Study On Grouting Reinforcement Technology Of Roadway Under Twice Mining Disturbance In Wangpo Mine

The surrounding rock strength of 3213 transportation roadway in Wangpo Mine is low,the coal body is broken,the joint fissures are developed,and during the service period,it must bear the influence of the upper section and the working face in this section.In this paper,the transportation roadway is taken as the research object,and the deformation mechanism and grouting reinforcement technology of surrounding rock of the mining roadway affected by twice dynamic pressure are studied by theoretical analysis,numerical simulation and industrial test.The main research results are as follows:(1)The development degree and range of the surrounding rock fracture of the roadway after the influence of a mining are proved by using the drilling exploration method.The results show that the development degree of the shallow surrounding rock fracture is the highest,with the increase of the depth,the number and development degree of the fracture gradually decrease,and the fracture range of the two sides of coal is about 5.5m.(2)The characteristics of surrounding rock structure change,stress concentration and plastic zone distribution under the influence of two times mining are clarified.Under the influence of first mining,the basic roof lateral fracture position of the roadway is above the coal pillar,and the deformation of the surrounding rock increases under the action of lateral support stress;under the influence of secondary mining,the roadway is in the area of stress superposition,and the deformation of the surrounding rock increases rapidly under the action of advanced support stress,which shows that the roof sinks,the two sides move near and the floor blows up,and the surrounding rock stress environment is further deteriorated,The scope of plastic zone is obviously enlarged,and the stability of surrounding rock of roadway is sharply reduced.(3)According to the influence of two mining operations on the surrounding rock structure and deformation characteristics,three grouting schemes are proposed,including deep and shallow surrounding rock grouting,It shows that the maximum deformation of the roof and floor of the roadway and the two gangs when using the "7 m grouting anchor cable and grouting pipe grouting in the roof + two sides made use of 6 m grouting anchor cable and grouting pipe grouting and reinforcing anchor cable reinforcement" scheme It is 389 mm and 234 mm,which are reduced by 42.11% and 60.2% respectively compared with the original support,and the reinforcement effect is the best.(4)The construction scheme and process parameters of grouting reinforcement are determined,and the deformation characteristics of surrounding rock under different grouting timing conditions are compared and analyzed,that is,the conventional grouting reinforcement section: deep grouting is carried out 3-5 days after the completion of shallow grouting;the phased grouting reinforcement section: deep grouting is carried out 80 m ahead of the working face.The results show that the deformation of the surrounding rock of the roadway is within the controllable range.Compared with the conventional grouting reinforcement section,the maximum separation value of the roof and the maximum deformation of the roof,the floor and the two sides of the stage grouting reinforcement section are reduced by 20.6%,30.3% and 23.3%,respectively.The surrounding rock control effect is better.There are 68 figures,6 tables and 91 references in this paper.