Study on failure characteristics and soil pressure change of simply supported beam bridge across fault under creep fault

Fault displacement is a major hazard threatening the safety of bridges crossing faults. Compared to sudden stick-slip movements, creep fault displacements release stress at a low speed and continuous manner, potentially leading to progressive damage of bridge structures due to their cumulative effects. To investigate the effects of different types of fault displacements on bridges crossing faults, this study conducted a series of tests on a 1:50 scale model of a simply supported beam bridge using a self-developed fault simulation test device. The displacement processes of strike-slip, normal, and reverse faults were simulated, and the failure characteristics and mechanisms of the bridge structure under different fault actions were comparatively analyzed. The results show that: (1) Different types of faults exhibit distinct movement characteristics, leading to varied destructive effects on bridges crossing faults; (2) The relative displacement of bridge piers and soil deformation caused by fault displacement are the main reasons for bridge structure failure; (3) Different types of faults lead to significantly distinct soil pressure distributions, reflecting the complex effects of fault movements on the surrounding soil; (4) The inherent characteristics of the bridge structure, such as bearing constraint conditions and girder connection states, have important influences on its ability to resist fault displacement. The research results provide theoretical references for the seismic and fault-resistant design of bridges crossing faults.