Overlying Strata Fissures Evolution And Methane Delivery Law Of High Gas Thick Coal Seam And Its Application Analysis

The overburden rock fissures evolution and pressure relief gas migration law is the core technology of "coal and gas safety mining", and it is important for coal mine gas prevention and control. This thesis took high gas thick coal seam as the object, and studied overlying strata fissures evolution by using similar simulation experiment. Then FLUENT software was used to simulate gas delivery law in mining fissure in the purpose of providing a theoretical basis for gas drainage practical applications in Wuyang coal mine.Based on analyzing the characteristics of overburden deformation, the similar simulation experiment was used to study overlying strata cracks evolution during thick coal mining. The development height of "three zones" and development law of overburden fissure have been obtained. The results show that with the workface advancing, overburden occur periodic breakage and movement, and after the middle part of goaf compacted, the fissure around goaf interconnected each other and formed O ring. The fluent software was used to simulate gas migration law in mining fissure, and the three-dimensional distribution of gas concentration in stope and the influence of tail roadway to the distribution of gas concentration have been obtained. The results show that the upper part of the return air side of goaf is gas-rich region, and it is the best place to arrange gas drainage drilling orroadway.This paper selected 7602 fully mechanized caving workface as the object to perform coal and gas mining technology practice. Engineering practice has obtained the gas concentration distribution law, also determined coal cutting reasonable speed of shearer, and proposed gas drainage in roof mining fissures and gas tail roadway method. Comprehensive treatment effect of 7602 workface showed that the layout of gas drainage system was reasonable. It can eliminate gas accidents in coal mine, also guarantee the safety and efficient production of fully mechanized caving face. It can provide some reference for safe and efficient production of similar conditions coal resources.