1. School of Civil and Resources Engineering, University of Science and Technology Beijing, Xueyuan Road 30, Beijing 100083, China
2. State Key Laboratory of High-Efficient Mining and Safety of Metal Mines of Ministry of Education, University of Science and Technology Beijing, Xueyuan Road 30, Beijing 100083, China
3. Norman B. Keevil Institute of Mining Engineering, University of British Columbia, Vancouver V6T 1Z4, Canada
4. Barun Mining Branch, Inner Mongolia Baotou Steel Union Co., Ltd., by Share Ltd, Damao Banner, Baotou 014080, China