1. School of Resources and Civil Engineering, Northeastern University, Shenyang, Liaoning 110819, China
2. School of Civil Engineering, Inner Mongolia University of Science and Technology, Baotou, Mongolia 014010, China
3. Dalian University of Technology, Dalian, Liaoning 116024, China
4. Institute of Mining Research, Inner Mongolia University of Science and Technology, Baotou, Mongolia 014010, China