Study on ground numerical models for floor response spectra analysis of nuclear power plant and their influences

In the framework of numerical model of lumped parameters, a time-frequency domain coupled model of ground is presented and recommended in this paper to analyze the dynamic interaction, which solves the soil dynamic impedance based on the harmonic response analysis and maintains the necessary accuracy in the numerical transformation between time and frequency domains by using continued fraction expansion. The proposed dynamic analysis method can be easily utilized in practical engineering with inhomogeneous soil layers, and can play a positive role in enhancing the associated seismic analysis of nuclear power plants in China. Finally, by taking the analysis of dynamic stiffness of soil and the floor response spectra for a certain 1000 MW Nuclear Power Plant as an example, specific numerical comparison analyses are carried out to study the impact influences for various soil models, in which the numerical precision for the new proposed method is well validated. (authors)