Research On Analysis Of The Narrow Coal Pillar Stability And Its Surrounding Rock Controlling In Three-soft-coal Seam Drifting Along Goaf

With the further extension of the depth of mine development, the coal pillar width is more and more important to maintain the stability of the surrounding rock. Selecting a smaller width of coal pillar can reduce the loss of coal resources.And narrow coal pillar is an important part of surrounding rock structure of the surrounding rock, and its stability is the key to the implementation of the technology.This paper in Renlou Coal Mine 7259 working face as the research background, in the "soft roof, soft coal and soft floor is three soft characteristic conditions, using theoretical analysis, numerical simulation and engineering analogy method, the stability of narrow coal pillar, the reasonable width of coal pillar design and problems along the roadway surrounding rock control are discussed study. Firstly from the mechanism of the stability of coal pillar as the starting point, by building the mechanical model of the roadway driving along, research along the empty tunnel overburden broken fault structure characteristics, focusing on to during excavation and mining impact phase arc triangle structure of the key rock block B of the stress analysis and research of the coal pillar deformation damage mechanics theory support,Then the distribution and digging period, recovery period comparison of different coal pillar width should stress distribution and displacement variation, analysis the role of supporting roadway of different coal pillar width effect then, used FLAC3D numerical simulation software, a numerical model is established and the dig Xiang frontier empty coal edge stress, step judging the stability of narrow coal pillar, and on the basis of the coal pillar failure mechanism of the coal pillar, the design principle and law of deformation and failure. Through the coal pillar strength empirical formula, the above research means to determine the final edge of the narrow coal pillar of a reasonable size of 5m. Combined with the actual conditions in the field, adopted "a anchor belt net cable secondary high subsidiary strong reinforcement support combined supporting with supporting scheme, can effectively control the deformation of surrounding rock and obtain better effect of support, to further improve the three soft coal seam conditions along the goaf mining roadway surrounding rock control technology, similar conditions along goaf digging pillar design and the roadway to provide certain theoretical basis and reference value of along goaf digging roadway design scientific and mine production safety is of great significance.