Optimization Study Of Support For Rectangular Coal Roadway Under Horizontal Stress Conditions

San Dong coal mine the main coal mining layer 3 depth of about 800m,the coal seam belongs to the thick coal seam,the horizontal stress is big.Fractures and bedding developed in coal seam,local coal gangue,coal soft,low strength,poor integrity.As the mining needs of the mining tunnel is designed to 5×3.8m large cross-section rectangular coal lane,the impact of many factors,support difficult.The west of the mine,the bottom of layer 3 coal thickness gradually thinning.Its upper part is mainly sandstone.Hard sandstone makes the pneumatic drilling rig drilling slow,take up more personnel,low efficiency.The comprehensive level of mechanization excavating the stagnation in the 230?240 meters per month,Severely restricted the normal production of mine.In this paper,the above problems are studied in this paper,which are studied by theoretical analysis,numerical simulation and field monitoring.(1)By studying the deformation mechanism of roadway under horizontal stress and the failure mode of support system under horizontal stress,it is found that the anchor pole and rope are prone to shear failure under horizontal stress,so it is required that the support body has good shear capacity,And roadway support to use the "first control the top,the second control coalto help" support strategy.(2)through the simulation of FLAC 3D software,the influence of horizontal bedding on the stress distribution of the rectangular coal roadway is studied,and the influence of the horizontal stress field and the gangue on the stability of the surrounding rock is discussed.It is found that the relative slip occurs when the horizontal bedding is subjected to shear failure,which results in the horizontal stress acting on the coal wall.The thickness and hardness of the gangue will have an impact on the stability of the roadway.(3)through the study of the theory of large spacing support,the support parameters are optimized to realize the large distance support in the horizontal stress field.When the roof is hard to anchor construction,can by increasing the length of the bolt,increasing preload,the use of high strength to achieve large distance between the rows of roadway support.FLAC 3D software is used to simulate the different support ways of roadway to select the best scheme.According to the monitoring data of mine pressure,the simulation results are verified,and the results of numerical simulation have certain reference significance.(4)according to the monitoring data of mine pressure,the feedback and evaluation of the optimization of support parameters are carried out.By optimizing the roadway supporting parameters,construction technology and construction process,fully mechanized excavation single entry to 400?450 m/month,and has a capacity of more than 500 m/month.