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

**Haibo Sun 1,2,\*, Baoyong Zhang 1, Zhijun Song 1, Bin Shen <sup>1</sup> and Hongyu Song <sup>1</sup>**

<sup>2</sup> Heilongjiang Longmei Jixi Mining Co., Ltd., Jixi 158199, China

**\*** Correspondence: shbbs\_hlj@163.com

**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 stressstrain 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.

**Keywords:** triaxial; permeability; strain; DEM; crack
