Research On Design And Application Of Roadway Bolt Supporting Based On Group Anchor Bearing Capacity

Roof fall is one of the common safety accidents during roadway excavation and mining.Every accident will affect the normal production of underground mines.In order to better protect the safety,production and operation of personnel and equipment below the well,and reduce unnecessary losses,the research on the mechanism of tunnel collapse and early warning technology is of great significance.The thesis uses the S1231 auxiliary transportation channel of a coal mine as the research background,and conducts scientific research with a combination of theoretical analysis,numerical simulation,and field tests,and studies the failure modes and mechanical analysis of single bolts and group bolts;Based on the calculation of the existing roadway and the newly excavated roadway,the stability of the roadway and the design of bolt support are studied using the upper limit theorem.The main research results are as follows:(1)The group-anchor effect has a restraining effect on the surrounding rock of the roadway,forming an anchor bearing ring and layered bearing effect,and has a wedging effect on the loose broken rock mass.According to the damage characteristics of the surrunding rock,a linear failure mechanism is established:based on the Mohr-Coulomb failure criterion,the internal energy loss power before and after the roadway surrounding rock failure and the power made by the external force are calculated,and the velocity discontinuity line function is obtained;The calculation formula of the ultimate bearing capacity of single bolt and group bolts is deduced by the law of conservation of energy,and the ultimate supporting capacity of the available roadway is deduced.(2)Study the process of plastic flow failure of rock-soil structures,calculate and derive the external force power and internal energy power under this motion according to the limit upper limit analysis method,study the stability of surrounding rock designed by the upper limit analysis method,and the displacement and displacement of surrounding rock cave The plastic zone range of the surrounding rock is used to obtain the stability coefficient of the surrounding rock.The support effect is evaluated by analyzing the support parameters of the surrounding rock of the roadway,to determine whether the roadway is stable,and to discuss whether the method is good for evaluating the stability of the surrounding rock of the roadway.(3)According to the theoretical support design plan,the auxiliary transportation channel of S1231 working face of a coal mine was designed with group anchor support.The motion simulation software modeling and analyzing the stress,displacement field and deformation law of the surrounding rock of the roadway under different support parameters,as well as the influence relationship between the parameters of the bolt and the deformation index of the surrounding rock,verify the accuracy of the theoretical derivation of the thesis,and Adjust reasonable bolt support parameters according to the roadway support effect.(4)Based on the actual measurement and analysis of the S1231 auxiliary transportation channel of a coal mine,combined with the actual measurement data,the surrounding rock stability coefficient evaluation method is used to evaluate the traditional support theory and the support effect designed based on the upper limit analysis method.At the same time,the evaluation results are fed back to the bolt support design to optimize the support parameters of the surrounding rock of the roadway,thereby improving the roadway driving rate and economic benefits.