1. School of Civil Engineering, Chongqing Jiaotong University, Chongqing 400074, China
2. National and Local Joint Engineering Research Center of Shale Gas Exploration and Development, Chongqing Institute of Geology and Mineral Resources, Chongqing 401120, China
3. State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, China
4. Faculty of Engineering Technology, Universiti Tun Hussein Onn Malaysia, Parit Raja 86400, Johor, Malaysia