1. Zhaogu No.2 Mine, Henan Energy Coking Coal Company, Jiaozuo, 454000 Henan, China
2. Henan Key Laboratory of Underground Engineering and Disaster Prevention, Henan Polytechnic University, Jiaozuo 454000, China
3. School of Physics & Electronic Information Engineering, Henan Polytechnic University, Jiaozuo 454000, China
4. Collaborative Innovation Center of Coal Work Safety and Clean High Efficiency Utilization, Jiaozuo, 454000 Henan, China
5. Structural and Fire Safety Engineering, The University of Edinburgh, UK