Shaking table test research on short-distance side-piercing bridge piles in tunnel structures

More and more projects of underground tunnels side-piercing bridge piles have emerged in recent years. In this paper, in order to investigate the law of seismic response of a short-distance side-piercing bridge pile system in a tunnel structure, a shaking table was designed and implemented, which is based on the actual engineering background of a tunnel crossing the elevated Line 3 bridge pile in Dalian, China. Based on relevant test data, the acceleration and strain responses of the site and structure were analyzed and quantitatively evaluated. The analysis results showed that the presence of a tunnel or bridge pile structure significantly reduces the frequency of the system. Regarding the law of seismic response of interaction system, it was found that the existence of the tunnel structure and bridge pile has weakened the rigidity of the whole model, and therefore, the seismic response of surrounding soil was amplified. It was observed that the bridge pile suppresses the seismic response of the tunnel; however, the tunnel will amplify the acceleration response of the bridge pile. In addition, the existence of bridge piles increases the strain response of the tunnel, and the strain at the bottom of the bridge piles increases due to the influence of the sidewall of the tunnel.