1. College of Mining Engineering, Taiyuan University of Technology, Taiyuan 030024, China
2. Key Laboratory of Shanxi Province for Mine Rock Strata Control and Disaster Prevention, Taiyuan University of Technology, Taiyuan 030024, China
3. Key Laboratory of Highway Construction and Maintenance Technology in Loess Region of Ministry of Transport, Shanxi Transportation Technology Research & Development Co., Ltd., Taiyuan 030032, China