Dynamic Analysis And Seismic Safety Of RCC Gravity Dam In High Earthquake Intensity

Now with the rapid development of water conservation and RCC dam technology. Some high RCC gravity dams will be constructed in southwest and northwest regions with plentiful water resources and frequent earthquake. The adopted design level of earthquake ground motion reachs to nine degrees in these regions. It is very significant that anti-seismic safety for industrial and agricultural production and the safety of the people's life and property in the large region of downstream under high intensity seismic action. Therefore, In order to study deeply the dynamical characteristics and anti-seismic safety of high RCC gravity dam in high earthquake intensity, Dynamical analysis of the three dimensional finite element method is used. The main works of this paper are as follows:1. the relative theories and methods of dynamical analysis are introduced in this thesis. Briefly described the main problems and the practical engineering measure in seismic study on compacted concrete gravity dams.2. The practical project of JinanQiao RCC gravity dam is simulated. To study the effect of integral RCC gravity dam on anti-seismic safety, Modal analysis is applied to research and compare the dynamical characteristics of single powerhouse dam and powerhouse dam group; we calculate and compare the results of the different models of spectrum and transient analysis, the distribution laws of seismic displacements and stresses in RCC gravity dam are analysed.3. Now there is no criterion to appraise the anti-seismic strength according to the results of the finite element. the combination of the static stresses and the dynamic stresses of spectrum in the extreme stress principle is presented in this thesis. In the light of the principle. we transform the combinational normal stress and shear stress of the dam foundation surface into normal force, tangential force and moment. Then we calculate the stress of the upstream and downstream face by material mechanics method and appraise the seismic strength safety of dams in according to the carrying capacity ultimate strength in specifications for seismic design of hydraulic structures.4. the combination of the static stresses and the dynamic stresses of spectrum in the extreme stress principle and the extreme stabilization principle are presented. according to the combinational results of spectrum in the two principles and the combinational results of transient. We study and discuss deeply the seismic stabilization safety on the dam foundation surface.All of work of this paper is combined with the practical project and the research conclusion provide the practical reference to the design and similar projects. At the same time, dynamic response of the high RCC gravity dam is very complex in high earthquake intensity, the problems for further research are pointed out in dynamic analysis.