EROSION ANALYSIS BY OVERFLOWING WATER ON LOCAL RIVER EMBANKMENT AND CONSIDERATION OF THE EFFECTS OF SOIL CONDITIONS ON EROSION

Abstract

 Soil conditions of river embankment largely differ in each place and it affects the hardness to be broken. The objective of this study is to analyze the effects of soil conditions on the erosion by overflowing water on embankment. Dry density and clay content (as a soil constant) were selected for the dominant factors, and the difference in material of each layer in the embankment section was considered. Erosion of cohesive soil was calculated by inputting soil data in river embankment along the Oppe river into the erosion equations. This study clarified that the embankment greatly erodes and collapses when the critical shear stress is less than a specific threshold. This study also showed that it is necessary to set a soil constant for each stratified material instead of using a cross-sectional averaged value of soil constant for obtaining a more accurate erosion profile, especially when the overflow duration is long.