Research On Roof Deformation Mechanism And Control Technology Of Roadway Staying Along Goaf

In order to alleviate the shortage of coal resources demand and reduce the waste of protective coal pillars in working face,the technology of gob side entry retaining without protective coal pillars in working face is adopted.Through the recovery of protective coal pillars,the waste of coal resources is reduced,the problem of corner tile accumulation is eliminated,the length of roadway excavation is reduced,and the labor intensity of workers is reduced,In the same output of coal resources,reduce the cost of industrial production,realize the efficient and safe mining of coal resources.Roof cutting and pressure relief gob side entry retaining technology cuts off the connection between roof and goaf through roof cutting technology,and there are many factors affecting the structural movement Therefore,the control of the roof of roadway retaining needs to further study the internal mechanism of the roof of roadway retaining,and put forward the corresponding support scheme.In this paper,the deformation mechanism of the roof of the retaining roadway and the control of surrounding rock are discussed.Based on the practical engineering background of the transportation roadway in the Ⅱ 632 working face of Hengyuan coal mine,the paper analyzes the breaking structure of the roof along the goaf by the top unloading and builds the mechanical model,The paper analyzes the characteristics of overburden movement of roof covering along the goaf by using two sides four-way loading experimental platform and numerical simulation research method,analyzes the relationship between the retaining resistance and key parameters,and the deformation characteristics of surrounding rock in different stages of the roadway during the process of advancing the working face of mining.On this basis,the strengthening support scheme is proposed to control the deformation of the surrounding rock in the roadway,The results are as follows:Through the key layer theory and hinge theory,the mechanical structure model is constructed,and the mathematical analytical formula of retaining roadway support resistance is obtained.The influence of different factors on the supporting resistance of the roof of the retaining roadway is analyzed.With the increase of the cutting angle and the height of the cut top,the supporting resistance required for the roof of the retaining roadway will increase accordingly.FLAC3D numerical simulation is used to analyze the actual engineering geological conditions.The reasonable cutting angle of the transportation roadway in the Ⅱ 632 working face of Hengyuan coal mine is analyzed.The reasonable cutting angle is 15°,When the height of the cutting top is 8m,the cutting technology can cut off the connection between the overlying strata,and cut off the way of stress transmission of the overlying strata.The actual situation of the roadway retaining in the transport roadway of the Ⅱ 632 working face of Hengyuan coal mine is simulated by two sides four-way loading experimental platform.The reasonable cutting top parameters are obtained by numerical simulation to simulate the stability of the surrounding rock under the influence of primary mining,The deformation of surrounding rock and the collapse of rock above the goaf of the working face are recorded by using the digital recording technology and stress monitoring equipment By the constant load of surrounding rock,the roof of the retaining roadway will bend and sink.The bottom plate will appear with the stress relief of the goaf during the mining process.The technology of cutting top and pressure relief can cut off the connection between the roof of the retaining roadway and the overlying strata in the goaf.The roof of the goaf directly slides down along the cutting top line,and the gangue falling is full of the goaf.Based on the similar simulation experiment,the influence range of the working face on the roadway retention during the process of advancing in sections is analyzed.The deformation and stress distribution of surrounding rock in the retaining roadway in different periods are obtained by numerical simulation.Through theoretical analysis,numerical simulation and similar simulation structure,the paper proposes the way of strengthening support by anchor net cable,and applies it to the transportation roadway of working face Ⅱ 632 of Hengyuan coal mine.Through the monitoring of surrounding rock deformation,the deformation of surrounding rock in the roadway is small,and the retaining roadway can be used safely for the next mining face.Figure[69]Table[3]Reference[91]...