SEISMIC RESPONSES ANALYSIS OF CABLE-STAYED BRIDGE CONSIDERING THE INTERACTION OF THE SOIL-PILE-SUPERSTRUCTURE

摘要

The seismic responses under the action of far-fault and near-fault ground motions of the bridge tower structure of the long-span cable-stayed bridge involving the soil-pile-superstructure interaction are numerically discussed by means of two models of the bottom consolidation of the column and the interaction of the soil-pile-superstructure. The results show that the responses of tower of the cable-stayed bridge correlate well with the interaction of the soil-pile-superstructure and the properties of the ground motions. The seismic responses of the two models have much larger values under the near-fault velocity pulse-like ground motions than those of the counterpart. The frequency of system reduces as the flexibility of structure decreases because of the soil-pile-superstructure interaction; the system may have a negative response under the model considering soil-pile-superstructure interaction relative to the other model in terms of the roof displacement and bottom stress of the tower, however, the result can be opposite from the view of acceleration. Thus, consideration of the soil-pile-superstructure interaction can be meaningful both in theory and reality during the seismic design of long-span cable-stayed bridge structure.