多摩川水系における河川横断構造物の予防保全に向けての具体的検討

抄録

In the Tama river system, river crossing structures and sediment depositted upstream of the structure decreases flow capacity. Existence of shale exposed at the river bed is one of causes of structure damages. Therefore, repairs of the weir and checking of river bed variation are main preventive maintenance works in the Tama river. In this paper, we investigate by surveying change in river crossing structure and channel bed before and after repairing. Following points were adopted as the basic concept for preventive maintenance of Tama river. They are detailed investigation of bed changes in river course and around crossing structures, countermeasures against their change, and proper engineering and administrative approach to preventive river management. Attentions are also paid on other crossing structures which need countermeasure from now on.