Study On The Surrounding Rock Stability Characteristics And Control Method In The Roadway Junction

The roadway junction is the key supporting part of the development roadway in the coal mine, In the process of the roadway junction construction, because the surround rock of the roadway junction has the big span roof and the characteristics of high stress concentration factor,so the surround rock of the roadway junction tends to happen failure, on the basis of predecessors’research, Through the theoretical analysis and numerical simulation methods this article studied the failure characteristics of surrounding rock of the roadway junction, the maximum damage depth of surrounding rock, the stress distribution of surrounding rock, the surrounding rock control method, and on the basis of the roadway junction of the south railway haulage crosscut and the No2shunting siding in Yangquan coal group. the supporting method of anchor-plate retaining is designed, at last, the support is verified reasonable through the field monitoring and date feedback,After a series of studies, this thesis have mainly known is as follows:1、Combining with the Coulomb-Mohr strength criterion, This thesis analyzed the surrounding rock stress distribution and failure characteristics in the field of the roadway junction,the damage form of the roadway junction is obtained and the form appears to the approximate curved edge triangle distribution,meanwhile the conclusion which the characteristics triangle area of surrounding rock stress concentration phenomenon is obvious is obtained,finally, when supporting the roadway junction, the triangle area, the roof and the surrounding rock within the scope of influence in intersection need to focus on strengthening。2、 Using the elastoplastic limit equilibrium, the corner of the maximum damage depth of surrounding rock are derived in the roadway junction,through the analytic expression, the maximum damage depth of influence factors are:the original rock stress, section size, cross Angle, the strength of surrounding rock.3、Through the ANSYS numerical simulation software analyzed the characteristics of surrounding rock stress distribution and displacement variation in different cross angle, section size, buried deep under the condition of roadway junction, and summarizes the rule of cross angle, section size, buried deep influence on the stability of surrounding rock of roadway junction.4、Points out the acute triangle region and obtuse triangle regions surrounding rock area ratio is an important factors to the roof subsidence of the roadway junction, put forward the ratio of the two can be estimated as one of the important indicators to the character of the roadway junction such as stress concentration, unloading zone thickness, displacement changes.5、This thesis systemic analysis the geologic factors and the non-geologic factors which affect the stability of surrounding rock of the roadway junction and summed up the suitable control theory for the surrounding rock of the roadway junction. they main include the surrounding rock supporting joint bearing theory, the key parts to strengthen the supporting theory, the whole anchorage support theory, the coordination theory of primary and secondary.6、Based on Primary and secondary coordinate supporting theory,the thesis analyzed the dynamic change process of the abutment pressure and the plastic zone size within the triangle area of the surrounding rock in the roadway junction.It determined the triangle area of the surrounding rock needs to strengthen in the early support.7、The anchorage scheme and anchor parameters and the mine pressure monitor were carried out to the roadway junction of the south railway haulage crosscut and the No2shunting siding in Yangquan coal group. at last, the observation results show that the support method can effectively control the roadway surrounding rock deformation and failure, meanwhile the method can realize the aim of the surrounding rock stability control in the roadway junction.