Combined dynamic structure-pile-soil interaction analysis considering inertial and kinematic effects

This study developed a combined dynamic analysis model for analyzing the response of piles when subjected to inertial and kinematic effects under seismic loading. A structure-pile-soil model connected to a shear beam model was established to simultaneously account for both these effects. Centrifuge shaking table testing was conducted on two piles that were partially embedded in dry sand to verify the appropriateness of the model. The two piles in the prototype scale (under a centrifugal acceleration of 80 g) were 36 and 27.8 m long and embedded in a 25.4-m-thick sand layer with a relative density of approximately 80%. The analysis results reveal that the combined model can reasonably simulate the structure acceleration and pile bending responses. The analysis model was further used to explore the influence of ground movement and the contributions of ground movement and inertial effects. Although the ground is stiff, the effect of ground movement is also significant to the acceleration response of the structure. Thus, the magnitude of inertial loading is further influenced, especially when the excitation frequency is near the fundamental frequency of the ground. The contributions of the inertial and kinematic effects are influenced by the excitation frequency and amplitude, in addition to the fundamental frequencies of the structure-pile-soil system and ground.