1. School of Transportation Engineering, Jiangsu Vocational Institute of Architectural Technology, Xuzhou, Jiangsu 221116, China
2. Xuzhou Coal Mining Group Corporation, Ltd, Xuzhou, Jiangsu 221018, China
3. State Key Laboratory of Coal Resources and Mine Safety, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China
4. Science & Technology Innovation Center, Coal Mining and Designing Department, Tiandi Science & Technology Co, Ltd, Beijing 100013, China