Three-Dimensional Finite Element Simulation Of Pushihe Concrete-Faced RockFill Dam

Concrete-faced rockfill dam is one of the most important hydro-structure. It is primarily made of rockfill and gravel, which is of bearing function. And at the upper side of dam, the concrete face is located, which is of antiseepage function. It receives the widespread attention of its multitudinous merits. The key problem with concrete-faced rockfill dam is the deformation of the dam and the leak caused by the damage of gap in the concrete face. Therefore, the deformation of the dam becomes the core problem in the design of the dam. The refined model is simulated in this paper, based on the actual case of Pushihe concrete-faced rockfill dam, the three dimensional non-linear finite element model is done with large finite element software—ANSYS, and the deformation and stress of the dam is analyzed.The physical and mechanical characteristics of rockfill is analyzed, and the element type and contact element type is determined. According to experiment data and research results, the Duncan-Chang non-linear constitutive model is selected to denote the stress strain character of rockfill, and the rockfill material parameter is also determined. The incremental construction process of rockfill dams was numerically simulated, using "birth and death" element supplied by ANSYS. The numerical simulation results indicate that: in the completion period, the maximal vertical deformation which is located on 1/2 height of the dam is 0.4m, accounting for 0.51 percent of the dam height. The maximum horizontal displacement which is located on 1/3 height of the dam is 0.17m. The maximum stress in y coordinate is 1.39MPa; the maximum third principal stress is 0.14MPa, which shows that the stress in completion period is mainly caused by the self-gravity of the rockfill.The deformations of peripheral joints and vertical joints of the concrete face in different periods are simulated. The contact model between concrete face and rockfill, concrete face and concrete face is done with contact element supplied by ANSYS. The numerical simulation results indicate that: in the nearby river valley, vertical joints are closed; and in the nearby bank, vertical joints are opened. The maximum opening is 2mm; and in the nearby river valley, peripheral joints have the most maximum opening, which is 17.9mm. Finite element simulation results provide a theoretical basis for deformation reserved in completion period and the joint material of peripheral joints and vertical joints.