1. Shandong Geological Environment Ecological Restoration Engineering Research Center, Shandong Provincial Research Institute of Coal Geology Planning and Exploration, Jinan, P. R. China
2. State Key Laboratory for Geomechanics and Deep Underground Engineering, China University of Mining and Technology, Xuzhou, P. R. China
3. Research Center of Deep Ocean Science and Underwater Engineering, China University of Mining and Technology, Xuzhou, P. R. China
4. School of Resources and Geosciences, China University of Mining and Technology, Xuzhou, P. R. China