Study On Seismic Response Of High-Static-Low-Dynamic-Stiffness Three-Dimensional Base-Isolated Nuclear Power Plant

Seismic isolation has been widely used in the fields of industry and civil construction,and it is also effective for improving the seismic capacity of nuclear power plants.However,traditional seismic isolation devices have good seismic isolation effects in the horizontal direction,but they cannot isolate vertical earthquakes and may amplify vertical acceleration.The damage caused by vertical earthquakes cannot be ignored.Therefore,it is necessary to study three-dimensional seismic isolation technology.Three-dimensional seismic isolation technology obtains a good seismic isolation effect by reducing the stiffness and extending the natural vibration period of the original structure,but it will amplify the displacement response of the original structure.The high static and low dynamic isolation system has the characteristics of greater static stiffness and less dynamic stiffness,and can effectively solve the contradiction in vertical seismic isolation.In this paper,combined with the National Natural Science Foundation of China project "Nuclear power plant high-static low-dynamic three-dimensional seismic isolation system dynamic model and seismic response research",the theoretical and experimental research on the isolated CAP1400 nuclear island structure,the work is as follows:(1)According to the proposed design concept of high-static-low-dynamic isolation device,the deformation mechanism of the device is analyzed,and the constitutive model of the device is obtained.According to the mechanical model of the device,the influence of important parameters of the device on mechanical performance is studied.(2)Design a set of the static test device for the proposed high-static and low-motion isolation system,introduce the detailed parameters and test plan of the experimental device,carry out the static test of the device,and compare the experimental results of the device with the theoretical value to verify the correctness of the theory.(3)Establish a single-mass point analysis model for the high-static-low-dynamic isolation system of nuclear power plants to study the impact of key system parameters on the important seismic response of the structure.According to the safety performance design goals of nuclear power plants,the parameter screening and finalization of the device are carried out.(4)Establish a multi-particle rod system analysis model for the high-static-low-dynamic isolation system of nuclear power plants based on the design parameters to study the dynamic response of key nodes of the nuclear power plant,the isolation effect of the nuclear island,the movement state of the device,the limit state of the rubber bearing,equipment safety are studied.