Research on deformation characteristics of surrounding rock and pre-tightening force design of bolt supporting in"three soft"coal seam roadways
Ge Kai
Shen Chengyang
Feng Haiming
Wang Xufeng
Liu Changcheng
Abstract：To solve the problem of large deformation and prolonged deformation of surrounding rock in"three soft"coal seam roadway of Tianshuibao Coal Mine,the deformation mechanism of surrounding rock was mastered through on-site observation,laboratory testing,and numerical simulation.The influence of anchor bolt pre-tightening force on roadway supporting effect was clarified,and a reasonable pre-tightening force was determined.The research results indicate that the surrounding rock of"three soft"coal seam roadway in Tian-shuibao Coal Mine contains over 30％clay minerals,which are prone to mud deformation when exposed to water.The low strength and weak bearing capacity of surrounding rock are the main reasons for large deformation of the roadway.According to numerical simula-tions,the roof subsidence decreases by 21.3％,23.7％,and 12.1％respectively when the pre tensioning force of the anchor rod is 50,70,and 90 kN.When the pre-tightening force exceeds 70 kN,further increasing the pre-tightening force will significantly weaken the control effect on surrounding rock.Therefore,the reasonable pre-tightening force of anchor bolt is determined to be 70 kN.The industri-al test results show that by improving the supporting system and increasing the pre-tightening force of anchor bolt to 70 kN,the deform-ation of roadway is effectively controlled.
Keywords："three soft"coal seambolt supportingpre-tightening forcenumerical simulation
Publication Date：2025-10-30
Online Publishing Date：2025-11-27(First online date of this platform, not the publication date of the document)
Pages：8( 76-83 )