土石流の構成則に関する研究

Abstract

Critical reviews on the studies for grain flows or debris flows are made from aviewpoint of continuum mechanics, which are expected to be an indicator for futureresearches on debris flows.The dissipation function for the flow of solid particle and fluid mixture isdeduced by formulating the energy consumptions due to the three mechanisms; theparticle to particle displacements, the inelastic collisions of the particle to particleand the turbulence generation within the pore fluid. The shear stress, which is calleddissipative stress, is directly obtained from the dissipation function. The isotropicpressure, which depends on the pressure of pore water, static concentration of solidparticle and repulsive dynamic stress, is formulated. Formulas of velocity andparticle concentration distributions are obtained from applying these stress relationsto the conservation equation of linear momentum. The theoretical predictions arecompared with flume tests performed by employing mixtures of sand particles andwater as well as of glass beads and water.