Study On Support Technology Of The Auxiliary Haulage Roadway Of NO.2 Coal Group Under The Condition Of Water Rock Stratum In Lijiata Coal Mine

In the process of roadway excavation,the auxiliary haulage roadway of NO.2 coal group under the condition of rock stratum in Lijiata Coal Mine,because There is water in the surrounding rock of the roadway,the cementation,bearing strength and other mechanical properties of the surrounding rock are relatively weakened,on site construction is particularly concerned about the safety of roadway surrounding rock support stability under the condition of water strata.In view of the safety problem of roadway support under water rock stratum in Lijiata Coal Mine.First of all,through on-site investigation,this paper understands the stress and deformation characteristics of surrounding rock under the condition of rock stratum,and the construction effect of roadway excavation in water rock stratum.Taking the auxiliary haulage roadway of No.2 coal croup in Lijiata Coal Mine as the research object,the stress,deformation and failure characteristics of surrounding rock of roadway under water rock stratum and anhydrous rock stratum are compared and analyzed through numerical simulation,and the influence of water rock stratum condition on the safety of roadway surrounding rock is revealed.On this basis,the mechanical theory analysis of the influence of the strength weakening and instability of surrounding rock under the condition of water rock stratum is carried out.It provides a theoretical reference for the surrounding rock control analysis and roadway support design analysis of No.2 coal group auxiliary haulage roadway under the condition of water bearing strata,and then guides the research on the surrounding rock control and support control scheme of auxiliary haulage roadway of No.2 coal group under the condition of water rock stratum in Lijiata Coal Mine.Finally,the control scheme of surrounding rock control and support for auxiliary haulage roadway of No.2 coal group under the condition of water rock stratum in Lijiata Coal Mine is put forward,the reasonable support design parameters are determined through the calculation of surrounding rock failure of auxiliary haulage roadway of No.2 coal group under the condition of water rock stratum;then,numerical simulation is adopted to analyze and verify the supporting effect of the auxiliary haulage roadway of No.2 coal group under the condition of water rock stratum;finally,on-site deformation monitoring is carried out,and the support effect is evaluated according to the field monitoring feedback.Through the study of this paper:(1)through field investigation and numerical simulation,it is concluded that the mechanical properties of roadway surrounding rock are weakened under the condition of water rock stratum,furthermore,the weakening effect of water in the surrounding rock on the surrounding rock is mainly reflected in the obvious increase of the damage degree of the surrounding rock;(2)theoretical analysis shows that the surrounding rock of roadway under water rock stratum condition is relatively sensitive to various influencing factors,besides the increase of original rock pressure and water permeability coefficient of surrounding rock has obvious influence on the instability of surrounding rock,so the key of roadway stability control is to improve the bearing capacity of surrounding rock and reduce the influence of water on surrounding rock by technical means;(3)based on the analysis of surrounding rock control of roadway under water rock stratum,the control ideas of roadway surrounding rock under water rock stratum are as follows: strengthening roadway support strength,optimizing roadway section,improving mechanical conditions of roadway surrounding rock,timely taking water diversion measures;(4)This paper puts forward the combined support scheme of "high prestressed high-strength bolt + anchor cable coordinated support + concrete shotcreting" for the engineering condition of auxiliary haulage roadway of NO.2 coal groups under the condition of water rock stratum,the site monitoring feedback of the auxiliary transportation roadway of No.2 coal group shows that the control is stable and the support effect reaches the expected requirements.