Dynamic Response Analysis On Nuclear Power Plants On The Thick Overburden Layer

As one of the new clear power, nuclear power has become an important choice to replace the fossil fuels, its energy density is far better than solar and wind power, etc.In Nuclear power engineering, the nuclear island foundation adaptability analysis of is the first step of limited NPP siting.Furthermore, the NPP seismic adaptability analysis of the foundation is the core technology. At present, NPP construction rock-bed condition is gradually reduced, so it is necessary to study dynamic response analysis of NPP on the Thick overburden layer, and provides reference of nuclear power site choice in the future.Creating the finite element model,considering the soil-structure interaction(SSI), soil nonlinear characteristics and the mechanism of earthquake wave input.Calculation process can be sketched:(1)the free field model, only applying Viscous-spring artificial boundary(VSB) at the bottom of the model, using shear lateral boundary (S wave vertical input, lateral vertical constraints; P wave vertical input, lateral normal constraints), and applying the equivalent load at the bottom boundary to realize the earthquake wave vertical input.(2)create whole model of NPP and deep overburden, adopt VSB, the parameters of VSB according to the same height soil model to determine, through free field model to calculate the stress and load to calculate the equivalent load to realize the seismic wave input.Thesis mainly carrying out the work has the following contents:First of all,calculate the two-dimensional soil thick overburden layer free field dynamic response, applying the equivalent linear model to simulate the nonlinear features of soil, compared the results with SHAKE2000 commercial program,verify the method accuracy.And then, Intercept different foundation size and different types of artificial boundary, comparing the peak value and position of floor response spectrum changed rule of the upper structure, to explore the foundation size’s effection, and puts forward the reasonable interception range.Finally, using reasonable size to calculate have thick overburden layer or not separately, comparing two conditions of floor response spectrum.In addition,research the influence of the dynamic response of NPP if the soil initial stress calculation considering weight of NPP or not.