Erosion Processes of River Bank with Strata

Abstract

River bank erosion is fundamental and important subject of river course design. Objectives of the present study are to throw a light on erosion process of natural bank with strata and to make possible to estimate bank erosion rate. For this purpose, a channel was excavated on the flood plain of the Arakawa River. Erosion process was found to be composed of three stages: erosion of sand stratum at the lower part of bank, failure of upper overhanging silty soil in tension and transportation of failure soil block by the flow. Further, the estimating method by dynamical considerations was established for failure of the upper silty soil and transportation of the failure soil block.