Experimental Modeling of Quicksand with Transparent Soil through an Orifice

Abstract

Abstract Quicksand hazards severely threaten the safety of underground construction work and production in coal mines. This paper presents an experimental investigation on quicksand through an orifice. The flow velocity, flow patterns, and quicksand volume are examined using digital image processing of transparent soil. An experimental setup for modeling quicksand is designed according to simplified geological conditions. In the experiments, fused quartz is used to simulate the sand, and a mixed mineral oil that has the same refractive index as that of the fused quartz is used to simulate the pore fluid. Different conditions of quicksand are then modeled. Images of the modeling processes are captured and analyzed. The velocity of the sand flow and velocity distributions are obtained by using digital image correlation. The results show that there are two flow patterns: column and funnel. The sand moves vertically in the column, and the flow velocity field is distributed in an elliptical-like bubble shape. In the funnel pattern, the sand moves along a slope surface, faster than the sands inside, until they both reach a stagnant zone. The analysis results of the flow velocity and volume of the sand show that the quicksand process can be divided into four stages: initial, stable, unstable, and end stages. Furthermore, there are two typical modes of quicksand: uniform and non-uniform slope receding modes.