The Static And Dynamic Analysis Of Concrete Gravity Dam Considering The Existence Of Cracks

The existence of the cracks and the depth at the concrete gravity dam heel have some inpact on the static and dynamic characterstics of the dam. Based on the contact model of MARC software, gravity concrect dam is conducted static and dynamic analysis, the impact of different friction models of contact model on the static and dynamic analysis of concrete gravity dam exinsting cracks is focused on; and the nonlinear spring applied in propagation simulation of concrete crack is simply studied; the impact of the presence of cracks on natural frequency of the structural is analysised theoretically with a simple model;and different friction models is applied in the analysis of seismic response of gravity dam, the main contents are summarized as follows:First, the Glue model is applied to do static analysis of the gravity dam and analysis the cracking of dam heel zone, and different friction models of contact model is selected to conduct static analysis the crack exinsting in the dam foundation surface and the dam heel zone, and the impact of different friction coefficients, different contact friction models and different crack length on the results is analsised. The results show that the applying of Glue model in the static analysis of gravity dam is feasible, but the applying in complex cracking problems, such as the rational choice of the separation stress, is needed to further stufy; contact elements can better simulate the open and slip of the cracking of dam heel and response the actual situation of cracks, and the stick-slip friction model and Coulomb friction models have the same impact law on the results, and the results by two friction models have sall difference.Second, the nonlinear spring applied in the propagation of the concrete crack is simply studied, and the nonlinear spring has some advantages in concrete cract propagation simulation, but some problems are needed to furthet studied.Third, the impact of the presence of cracks on natural frequency of the structural is analysised theoretically with a simple model, and the results show that the contact state of the crack has greater impact on the frequency of structure.Four, different friction models are applied in dynamic response analysis of concrete gravity dam, and analysis the impact of different coefficient of friction on the he results. The results show that the stick-slip friction model and Coulomb friction models have little difference on the results of dynamic response analysis, and the different coefficients selected in two frintion model have less impact on the calculation results. At the same time, it is recognized that the the contact model applied in dynamic response analysis of the dam is more complex than in static analysis, and contact parameters and the grid density of the crack zone and son will affect the convergence of computing; setting rational parameters and accuratly considering the dynamic contact characteristics of the crack are needed to further study.