1. School of Resources and Safety Engineering, Central South Univ., Changsha 410083, CN, e-mail: xbli@mail.csu.edu.cn
2. School of Resources and Safety Engineering, Central South Univ., Changsha 410083, CN, e-mail: shangxueyi@csu.edu.cn
3. State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing Univ., Chongqing 400044, CN
4. College of Resources and Environmental Science, Chongqing Univ., Chongqing 400030, CN (Corresponding author), e-mail: pengkang@cqu.edu.cn