Experimental and numerical investigations on transverse seismic responses of soil-cable-stayed-bridge system subjected to transverse near-fault ground motions

Abstract

A soil-cable-stayed-bridge system model with 1/70-scale was built following a 1400 m-main-span cable-stayed bridge. Shaking table tests were carried out to investigate the near-fault pulse effects on the seismic responses and pile-soil interaction of the soil-cable-stayed-bridge system model under far-field and near-fault ground motions with various shaking amplitudes in the transverse direction. The seismic response and pile-soil interaction of the soil-cable-stayed-bridge system model were separately compared between the far-field and near-fault ground motions. Then a three-dimension numerical model was established to represent the experimental result and response variation induced by the near-fault pulse effects. These results showed that the near-fault pulse excitations significantly increased the transverse acceleration and displacement of the girder and tower and dramatically amplified the curvature and strain at the tower bottom as compared to the far-field ground motions, resulting in the tower suffering from more damage. The near-fault pulse effects considerably increased the pile-soil interaction of the tower and pier. Moreover, the numerical model could approximately reproduce the experimental results and take the seismic response variations induced by the near-fault ground motions.