Seismic response of pile-cohesive soil-bridge from shaking table array tests
Hongjuan Chen, Mingzhen Gao, M. Hesham El Naggar, Xiaojun Li, Burak Ozturk, Zhao-Dong Xu, Zhijun Dai, Haojie Xing, Longyun Zhou
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. • Extensive shake table tests were conducted on bridge-pile-soil foundation model employing multi shake tables. • The variation patterns of the natural frequency and damping ratio of the model soil were more complex compared to the bridge and the entire pile-soil-bridge system. • The variations in amplitude recorded by sensors on the piles and in the surrounding soil suggest complex kinematic interaction effects that influence vibration intensity at different locations. • Under the same conditions, the maximum displacement recorded under Tianjin motion was the largest, followed by the El Centro motion, and then the Wolong motion. • The acceleration responses of the system and its components are sensitive to the spectral characteristics of seismic waves.