THE EFFECT OF SEDIMENT CAPTURING OF LARGE STONES ON CLAY BED EROSION AND THE DEFORMATION PROCESS

Abstract

 The Tama river and the Kinu river have degraded by shale bed exposure which the shale bed is con-solidated clay bed. The shale bed exposure has caused serious degradation of river bed during floods. It is necessary to recovery of river bed by covering shale bed with sand. As a first step, it is investigated that the effect of capturing sediment from upsteam by imitating large stones in a row on the clay bed and the deformation of clay bed by the sediment. First, sand layer is formed on clay layer by the effect of large stones placed on the clay bed. Second, the structure of the bed surface and erosion resistance are different by the process of channel erosion with clay bed. Finally, the characteristic displacement of the stones is caused by the action of water flow.