Research And Application Of Differential Control Technology For Surrounding Rocks Of Inclined Coal Seam Tunnels Under Complex Conditions

Based on the engineering background of the(4-5)06W track run in the sulfur ditch mine,through field investigation,laboratory experiments,theoretical analysis,numerical simulation,and industrial tests,this thesis studies the asymmetric large deformation of roadway surrounding rock caused by the influence of goafs and faults in different areas of the highly inclined roadway surrounding rock,and conducts a differential surrounding rock control scheme design.Based on the interpretation results of seismic data from the frequency resonance profile,the track trench is divided into regions,and the deformation characteristics of surrounding rock in highly inclined seam roadways are studied.The stress distribution and deformation of surrounding rock in the unsupported state of the roadway under the influence of different geological factors are analyzed.The stress and deformation conditions of surrounding rock in different regions of the trench at different stages are studied,and the key deformation areas of surrounding rock requiring enhanced support are determined,Quantify the support effect of the support scheme into the volume of the compressive stress zone it forms,thereby achieving three-dimensional visualization of the support effect,and evaluating the effectiveness of the optimized scheme.Field tests have been conducted to achieve accurate and efficient control of roadway surrounding rock under complex geological conditions in the sulfur ditch coal mine.The main contents are as follows:(1)Based on the interpretation of frequency resonance profile seismic data,the specific location of adjacent goaf areas in the excavation process and the exposed fault positions during the excavation process are explored,and based on this,the(4-5)06W track trough is divided into different regions;(2)Mechanical analysis was conducted on the surrounding rock of inclined coal seam tunnels,and numerical simulations were conducted to study the deformation characteristics of the surrounding rock in various areas without support.The key areas where the surrounding rock is prone to large deformation were preliminarily determined,as well as the deformation characteristics of the surrounding rock in each area.The distribution is asymmetric in both horizontal and vertical directions.(3)Studied the stress distribution,plastic zone range,and deformation characteristics of surrounding rock in different regions and periods of the target channel.The maximum deformation variation law of surrounding rock along the direction of tunnel excavation was studied.The distribution characteristics of advanced support pressure in front of the coal and surrounding rock of the working face during mining were studied.The mining of the working face not only leads to a significant increase in the advance support pressure within a range of about 25 m of the coal body in front of the work face,but also overlaps with the impact of the goaf of the(4-5)04 working face,resulting in a significant increase in the advance support pressure near the goaf.The smaller the distance from the goaf of the(4-5)04 working face,the more significant the superimposed effect.(4)Compare the distribution of effective compressive stress zones generated by anchor rods and cables in different regions between the original plan and the optimized plan,and evaluate the support effectiveness of each plan based on this.In the original plan,the compressive stress zone formed by the roof and side anchor cables was relatively dispersed and could not provide effective support.The optimization plan aims to strengthen the support of key areas with weak support by adjusting the spacing between anchor rods(cables),forming an effective superimposed compressive stress zone in both horizontal and vertical directions in the key areas of the surrounding rock.Finally,by comparing the volume of compressive stress generated by each support scheme under the critical value of significant changes in the compressive stress zone,and introducing a support coefficient to quantitatively evaluate the support effect of the support scheme.The optimization plan not only strengthens the control of local weak areas of surrounding rock,but also significantly enhances the overall support effect of surrounding rock.(5)Industrial tests were conducted on the(4-5)06W work interview tunnel,and the results showed that the development degree of cracks in the surrounding rock was low and there was no trend of extension.The range of coal fragmentation area was small and there were no extension cracks around it.The overall integrity of the surrounding rock was good,and the support system was fully utilized,ensuring the stability of the tunnel for a long time.