Study On The Seismic Numerical Analysis Of Gravity Dam For Engineering Application

Focus on sustainable development and the western development strategy, the construction of quite a few high dams are in progress in the southwestern region, where is the strong earthquake zone, so seismic safety evaluation of the dam is particularly important. The result of numerical simulation of dam seismic response can provide the reasonable technical basis for seismic safety evaluation. In this paper, for engineering application, we study on the model and the method of solving that is used in the numerical simulation. Then engineering projects are analyzed. The contents of the paper include the following three aspects:(1)Material mechanics method for the static and dynamic analysis has been the fundamental basis for seismic safety evaluation of gravity dam in code of concrete gravity dam design. To simplify the complexity of traditional classical material mechanics method model in dynamic analysis of gravity dam, in recent years, with finite element analysis technology’s increasingly promotion, many beam-mass new model is used in the engineering field, partly replace the role of traditional material mechanics method model, and reflect certain advantages in seismic excitation coupling in multiple directions, also multi-way coupling movement. In this paper, based on the basic definition of material mechanics method, we valuate the result of mode, shear stiffness, displacement on top of dam, as well as internal force using beam-mass model. Then do a detailed comparison between these finite element models. The efficiency of beam-mass model is verified by the comparison, which consistent with the results of traditional material mechanics method, and it can be used in the structure seismic analysis.(2)SRSS is usually used to determine the design earthquake while solving the seismic response of gravity dam by the modal response spectrum method. Gravity dam is generally under axial force and bending moment, and generally we obtain the maximum value of axial force and bending moment that occurs under earthquake. However, the maximum value of axial force and bending moment don’t take place at the same instantaneous, it will be conservative. The envelope method proposed by A.K.GUPTA is a good solution to the problem. In this paper, this method is extended applied to solving the dynamic response of gravity dam. Then carry on dynamic analysis on the beam-mass model established in the previous. Get the more reasonable response result. (3) Contact element is usually used to simulate the structural plane, the interface of dam body and foundation, the layer property of RCC dam. There is no special contact element in ANSYS software. But ANSYS software provides a powerful secondary development tool, so that users can customize and develop their own elements, which may rely on the powerful pre process and post process as well as solution capabilities of standard ANSYS versions to facilitate calculation. In this paper, we make a detailed introduction about the environment and the step of ANSYS secondary development. On this basis, the contact element program is developed and ANSYS secondary development of contact element is realized. Finally, the contact element is applied to engineering projects, the dam body-foundation interface, and the layer property of RCC dam are simulated, and the result is good, which verify the correctness and effectiveness of the element.