1. Key Laboratory of Coalbed Methane Resource & Reservoir Formation Process, Ministry of Education, China University of Mining & Technology, Xuzhou 221008, China
2. Department of Civil Engineering, Lishui University, Lishui 323000, China
3. School of Mines, Inner Mongolia University of Technology, Hohhot 010051, China
4. School of Civil Engineering, Chongqing Three Gorges University, Chongqing 404100, China
5. Department of Earth and Environmental Sciences, The University of Texas at Arlington, Arlington, Texas 76019, United States
6. College of Mining Engineering, Heilongjiang University of Science and Technology, Harbin 150090, China