Evaluation of soil spring methods for response spectrum analysis of pile-supported structures via dynamic centrifuge tests

Response spectrum analysis is a linear dynamic method that efficiently determines the maximum response of a structure according to its natural period. It is mainly used as a preliminary design technique in the seismic design of pile-supported structures. In the code for analysis, it models piles using either a frame with a virtual fixed point or a frame supported by a soil spring. However, the virtual fixed-point method cannot efficiently and adequately simulate the natural period during a dynamic analysis such as response spectrum analysis. This study derived a modeling method for response spectrum analysis, which can adequately simulate the dynamic response of pile-supported structures. First, p–y loops were derived by conducting dynamic centrifuge model tests, which were then compared with existing soil spring methods. Consequently, the response spectrum analysis using the Terzaghi elastic spring adequately simulated the dynamic responses of pile-supported structures. •Dynamic centrifuge model testing of pile-supported structure in sand is conducted.•The nonlinear p-y curve is derived considering the soil–pile interaction.•The soil–pile interaction is simulated using the elastic soil spring method.•An appropriate modeling method is derived for response spectrum analysis.