1. School of Civil Engineering, Hefei University of Technology, Hefei, China;
2. School of Resources and Safety Engineering, Central South University, Changsha, China;
3. Work Safety Key Lab on Prevention and Control of Gas and Roof Disasters for Southern Coal Mines, Hunan Provincial Key Laboratory of Safe Mining Techniques of Coal Mines, Hunan University of Science and Technology, Xiangtan, China;
4. State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing, China