EXPERIMENTAL STUDY OF EROSION RATE AND CRITICAL TRACTIVE FORCE ON SOFT ROCKS

Abstract

The area of exposed soft rocks has been increased due to river bed degradation in the vicinity of Asahikawa City of the Ishikari River. According to the soft rocks have a specific feature in which the local erosion can be caused easily due to high flow velocity, there is a possibility of decreasing the stability of the bridge pier and the shore protection. However, the morphology of sand riverbed and the morphology of soft rock riverbed are different phenomenon, the general bed load transport formula cannot reproduce the bed deformation sufficiently in the area of exposed rocks. In this paper, the relational expression of the erosion rate of the soft rock and the critical tractive force on the soft rock are generated based on the experimental observation.