1. Key Laboratory of Mining Disaster Prevention and Control, Shandong University of Science and Technology, Qingdao 266590, China
2. National Experimental Teaching Demonstration Center of Mining Engineering, Shandong University of Science and Technology, Qingdao 266590, China
3. Department of Civil and Environmental Engineering, Stanford University, Stanford, California 94305, United States
4. College of Pipeline and Civil Engineering, China University of Petroleum (East China), Qingdao 266580, China