Flood-induced forces and collapse mechanism of historical multi-span masonry arch bridges: The Putang bridge case

Abstract

In order to obtain an adequate understanding of the vulnerability of historical multi-span masonry bridges during flood hazards for the better conservation, a typical multi-span stone arch bridge, Putang Bridge, is chosen to carry out the study on the collapse mechanism of the bridge under flood-induced forces based on numerical simulations. This study has a twofold objective: to simulate numerically the forces exerted by floods on the bridge, and to figure out the collapse mechanism under the obtained flood loads. The hydrodynamic pressure distribution and drag and lift forces on the bridge are predicted with CFD simulation considering eight different flooding levels. The simulation method is validated in advance with existing experiments. A bridge with higher cutwaters is modeled to assess the effects of the height of cutwaters on mitigating the flood loads. A finite element model of the bridge is developed and the obtained flood loads are applied to investigate the vulnerability of arch bridges in floods. The findings of this research could contribute to a clear comprehension of the flood-induced forces on arch bridges and the structural vulnerability, and also could provide some insights on preparing the early warning strategy and preventive measures for historical masonry arch bridges.