In order to prevent the mine-earthquake caused by suddenly collapse of large scale goafs, the isolation roof caving control and monitoring technology is put forward innovatively. Through statistical analysis and numerical simulation analysis, 20,000 square meter goaf that selected as one isolation roof caving unit is reasonable and practicable. The thesis gives concrete exposition for roof caving control and monitoring technology in the aspects such as roof caving parameters design, safety calculation, construction technology, surface subsidence monitoring and internal strata displacement monitoring, etc. In addition, case analysis was developed. The results show that the isolation roof caving control technology can effectively avoid or decrease the mine-earthquake, while the technology can partly release the concentration stress of pillars. Combined surface subsidence monitoring with internal strata displacement monitoring, the displacement change of every strata above the goafs can be monitored, so the control effect can be significance tested.
In the past time from earlier 1980's to 2000's, almost all the coalmines in Midwest China took the method of part mining, typical room and pillar method. According to incomplete statistics, by the end of 2012, only the area of room and pillar method goafs in Ordos and Yulin City had reached 650 km2. With the development of technical renovation and production of new coal corporations, room and pillar method goafs have become the important factorswhich cause serious geological hazard and environmental problems. The room and pillar method goafs have impacted the safety and sustainable development of regions and enterprises in China. The coalmine goafs typical room and pillar method goafs prevention and control has become the significant challenge faced by the government and enterprises.
In the terms of room and pillar method goafs prevention and control, many experts and scholars conducted a series of researches (Chunqing & Xiang 2004, Bigen&Chunlai 2007). Combining many years' experience of Chinese Coal Research Institute (CCRI 2010,Wen 2011, 2013,Wen &Yi 2011, Rutie &Wen 2012), they proposed the control methods such as open stripe and reclamation, full grouting, the residual pillar filling for recovery, etc. More than 480 local coalmines in Ordos City and Yulin City were investigated, reconnaissance and prospected. About 40 percent of goafs are distributed under loess plateau and hilly area, while the buried depth is more than 80 m, with no or unimportant buildings and structures on surface, and the range of goafs distribution is unrevealed. Through analyses, the three methods mentioned above are not suitable to control these goafs. In addition, the frequency mine earthquake accidents induced by sudden collapse of large-scale of coalmine goafs put forward higher requests. In order to prevent and control the mine earthquake induced by suddenly collapse of large scale coalmine goafs, based on the previous researches, aiming at the features of terrain and geological characteristics of room and pillar method goafs, the surface isolation roof caving control and monitoring technology is put forward innovatively.
