Riverine flow and floating wooden debris interaction with an arch bridge: flume experiments

Masonry arch bridges (MABs) are vulnerable to flood effects. Whilst previous studies have focused on scour around bridge piers, very little investigation has been conducted on the flood effects on the superstructure of MABs. This paper is the first experimental study to provide an understanding of this complex phenomenon. The generation of detailed pressure–time and force–time histories on MABs with different submergence ratios and debris orientations enables useful insights into the physics involved while providing critical data for the validation of future numerical models. The results without floating debris indicate that hydrodynamic pressures and forces were captured with high precision, while it decreased with a coefficient of variation of 34.54% close to the free surface. In the cases with debris, multiple impact pressures and forces were obtained. Furthermore, a 0° orientation is more prone to debris accumulation and associated afflux at the bridge superstructure compared to a 90° situation.