Evaluation of pile-soil-structure interaction effects on the seismic responses of a super long-span cable-stayed bridge in the transverse direction: A shaking table investigation

摘要

This paper presents shaking table studies to evaluate the pile-soil-structure interaction (PSSI) effects on the seismic responses and dynamic properties of a large-scale full model of a super long-span cable-stayed bridge with pile groups and site soil in the transverse direction. The dynamic interaction of the bridge full model, including superstructure and substructure, was investigated under earthquake excitations with increasing shaking amplitudes and various frequency contents in the transverse direction. The influences of the artificial soil on the dynamic properties were clarified statistically. The experimental results show that the maximum transverse relative displacements between the pile groups top and shear boxes top significantly increase as the shaking amplitude increase, indicating that a larger shaking amplitude implies a more apparent pile-soil interaction effect. The PSSI effects significantly change with the variation of the frequency contents of earthquake waves. Moreover, the substructure has an obvious influence on the seismic responses of the bridge full model in the transverse direction, accompanied by an acceleration increment in structural components. The seismic demands of the cable-stayed bridge may be underestimated and even misinterpreted to a certain degree when the substructure effects are neglected, which suggests that the substructure effects should be considered in the seismic analyses of cable-stayed bridges.