hyperbolic hardening rule of coarse-grained soil and the stiffness matrix is derived in the framework of elastic–plastic interface model. Agreement between the numerical and experimental results confirms the capability of the proposed model in predictions of shear sliding behaviour of different granular soils–structure interfaces. Taking Rumei high core-wall dam as a case, the interface model is embedded in FE program to analysing contact property of interface between dam body and dam foundation. The shear displacement of middle part of contact zone is significantly larger than edge zone and maximum shear displacement of the steep contact band is larger than that of slightly inclined. As for arching effect, setting contact zone has a certain effect on the arching effect of core wall. Considering contact effect makes it difficult for the vertical stress of the core soil material to be transmitted to the surrounding rockfill materials. These works expand soil–bedrock interface model and favours deep understanding of the contact effects between rockfill dam and bedrock, which also guide 3D calculation of earth rockfill dam project.