Study On The Surrounding Rock Control Technology Of Gob-side Entry Retaining Under Goaf In Deep Mine At Pangzhuang Coal Mine

Studied on the influence of the upper coal seam mining and different depth on the surrounding rock stability of gob-side entry retaining, the stress and deformation distribution law of deep Gob-side Entry Retaining, surrounding rock control technology at deep mine Gob-side Entry Retaining, by comprehensive using of theoretical analysis, numerical simulation and combined wit h the method of industrial test. And then determined the parameters of roadway-in support, roadside support and strengthen support skills. Main results are as follows:(1)After the upper coal seam mined, the stress of the coal and rock under the coal in front of the working face was larger,due with the influence of upper coal abutment pressure. The stress of the coal and rock under the goaf behind the working face was lower,because of the pressure relief effect of the goaf. Before and after the upper coal mined, the coal and rock under the coal had suffered the process of stress rise rapidly and then drops rapidly, easy to cause the floor strata damage.(2)The deeper the embedded depth of coal seam, the greater the deformation of surrounding rock of Gob-side Entry Retaining, the higher the stress, the greater the distribution area of the plastic zone. Besides, the deeper the embedded depth of coal seam, The greater the damage depth of the floor caused by the upper coal seam mined, the greater the influence on the stability of surrounding rock of the lower coal.(3)Study and analysis of surrounding rock movement rules of deep Gob-side Entry Retaining after the coal mined.The rock of the roof of Gob-side Entry Retaining had suffered twice mining- induced stress, become quite broken, should strengthen the supporting of roof. Besides,the fracture gob roof had formed a stable structure under the support of roadside, roadway- in strengthen support and the coal sidewall.Became the theory foundation for the success of Gob-side Entry Retaining.(4)Combined with the foregoing chapters, studied on the surrounding rock control technology of Gob-side Entry Retaining and determined the parameters of roadway-in support, roadside support and strengthen support skills.The above results were applied successfully in the field test of 95210 working face at Zhangxiaolou mine of Pangzhuang.