Research On Optimization Of Support Parameters In Large Cross-section Transportation Of Ning Tiao Ta Coal Mine

At this stage,coal resources are still an important guarantee for China's rapid economic development.As a commonly used support method in coal roadway in China,bolt(cable)support has achieved certain achievements in theoretical research and field construction.However,with the complex changes in the conditions of coal seams and the increase in the size of roadway sections,the bolts(cables)support of the existing roadway gradually exposed various problems;Therefore,the support design scheme must be optimized to ensure the safety and smoothness of coal mining activities.This paper takes the engineering background of failure strain of the transport N1206 Ning Tiao ta Coal Mine,analyzed the mechanism of the bolt(cable)and the design concept,the reason of roadway instability and deformation;Combined with field monitoring data,the original support design of the transportation chute are analyzed with reference to the finite difference method.Based on the self-stabilized hidden arch theory,optimized the original support design,and two sets of schemes are proposed as the comparison.Three kinds of support schemes are calculated and analyzed by FLAC3D numerical simulation software,and the most reasonable support design scheme is found according to its supporting effect,selected 50m as the test section in the transport N1206,checking the supporting effect of the optimized design.The on-site monitoring data of the test section is as follows:The average value of the roof sinking is 33mm,which is 227.75mm smaller than the original plan;the average value of the band's convergence is 8.75mm,which is 500.45mm less than the original plan.It shows that the optimized supporting scheme can help the roadway surrounding rock to exert its own bearing capacity and improve the ability of anti-deformation and anti-damage of roadway surrounding rock,and can maintain the roadway stability under the lower support cost.It also verifies the rationality of anchor parameter design under the guidance of the self-stabilized hidden arch theory.The research process and results of this paper can be used as an important reference for the design of other roadway support in this mine.and provides reference for the design of other similar roadway bolts(cables).