SHAKING TABLES TEST ON A LONG-SPAN RIGID-FRAMED BRIDGE CONSIDERING SOIL-STRUCTURE INTERACTION

In order to enhance the seismic safety of the bridge, the influence of soil-structure interaction under earthquake excitation should be considered for the bridge-foundation system, especially for the foundation consisting of soft soil. A shaking tables test was performed for a 1∶10 scaled model of a three-span rigid-framed bridge, which systematically investigated the influence of soil-structure interaction on seismic response of the bridge model. The tested results indicate that the peak amplitude and spectrum characteristics of the input ground motion change obviously because of SSI effect. Shear-wave velocity and soil-layer thickness are two important factors affecting SSI effects. The displacement response and strain response of the bridge model are increased when soil-structure interaction is taken into account. The effect varies with the spectrum characteristics of the ground motions and the inherent characteristics of the bridge-foundation system. Meanwhile, the results also verify the effectiveness of the real-time dynamic hybrid testing technique.