1. Southern Coal Mine Gas and Roof Disaster Prevention and Control and Safety Production Key Laboratory, Hunan Province Key Laboratory of Coal Mine Safety Technology, Hunan University of Science and Technology, Xiangtan, Hunan 411201, China
2. Department of Civil Engineering and Engineering Mechanics, University of Arizona, Tucson, USA
3. School of Civil Engineering, Hefei University of Technology, Hefei, Anhui 230009, China
4. School of Resources and Safety Engineering, Central South University, Changsha, Hunan 410083, China