Flow regimes in inclined open-channel flows of granular materials

Abstract

The process of a dry granular flow impacting a rigid retaining wall was systematically studied using three types of granular materials with different physical parameters. The experimental results show that the particle characteristics in terms of dynamic internal friction angle and particle diameter directly influence the flow velocity, flow thickness, critical time, and volume of the stagnant zone, and indirectly influence the proportion of the force components in the total normal force. The dissipated energy in a dry granular flow is linearly related to the product of the surface area, coefficient of internal friction, and sine of the slope angle. Impact tests of various granular materials indicate that the total normal force exerted on a retaining wall consists of a drag force (Fd), gravitational and frictional force (Fgf), and passive earth force (Fp). The existing empirical equations are suitable for the calculation of Fd for flows with Froude numbers between 6.0 and 12.4.