Law governing strata and ground movement due to sub-critical extraction
(1.China University of Mining and Technology Beijing Campus, Beijing 100083, China2.Beijing, University of Science and Technology Beijing 1000833.Central Coal Research Institute, Tangshan Branch, Tangshan 063012, China)
Abstract: The strata movement induced by sub-critical extraction is a problem not receiving due attention because of its relatively small magnitude of deformation. However, with the increase of mining depth, sub-critical extraction has become a general phenomenon. This calls for an in-depth investigation into the characteristics of ground movements observed under different extents of sub-critical extraction, so as to determine the appropriate mining technique for use. Following a discussion of the factors influencing the extent of super-critical extraction, the super-critical extraction extent evaluation criteria was presented, the characteristics and laws of the strata and ground movements caused by such an extraction condition were systematically analyzed, and the mechanism of surface subsidence induced by sub-critical extraction was revealed. The result of study may serve as a basis for the development of the strata and ground movement prediction model and the mining techniques appropriate for use at depth beneath surface structures and buildings.
Key words: sub-critical extraction； strata and ground movement； extent of mining evaluation criteria.；