Mechanical Characteristics Of Coal And Rock Mass And Control Of Roadway Surrounding Rock Non-uniform Deformation

As the main energy in China,coal occupies an important position in the development of national energy strategy.In recent years,with the development of technology,mining machinery,the unprecedented development of technology and equipment,makes half coal rock ore also increases in mining depth,the big cross section of roadway are frequently used,which is associated with the deformation of roadway surrounding rock and increase,and the characteristics of long duration and wide spread,the traditional way of supporting has far cannot satisfy the requirement of safe mining.Therefore,the analysis of the non-uniform deformation characteristics of the surrounding rock of the semi-coal roadway and the study of the supporting scheme of the surrounding rock have become one of the keys to solve this kind of problems.Based on the tutor’s national Fund project"Uneven deformation mechanism and Support Structure adaptability of deep weak coal and rock roadway（51974117）",this paper takes Dongsun Coal Mine four-coal three-stage track roadway as the research background.By means of theoretical analysis,field test and monitoring,laboratory test,numerical simulation and other research methods,the uneven deformation analysis and support structure of surrounding rock of four-coal three-stage semi-coal roadway are studied,and the main achievements are as follows:（1）Through the field investigation of the four-coal three-stage semi-coal rock roadway,the deformation characteristics and factors of the roadway are summarized.The mineral composition of the roof and floor surrounding rock is analyzed by X-ray diffractometer,and the rock spying test shows that the surrounding rock deformation of the roof and two sides of the semi-coal roadway is more serious,and it is paid attention to in the support process.（2）The deformation and failure mechanism of semi-coal rock roadway is analyzed.First of all,the surrounding rock strength of the two sides of the semi-coal rock is low,and the fissures of the surrounding rock of the semi-coal rock are obviously developed,resulting in a large dilatation stress,which causes the loose coal mass of the surrounding rock of the semi-coal rock to be extruded into the roadway.Secondly,under the action of mining stress on the adjacent working face of the roadway,the anchors of the two gangs and the roof are loosened,which increases the scope of the loose circle and reduces the anchoring effect of the anchors.Finally,because the full length of the bolt is unreasonable,a relatively stable rock mass cannot be selected as the anchoring point.Therefore,if the anchor body loses its force,it will cause the bolt to move with the surrounding rock,resulting in the complete failure of the anchor body of the surrounding rock.（3）It reveals the non-uniform deformation characteristics of semi-coal rock.Through the laboratory study of semi-coal rock specimens,it is concluded that under the condition of increasing the dip Angle,the coal rock mass with different dip angles in rock mechanics tests is broken faster than the rock mass,and the deformation before the peak failure is heterogeneous,which is more fully reflected in the circumferential strain.Under cyclic loading and unloading,the dissipation energy of coal mass is faster than that of rock mass with the increase of inclination Angle.Therefore,the deformation of two sides of coal in semi-coal roadway becomes the key point of roadway support and monitoring.（4）FLAC^3D numerical simulation software was used to simulate and analyze the non-support and original support of the roadway.Six different support schemes were proposed in combination with the uneven deformation characteristics of the roadway and the actual situation.A numerical simulation model was established to compare and analyze the displacement deformation,stress distribution and plastic zone characteristics.It was concluded that Scheme 8 was the optimal scheme.（5）In the test section of the roadway,the displacement and deformation data collection of scheme 8 is compared with the numerical simulation by monitoring means,which proves that the scheme is feasible.The scheme can effectively control the deformation of the side walls and the roof and floor,the stress distribution of the surrounding rock is controlled,the bearing capacity of the supporting structure is improved,and the stability of the surrounding rock of the roadway is guaranteed.In this paper,the uneven deformation characteristics and supporting structure technology of semi-coal rock roadway in Dongsun Coal Mine are studied,and the comprehensive support scheme of‘anchor,spray,net,cable and beam’is proposed,and good deformation control is achieved,which has certain reference significance for the deformation control of surrounding rock of semi-coal rock roadway.