Research On Narrow Coal Pillar Support Technology Along Goaf In Shaqu No.1 Mine

With the massive exploitation of coal resources,coal resources in some areas are gradually depleted,it is imperative to increase the recovery rate of coal resources,the mining efficiency of coal resources can be improved effectively by using narrow coal pillar tunneling technology.This paper takes the 4305 working face of Shaqu No.1Mine as the engineering background,through field research,laboratory experiments,theoretical analysis,and numerical simulation research methods,research and analysis of the physical and mechanical properties of coal rock,the overlying rock structure and stress field distribution law of the roadway along the goaf,the width of the narrow coal pillars along the goaf roadway,and the surrounding rock control plan of the roadway along the goaf,propose a narrow coal pillar roadway support technology along the goaf,and its feasibility was verified by numerical simulation,similar material simulation and industrial test.The research results of this paper are as follows:(1)Through the triaxial compression test on the coal rock samples collected from the site,the physical and mechanical parameters of coal and rock are measured,which provides data basis for theoretical calculation and numerical simulation.(2)The structure characteristics of the overlying rock along the goaf roadway are analyzed,the stability and motion state of arc triangular block B structure have important influence on the stability of goaf roadway,the basic parameters of arc triangle block B are obtained by calculation.(3)The distribution law of supporting pressure in the narrow coal pillar area is analyzed,the calculation model of working face lateral abutment pressure limit equilibrium is established,derive the calculation formula of the peak position of the support pressure and the influence range,and calculate the supporting pressure distribution characteristics of 4305 working face.(4)Analyzed the deformation process of coal pillars,the formula for calculating the width of plastic zone of coal pillar is deduced theoretically,combined with the stability conditions of coal pillar,the width of coal pillar should be at least 7.8m.The evolution law of stress field,displacement field and failure field along goaf roadway under different widths of coal pillars is numerically simulated,the width of coal pillar is8 m by comprehensive analysis.(5)By analyzing the main controlling factors and key parts of the surrounding rock deformation and failure that the roadway along the goaf may face,proposed asymmetric comprehensive support technology for surrounding rock of roadway driving along goaf,in addition,the supporting parameters of roadway surrounding rock,the reinforcement by zones and stages,and the reinforcement of surrounding rock in advance area during mining are designed.(6)Numerical simulation and similar simulation methods are used to simulate the deformation and evolution of the surrounding rock along the goaf roadway during the service period,according to the distribution law of the displacement field and stress field of the roadway,the failure mode of the roadway and the distribution characteristics of the advance support stress of the working face are obtained,the proposed support technology is feasible,and the simulation results of the two methods are not much different.(7)Through the analysis of monitoring data of ground pressure in the service period of roadway along goaf,various monitoring results show that the stability of the roadway is good,the feasibility of the proposed support technology is verified.