Safety Verification of Sabo Dams Against Large Scale Debris Flow

Nobutaka ISHIKAWA, Joji SHIMA, Ryo MATSUZAWA and Takahisa MIZUYAMA

Recently concrete and steel open-type Sabo dams (hereafter, steel open dam) have been damaged by large scale debris flow load (hereafter, load level 2). This was caused due to large rocks carried in the debris flow resulted from torrential rainfall of abnormal weather. This paper presents safety verification methods of concrete and steel open dams against load level 2. First, the estimation methods of load level 2 are explained. The fluid force and rock impact of load level 2 are assumed by performing the extreme stability analysis and by the field survey of the past debris flow disaster. Second, the safety verification methods for concrete and steel open dams are proposed against the load level 2 from the viewpoint of performance-based design. Finally, numerical examples of concrete and steel open dams are illustrated against load level 2 by performing the FEM impact analysis using the software of ANSYS AUTODYN.

2018/1 145-152