Finite element analysis of long-term stress-deformation behavior for concrete-faced rockfill dam

The aim of this paper is to obtain quantitative information of the long-term mechanical behavior of a concrete-faced rockfill dam (CFRD), particularly the effect of rheological deformation on the performance of CFRD. Some numerical simulations have been conducted for a CFRD of a Pumped Storage Power Station in China by ABAQUS finite element code. A modified double-yield surface rheological model incorporating nonlinear strength is applied to describe the long-term mechanical behaviors of the rockfills. The instantaneous plastic deformations of rockfills are determined by the modified double-yield surface model; and the time dependent viscoplastic deformations of rockfills are defined by the empirical equations of exponent function. The predicted results of finite element analysis (FEA) present the evolution of the stress and deformation of dam body, dam element and face slab at the construction, impounding and operational stages. From the results of FEA, it has been shown that the rheological deformation of rockfills at the operational stage has a remarkable effect on the stress and deformation of CFRD. The results or conclusions in this paper are beneficial to further knowledge, reasonable prediction and optimizing design of the long-term mechanical behavior for CFRD.