Study On Energy Dissipation Law And Support Regulation Technology Of Roadway Failure Surrounding Rock

Coal-rock mass failure is the state instability phenomenon driven by energy,and describing the failure characteristics of surrounding rock from the aspect of energy is one of the effective ways to evaluate the roadway stability.By circular roadway elastic-plastic analysis equations based on equal pressure in double perpendicular direction,comprehensive application of laboratory mechanical test,theoretical analysis and field industrial test and other methods,take time as the axis,the dissipated energy of surrounding rock(DESR)was characterized by the strain energy difference of completely elastic region and elastic-plastic region.According to the comprehensive analysis of theoretical model,laboratory test and underground observation feedback,the key indexes of influencing factors of roadway support were given.Based on tension diffusion principle in bolting support,the supporting regulation effect on energy evolution of surrounding rock was studied,and the energy criterion for supporting to control surrounding rock stability was established.The specific contents are as follows:(1)Based on moercullen strength criterion,the mechanical parameters of roof rock samples of 10# coal seam in the first mining area East of Jiegou Coal Mine were analyzed theoretically by means of indoor rock mechanics test and theoretical calculation.Longitudinal splitting was the main failure mode in the test.According to The BQ classification of surrounding rock,the surrounding rock of roadway in 10#coal seam was divided into grades.The coarse siltstone and fine siltstone in the roof of 10# coal seam were divided into class III and class V of fine sandstone.(2)By circular roadway elastic-plastic analysis equations based on equal pressure in double perpendicular direction,take time as the axis,the dissipated energy of surrounding rock(DESR)was characterized by the strain energy difference of completely elastic region and elastic-plastic region.Based on the calculation process of roadway DESR,the influence of initial stress,roadway radius and surrounding rock strength(cohesion and internal friction Angle)on DESR was analyzed.At the same time,the radius of engineering disturbance would shift outward after the plastic failure of roadway occurred.And stress redistribution resulted in the transfer of energy to the stress region of the original rock(3)According to the calculation principle of bolting support and roadway DESR,in the condition of "support-rock" coordinated deformation,the equations of the bolt support structure of energy absorption and the limit of energy storage were given.The effects of bolt supporting parameters(bolt diameter,row spacing,pretightening force,bolt length and anchor length)on DESR were analyzed.The energy criterion for rock bolt support to control surrounding rock stability was established and the roadway support parameters were inverted(4)The bolting supporting parameters of test roadway were determined.The field industrial test had been carried out in the 1025 working face of 10# coal seam in the first mining area East of Jiegou Coal Mine.The results of underground monitoring verified the rationality and reliability of the research.The energy dissipation law of roadway failure surrounding rock and support regulation technology were systematically studied,which provided a new way for the design of key parameters of bolt support and a new method for coal mine roadway under relevant geological conditions.There are 57 figures,27 tables and 80 references.