2018 Volume 24 Pages 149-154
We attempted to understand the basic knowledge to prevent settlement and inclination of abutments which occurred in many bridges during Hokkaido heavy rain in 2016. By experiments of movable bed models, some of the important findings were obtained as follows; (1) an abutment could not be self-sustaining because of bed scouring caused from large-scale bank erosion, (2) in the vicinity of the abutment, riverbed degradation proceeded along with the 3 phases change. These phases were (a) a riverbank reached to the abutment by erosion, (b) occurrence of flow that was similar to flow around a tip of a spur dike, and (c) occurrence of flow that was similar to flow around a pier.
