Seismic response of pile-cohesive soil-bridge from shaking table array tests

Abstract

Shake table tests with a pile-soil-bridge model were conducted on a shaking table array system to evaluate the influence of ground motion characteristics on the seismic response of a section of a bridge. Three ground motions with different earthquake characteristics (El Centro, Tianjin, and Wolong) were used as input to examine their effects on the piled foundation-bridge system. The ground motions were scaled at three intensity levels (PGA: 0.15g, 0.45g, and 0.60g) to investigate the impact of intensity on the bridge model's response. The tests were carried out using an array of four shaking tables arranged in a rectangular configuration. The foundation-bridge model, made of organic glass, was placed in a cohesive soil bed enclosed in a rigid box with dimensions of 3.93 × 3.52 × 1.24 m (length × width × height). The results showed that the pile-soil-bridge response was sensitive to the spectral characteristics of the seismic waves under uniform excitations. The bridge deck exhibited varying levels of acceleration amplification compared to the input motion across different ground motions at the same intensity levels. Differences in motion characteristics also led to significant variations in the acceleration and displacement responses of the piles, pier, and deck.