EVALUATION OF EXERTING FORCE AS DESIGNING DRY-LAID MASONRY TYPE OF REVETMENTS IN RIVER BENDS

In order to prepare the guide for designing rich-in-nature type of revetments, we are making some researches into hydraulic characteristics and bank erosion in river bends. In this paper, first, we examine the distribution of flow velocity and the stability of dry-laid masonry type of revetments in river bends by experiments. Then, 2D numerical simulations are carried out to investigate the velocity characteristics under several kinds of conditions. It is shown that the index νtoe/νavg (νtoe: the maximum depth-averaged velocity over the toe of the outer bank, νavg: the average velocity in the approach channel) is useful for evaluation of exerting force on revetments, and that some kinds of parameters such as r (the radius of curvature)/B (the width of river), dimensionless shear stress in the approach channel τ·0, Froude number Fr, etc. have an influence on the value of index νtoe/νavg.