Study on dynamic response characteristics and damage law of anchor bolts in coal mine roadway under rock burst
SUN Huaiming
LI Wenzhou
LI Zhongwei
CHU Peng
SUN Yue
LI Xiang
Abstract：Aiming at the problem of frequent occurrence of rock burst disaster in deep coal mine roadway and unclear dynamic re-sponse mechanism of anchor bolt support,we adopt numerical simulation and field test to systematically analyze the mechanical re-sponse characteristics and damage law of anchor bolts with different impact toughness under dynamic load;based on LS-DYNA software,the impact model of anchor bolts was established,and the dynamic response of anchor bolts with yield strength of 500 MPa and impact absorbed work of 15-94 J under 20 ms isosceles triangle load was simulated.By analyzing the Mises stress distribution,fracture characteristics,displacement change and energy absorption law of the anchor bolts,the mechanism of impact toughness on the damage mode of the anchor bolts was revealed,and applied to the design of anchor bolt support in Tangkou Coal Mine 7307 track roadway.The results show that with the increase of impact toughness,the Mises stress at anchor bolt fracture increases,and the fracture necking phenomenon is significantly enhanced;the higher the impact absorption work of the anchor bolt under the same im-pact load,the higher the displacement at fracture,to cause an anchor bolt with high impact toughness to break within a fixed impact time,high impact loads need to be applied.The higher the impact load the greater the deformation rate of the anchor bolt in the plastic deformation stage,resulting in the anchor bolt breaking without giving full play to the deformation capacity,there will be a high impact toughness and low elongation of the anchor bolt.The deformation of the anchor bolt increases with the decrease of dis-tance from the impact load application,but it does not change much in the range of 1.5 m from the fixed end,the study further re-veals the local effect of anchor bolt deformation,in the range of 1.5-2.0 m from the impact point,the deformation increases 50%compared with the section of 1.0-1.5 m,and the plastic strain firstly occurs in the fixed end and extends to the impact point,and fi-nally destroys centrally in the threaded section.
Keywords：anchor bolt supportnumerical simulationrock burstdynamic response characteristicimpact toughness
Publication Date：2025-11-20
Online Publishing Date：2025-11-25(First online date of this platform, not the publication date of the document)
Pages：11( 64-74 )