Stress-strain analysis and safety evaluation of concrete-faced rockfill dams

Abstract

For concrete-faced rockfill dams with a medium dam height of a pumped storage power station, the gravel overburden of the dam site will be deep and the bedrock of the riverbed will be inclined downstream. Under complex topographic and geological conditions, the deformation control of the dam and the stability of the dam slope will be very important to the safe operation of the dam. Therefore, based on the Tsinghua nonlinear decoupled K-G model of rockfill materials, in this work, we adopted the finite element method for simulating and calculating the stress and deformation characteristics of typical dam sections in the construction and storage periods, and we carried out parameter sensitivity and comparative analyses with the Shen Zhujiang double yield surface and Duncan Chang E-B models. According to the findings, the distribution of stress and deformation of the dam were reasonable and conformed to the distribution law of a rockfill dam built on a slope. The maximum horizontal displacement occurred in the middle of the compressible layer near the downstream, the maximum settlement occurred in the middle of the compressible layer, and the maximum value of the panel deflection occurred at about 1/2 of the dam height. In addition, the dam material modulus exerted little impact on the dam stress but had an obvious effect on the deformation of the dam body and face plate. The stress values of the dam body calculated by the different constitutive models showed little difference. Although the distribution law of displacement was almost the same, the magnitude difference was large. Our research results may serve to be a reference for the stress and deformation analysis and engineering design of concrete-faced rockfill dams.