Experimental study for debris flow capture function of steel slit dam focused on solid and plane structures

Kazuki MATSUMURA and Asuka UOSAWA

A steel slit dam is one of Sabo dams with large opening formed by the combination of steel pipe, and its purpose is to capture debris flow and drift woods. There are three major advantages of it over concrete close dam: to catch drift woods, to keep designed entrapment volume, and to conserve mountain stream environment. So far, many steel slit dams have caught debris flow and drift woods, and those have been very effective to prevent disasters and minimize the damages. Comparing solid types with plane types, construction cost of solid types are more expensive than plane types because plane types need less steel. However, the plane types lack a sufficient redundancy. That means when a structural member was damaged, the potential to collapse whole structure would become higher. However the functional differences between plane types and solid types have been discussed a few. Therefore, the hydraulic experiments using two kinds of steel slit dam models were done. The results in all experiment cases show that the solid structure type has higher function than the plane structure type for the capture of debris flow.