Mechanics-Seepage Experimental and Simulation Study of Gas-Bearing Coal under Different Load Paths

Abstract

Mechanics-seepage synchronous tests on gas-bearing coal under three different stress paths were designed and implemented to evaluate how load path affected the mechanical strength and permeability of deep mining-disturbed coal. The cracks-count evolution of coal specimens during instability was observed through DEM numerical simulation. The results showed significant stress-strain and strength variations under different paths. At the time of failure, the specimen deformation and peak strength were Test 1 > Test 2 > Test 3, while the permeability was Test 3 > Test 2 > Test 1, with specimen permeability in Test 3 rising prominently. From numerical simulation, the cracks count was Test 2 > Test 3 > Test 1, with tensile cracks taking the largest proportion in Test 2 and shear cracks taking the largest proportion in Test 3. Our findings shed some light on the research and disaster prevention regarding coal and gas outburst.

Special Issue “Process Safety in Coal Mining”

“…Haitao Sun and coworkers [19] further clarified the occurrence and developmental mechanism of coal-rock gas composite dynamic disasters in an engineering-scale mining environment and provided guidelines for the prevention and control of coal-rock gas dynamic disasters in deep mines. Haibo Sun and coworkers [20] observed the law behind the evolution in the number of cracks in the process of coal specimen instability via DEM-based numerical simulation.…”