Journal of Natural Disaster Science

A MECHANISM OF THE DETERIORATION OF DECOMPOSED　GRANITE SOIL DUE TO SUBMERGENCE

Norihiko MIURA
Assistant Professor, Department of Civil Engineering, Yamaguchi University, Ube

(Received 15 November, 1979 and in revised form 25 December, 1979)

Abstract

Slopes of decomposed granite soil are susceptible to serious deterioration when they are inundated by heavy rain. One cause of the deterioration of soil due to inundation may be that the shear strength of decomposed granite soil is markedly decreased by submergence. However, the mechanism which produces a decrease in the shear strength of soil due to submergence has not yet been made clear. This paper shows that the decrease in shear strength of soil due to submergence is due mainly to the particle-crushing effect, which is stimulated by the action of water.

Key words

decomposed granite soil, particle-crushing, shear strength, water