Large-scale shaking table model test on seismic performance of bridge-pile-foundation slope with anti-sliding piles: a case study

Abstract

This study aimed to illustrate the seismic performances of anti-slide pile-reinforced bridge foundations in landslides. Based on the anti-slide reinforcement project at Yousuotun along the Chengdu-Lanzhou high-speed railway under construction, shaking table tests were performed on a double-row anti-slide pile-reinforced bridge foundation and landslide model with a 1:40 similitude ratio. Given that the similitude law was satisfied, seismic waves with different frequencies and acceleration amplitudes were input as base excitations to monitor the responses of dynamic parameters: slope acceleration, earth pressure, and pile strain. The amplification effect of peak ground acceleration (PGA) was analyzed. The landslide thrust distribution characteristics and slope response processes were further studied to verify the seismic design of such bridge foundations in landslide-prone areas. The response acceleration of the slope subjected to seismic loads showed a nonlinear amplification “elevation effect”, “surface effect”, and “geological structure effect”. When the distance between the bridge foundation and the back-row anti-slide pile was small, the pier maintained a relatively large PGA amplification factor and was subjected to strong seismic loads. The landslide thrust was mainly borne by the upper part of the back-row anti-slide piles as its distribution changed from spoon-shaped to bow-shaped. Under high-intensity earthquake events, the load-bearing section of the bridge foundation should be strengthened at the sliding surface. Anti-slide piles can effectively limit the dynamic response of the landslide and weaken the seismic response of the slope. The results of testing this reinforcement are the first results proving that the seismic design of reinforced bridge foundations with anti-slide piles can be reliable.