Study on the Law of Overlaying Key Strata Motion in Short Wall Mining

摘要

Short wall mining is one of the effective ways to control ground subsidence and solve the difficult problem in the coal mining under buildings, railways and water bodies. And it is of great significance to develop the whole sets of techniques of the short wall mechanized mining and ground pressure control, which adapt to the geological conditions in China. There is one or several thick hard rock strata, which play an important role in the motion of whole overlaying strata, and this kind of strata are called key strata. In this paper, based on the modern mechanics theory, the overlaying key strata and the coal safety pillars are studied by FLAC4.0 software, which is used to simulate the deformation of surrounding rock in coalface of short wall mining. The deformation of roof key strata and the coal safety pillar retained are analyzed and the reasonable ratio of mined-out strip to pillar is obtained under different mining conditions, which provides available references for the parameters choice of short wall mining and engineering application.