Analysis on control efficiency of impact instability anchor in thick coal seam roadway based on energy principle

Bian Yongtian; Wang Jun; Zhou Shuai; Zhang Shuai; Hu Yabo; Sun Kai

doi:10.19896/j.cnki.mtkj.2025.02.018

Abstract：Anchor supporting is an important means to prevent the impact of rock burst roadway,especially the deep well thick coal seam dynamic loaded roadway puts forward higher requirements on the impact resistance of roadway anchor supporting system.Firstly,taking the mining technology and geological conditions of the No.4402 working face return airway in a mine in Shaanxi as the background,a structural model of impact instability of anchored surrounding rock in the thick coal seam roadway was established based on the energy principle,and the energy criterion of catastrophic instability was deduced,which is to consider that the ratio of the residual elastic strain energy to the induced impulse energy of the anchored surrounding rock after the impact instability is greater than 1;secondly,the quanti-tative contribution and sensitivity of anchoring parameters to control the start of thick coal seam roadway impact instability were analyzed by using the single-factor and global sensitivity analysis method;finally,the anchor prevention and control technology strategy for deep thick coal seam roadway was proposed and put into engineering practice.The research results show that the superposition and release of static load storage energy of surrounding rock and external disturbance energy is the driving force of impact instability,but the kinetic energy formed by the release of the remaining elastic strain energy converted after the instability of the anchored surrounding rock is a sufficient condition for the emergence of the impact instability;the quantitative analysis reveals that the anchoring parameters of the an-chor rods(cables)number,diameter,strength,length and end anchoring have positive effects on the control of the impact instability of the roadway.However,the factors of anchor cable number,length,diameter and anchor diameter and number are highly sensitive factors for its control effect;the anti-impact effect of the number and diameter of anchor rods(cables)is mainly based on the deformation of the anchor rod(cable)body and the energy dissipation caused by the failure of the anchoring structure,followed by the reduction of the static load energy of the surrounding rock;the anti-impact performance of the yield strength,length,anchoring method and pre tension is mainly based on the free section deformation and energy dissipation of the anchor.