Research On The Key Technology Of Top Cutting Pressure-relieve And High Water Filling And Gob-side Entry Retaining In High Gas Mine

In the development process of coal mining,retaining section coal pillars is the most common mining method.However,retaining coal pillars often causes problems such as waste of coal resources,stress concentration,and goaf fires.In order to improve these problems,scholars at home and abroad have experienced The theoretical research and on-site practice put forward the mining technology along the goaf.However,problems such as large deformation of the surrounding rock of the roadway and excessive gas hazard gas in the retained roadway still restrict the development of this technology.Therefore,this paper takes the geological conditions of the hard roof of the high gas and thin coal seams in Xinmin Coal Mine as the research background,and uses the method of combining theoretical analysis and calculation,numerical simulation,laboratory test and engineering field test to carry out optimization of the surrounding rock stress and effective sealing of the stope.Research on the key technology of cutting roof and pressure relief combined with high-water filling in the goaf and retaining roadway along the goaf.Theoretical analysis of the supporting and surrounding rock structure characteristics of the roadway remaining along the goaf is constructed,the mechanical model of the surrounding rock of the roadway remaining along the goaf is constructed,and the corresponding formula for calculating the roadside supporting resistance is derived.A numerical calculation model was established.According to the theory of roof rock strata structure and rock swelling characteristics,the cutting roof height was studied and calculated;the pre-crack cutting roof angle was determined according to the masonry beam theory and the SR stability principle of the surrounding rock structure;The pre-splitting blasting test confirmed the reasonable pre-splitting blasting parameters and verified the rationality of the top-cutting parameters.The Fluent numerical simulation software was used to simulate and study the air leakage characteristics in the Y-shaped ventilation mode of the cut-top and pressure-relief roadway.The total amount of air leakage in the goaf area of ??the entire roadway section is relatively large,which easily causes the gas concentration on the side of the goaf area to exceed the limit.Use high-water filling technology to seal the goaf along the goaf.Laboratory experiments study the properties of high-water materials,and obtained high-water materials with high-water,rapid-setting and early-strength characteristics,can maintain high residual strength and have obvious plastic characteristics after failure.Carrying out engineering field practice,through mine pressure monitoring,it is shown that after using the key technology of cutting roof pressure relief combined with high water filling to stay along the gob,the roadway deformation is small,the surrounding rock stress is reduced,the roof separation is small,and the roadside support has been achieved Expected results,and the concentration of gas in the retained roadway meets the safety mining standards,which improves the safety of mines,ensures safe and efficient mining in underground coal mines,and provides valuable experience for the further development of pillarless mining in similar mines in my country.This paper has 47 pictures,1 tables,and 73 references.