Energy School Xi'an University of Science and Technology Xi'an 710054 China;
Key Laboratory of Western Mines and Hazards Prevention Ministry of Education of China Xi'an 710054 China;
Energy School Xi'an University of Science and Technology Xi'an 710054 China;
Energy School Xi'an University of Science and Technology Xi'an 710054 China;
Energy School Xi'an University of Science and Technology Xi'an 710054 China;
School of Highway Chang'an University Xi'an 710064 China;
Beijing General Research Institute of Mining&Metallurgy Beijing 100160 China;
Department of Civil Engineering Inha University Incheon 402-751 South Korea;