Research On The Regulation Of Surface Cracks For Xiaonan Coal Mine In Tiefa Caused By Igneous Rock Fracture

Coal resource is an important energy to support the development of the economic construction and people's life in China today, increasing demands also make the mining area increased greatly. Then the following geological disasters will bring about increasingly prominent. Mining surface crack is a kind of the subsidence damage forms due to coal mining, which can not only endanger people's life and property safety owing to the buildings crack, but also bring economic losses as a result of the soil discontinuous failure. Especially when the geological conditions are relatively complex, many factors lead to more serious damage fracture.This article taking the surface cracks of Xiaonan Coal Mine in Tiefa caused by coal seam mining as the research example. First of all, in the investigation of the mining engineering and the coal mining, statistical analysis of the crack formation conditions. According to the geological conditions of mining area, system analysis the surface cracks, formation characteristics when there is special geological conditions. In other words, a hard roof is located in the mined-out area overlying. What's more, this article aiming at solving the stability problem when part of the hard roof strata are influenced by mining, establishing the mechanical model and stress analysis, founding that the span length of igneous rock in Xiaonan coal mine is greater than the maximum safe length can afford, so the disturbed effect of igneous rocks appear rupture deformation and surface caused by large scale cracking. Lastly, for the actual mining situation of Xiaonan Coal mine, numerical simulation is conducted using FLAC3D finite difference software on the roof rock deformation and failure process, and verify the correctness of the model. After analysis the simulation cloud pictures of displacement, stress and plastic state, reason to draw Xiaonan Mine Surface Cracks is the special geological conditions of the igneous rock hard roof strata in multiple mined out area above the confluence area, so the coal mining above the table rock tension degree intensifies and igneous rock fracture under suspended such comprehensive factors contributed to the formation of surface crack of Xiaonan Coal mine.