Seismic Analysis Of Concrete Gravity Dam Based On Fluid-solid Coupling Method

As a traditional dam type,concrete gravity dam is widely used in water conservancy construction because of its many advantages.China is located between the circum Pacific seismic belt and the Himalayan Mediterranean seismic belt,and belongs to the earthquake prone area.Once the dam located in the seismic belt loses stability or structural damage due to earthquake,it will cause great life and economic losses to the downstream area of the reservoir.Therefore,it is particularly important to analyze the seismic safety of the dam.In this paper,based on the seismic research status and finite element analysis theory of gravity dam,taking Zhangjiapo concrete gravity dam as the research object,the seismic analysis is carried out by ANSYS software.The main research contents are as follows:(1)Two typical dam sections of Zhangjiapo concrete gravity dam,overflow and non overflow,are selected to establish the calculation model.The stress and strain of the dam under normal water storage condition are calculated.The stress and strain laws of different dam sections are studied.The safety of the dam is analyzed,and the basic data support for seismic calculation is provided.(2)Aiming at the seismic safety problem of concrete gravity dam,the dynamic calculation is carried out under the condition of normal water storage level.In order to calculate the dynamic response of the dam more accurately,according to the different methods of exerting reservoir hydrodynamic force in the seismic analysis of gravity dam,APDL is used to compile the fluid solid coupling method and the additional mass method to establish the dam reservoir hydrodynamic analysis program,and the modal analysis is carried out for the two working conditions of empty reservoir and normal pool level;finally,the dynamic time history of concrete gravity dam is analyzed by using artificial seismic wave The stress and displacement changes are calculated.(3)The distribution of hydrodynamic pressure and the stress-strain characteristics of Zhangjiapo gravity dam under earthquake are compared between the fluid structure coupling method and the additional mass method.The seismic safety of Zhangjiapo gravity dam is evaluated.The results show that the fluid solid coupling method can fully consider the compressibility of reservoir water and the interaction between reservoir water and dam body,so the calculation results are more accurate and reasonable;Zhangjiapo concrete gravity dam meets the seismic safety requirements of engineering design intensity.The analysis conclusions can provide theoretical basis for the safety analysis of Zhangjiapo dam,and the calculation method has a certain reference value for similar projects.