Deformation mechanism and stability control of repeated mining roadway

In the process of high intensity mining,the stability control of surrounding rock of mining roadway is very important.Aiming at the deformation characteristics of surrounding rock of mining roadway under strong mining in fully mechanized caving face of thick coal seam in Buertai Coal Mine,taking 42203 fully mechanized caving face as an example,according to the butterfly failure theory of surrounding rock of roadway,combined with numerical simulation method,the deformation mechanism of surrounding rock when the auxiliary transportation gateway is affected by primary and secondary mining is studied,and the "butterfly" expansion mechanism of plastic zone of surrounding rock of roadway is analyzed.The results show that the plastic zone boundary of roadway surrounding rock is related to the buried depth,lateral pressure coefficient and mechanical properties of surrounding rock;the ratio of confining pressure determines the development form of plastic zone of surrounding rock.Under the influence of mining,the size and direction of the maximum and minimum principal stress around the roadway are constantly changing.The stress of auxiliary transportation crossheading of 42203 working face is deflected when affected by mining,resulting in asymmetric expansion of plastic zone.Based on the distribution law of mining-induced stress and the evolution law of plastic zone in auxiliary transport crossheading of 42203 working face,the corresponding technical scheme of strengthening support for surrounding rock control is put forward.The field industrial test results are good,which provides some reference for the deformation mechanism and stability control of surrounding rock in repeated mining roadway.