Study on the Failure Mechanism of Bridge Pier in the Active Debris Flow Regions

Abstract

Highway bridges and culverts across debris flow gully are easy to be impacted by debris flow. When debris flow break out, the bridge pier foundation is scoured and undercutted by debris flow, which could lead to scour hole in a certain degree. Based on the model that mutant river scoured roadbed along the river in mountainous areas, putting the bridge pier that was scoured by debris flow as the research object, then we analyze the mechanism that the debris flow undercuts bridge pier foundation, and study changes in the stability of bridge superstructure after the formation of the scour hole. Finally, the rationality of the failure mechanism is verified by the calculation of the relevant engineering examples.