Research And Application Of Surrounding Rock Decompression And Anchorage Control Technology In Suncun Kilometer Deep Mine Roadway

The exploitation of deep coal resources has become normalized,and the control of surrounding rocks in deep roadways needs to be solved.The thesis takes the Suncun Mine's buried depth of 1300 meters and a half coal and rock roadway as the research object,and adopts the research methods of field investigation,laboratory experiment,theoretical analysis,numerical simulation and industrial experiment.The roadway surrounding rock control concept of "prestressed full-length anchoring-grouting reinforcement-transfer of high stress".The main research results and conclusions are as follows:(1)Analyze the support difficulties and the causes of deformation and damage.Investigate roadway support and engineering geological conditions.The deformation of the roadway is mainly concentrated on the high side and floor;through field sampling,laboratory preparation and testing,the relevant mechanical property parameters of the roadway roof and floor rocks are obtained.The maximum compressive strength is39 Mpa.It shows that although the roof and floor of the roadway are siltstone,the mechanical properties are poor,which is the internal reason for the deformation and failure of the roadway.The external reasons are mainly high in-situ stress and low anchoring depth of the bolts,which cannot restrain the continuous deformation of the surrounding rock under high ground stress.(2)The stress distribution law of surrounding rock in deep roadway is revealed.By establishing a trapezoidal roadway model,using complex variable functions to derive the formula for the stress distribution law of the trapezoidal roadway surrounding rock,the trapezoidal roadway stress deformation has asymmetric characteristics;using numerical simulation to analyze the influence of the buried depth and the lateral pressure coefficient on the roadway stress distribution law,As the buried depth increases,the concentrated stress at the side of the roadway will increase.When the lateral pressure coefficient is 1,the maximum concentrated stress is 41 MPa and greater than the strength of the surrounding rock.As the lateral pressure coefficient increases,due to the soft coal,the overall deformation of the roadway is transferred from the sidewall to the floor.The roadway as a whole shows the characteristics of high stress,and the high stress and broken surrounding rock increase the difficulty of controlling the roadway.(3)The mechanism of drilling pressure relief under high stress conditions is analyzed.Based on the high stress characteristics of the roadway,numerical simulation studies the mechanism of borehole stress relief,and proposes to use borehole stress relief technology to optimize and improve the surrounding rock stress environment.The distribution of plastic zone and stress zone of the roadway under the influence conditions of borehole length and diameter are analyzed through theoretical and numerical simulation,and the reasonable range of borehole pressure relief parameters is determined.(4)Clarified the advantages of high-prestressed full-length anchor bolts and grouting reinforcement.According to theoretical analysis and numerical simulation,the high-prestress full-length anchoring support changes the mechanical properties of the shallow broken surrounding rock of the deep roadway under external conditions;the high-strength hollow grouting anchor cable fundamentally changes the grouting reinforcement of the roof and coal bank.The mechanical properties of the surrounding rock of the roadway enable the shallow surrounding rock of the deep roadway to form a shallow bearing structure under the action of high pre-force full-length anchoring and grouting reinforcement,which enhances the stability of the shallow surrounding rock and effectively realizes the control of the shallow surrounding rock.At the same time,theoretical analysis and geological conditions are combined to determine reasonable grouting reinforcement parameters.(5)The rationality and scientific nature of the support plan was verified.Based on the above research results,a "high prestressed full-length anchor bolt + high-strength hollow grouting short anchor cable + borehole pressure relief" asymmetric roadway surrounding rock control technology is proposed.Numerical simulation research shows that the new support plan is more reasonable than the original support plan.Use the new support plan to carry out support tests in the roadway,and use the surrounding rock displacement sensor and the surface roadway surface maintenance effect to verify that the new support plan can effectively suppress the expansion of the plastic zone and the deformation of the roadway surrounding rock,and ensure the stability and safety of the roadway.The paper has 62 pictures,15 tables,and 93 references.