多摩川における許可工作物の維持管理を含めた河道管理

抄録

In order to prevent the fall of the bridge piers from local scouring, streambed protection works are conducted for almost all bridges of the upper reach of the Tama river. But the circumference of the piers of railway bridges and highway bridges had suffered a great deal of damages from every flood because erosion of shale soils exposed at the river bed advanced due to the extreme degradation of river bed. Although bridges are permitted structures, it is necessary for the safety of the facilities that river administrators should give a proper guidance to facility managers.

In this paper, the present situation of streambed protection works and bed change are investigated for the execution of proper maintenance and management of rivers. We propose an idea for river management including the maintenance of the permitted structures.