Study On Stability Of Surrounding Rock Of High Stress And Complex Surrounding Rock Conditions Of Roadway Driving Along Next Goaf In Dongtan Coal Mine

Coal is the main energy in China.With the continuous coal mining,in order to improve the recovery rate of fully mechanized caving coal mining,domestic scholars put forward the method of using narrow coal pillar to excavate the roadway along the goaf.For deep mining roadway along gob,the surrounding rock conditions of roadway are complex and the stress is concentrated.The research is of great significance to reduce the loss of coal mining,reduce the cost of roadway support and maintenance,improve the economic bene fit and ensure the safety of production.Therefore,through theoretical analysis,numerical simulation,field test and other methods,this paper studies the deformation law and support optimization of roadway along the goaf under the conditions of high stress,high coal seam,roof rich in soft interlayer,small coal pillar and other complex surrounding rocks.The main research contents and results are as follows.(1)Through fracture damage theory,the elastoplastic theory is adopted to establish the coal wall of roadway surround rock crack plate structure mechanics model,analyzed the coal to help increase with height and mutation type shear slip deformation instability characteristics,analyzed the mining depth,high lane width and lane,factors such as intensity of surrounding rock of coal for the influence of shear slip deformation,confirmed when the surrounding rock of roadway supporting pressure exceeds the minimum critical buckling load when the result will be a piece of help.It is concluded that corresponding measures must be taken to reduce the shear slip failure of high coal seam.Through the research on the weak inter layer in the relative position of roof,it is divided into the anchorage zone,the edge of the anchorage zone and the outside of the anchorage zone,and the conclusion of the influence of different layers on the stability of roadway roof is obtained.FLAC was used to analyze the influence of small coal pillars with different width-to-height ratio on the supporting effect,and the optimal small coal pillars with small width-to-height ratio were determined.(2)In Dongtan coal mine complex coal roadway driving along goaf roadway surrounding rock conditions,determine the reasonable ratio of high to width of coal pillar and support forms and support parameters,put forward the "Three high and Three strengthening" control technology principle,formed mainly include high strength and lengthen roof bolt and anchor rope combined support with suspension single hydraulic prop to strengthen,large aperture high pretightening force of anchor beam(truss)control high coal for shear slip deformation,small coal pillar all-thread bolt support and other means to control surrounding rock deformation of roadway.(3)According to the principle of control technology,the concrete support scheme and parameter design for 1306roadway excavation along gob are developed and the roadway deformation monitoring,monitoring data analysis and processing as well as the roadway forming effect are statistically analyzed.The results show that the application of this technology can effectively control the deformation of roadway along the goaf under the condition of high stress and complex surrounding rock in dongtan coal mine,and effectively maintain the stability of surrounding rock.