Study on principle application of energy absorption and bump reduction of high impact toughness rock bolt

In order to solve the support problem of rock burst roadway in Changcun Mine of Yima Mining Area, the surrounding rock failure characteristics of rockburst under bump load were analyzed. It revealed that the essence of rockburst damage to support structure is that bump load deteriorates the mechanical properties of anchor rod, tears the metal mesh and reduces the anchoring performance of the anchoring system. Aiming at the failure mechanism of surrounding rock in rockburst roadway, the 600 MPa high impact toughness bolts were developed, the breaking strength of the high impact toughness bolt reached 850 MPa, and its energy absorption capacity and instantaneous elongation were 1.32 and 1.33 times higher than those of ordinary bolt respectively. The high-toughness anchor bolt can absorb impact energy by improving the strength, stiffness and energy absorption characteristics of support system. This can greatly improve the impact resistance of the supporting system, and absorb the energy released by the impact ground pressure through the supporting system, and reduce the damage effect of residual energy on the surrounding rock of the roadway. The research results have been tested in Changcun Mine of Yima Mining Area. After the high impact toughness bolt support system has been subjected to multiple large energy impact loads, the bolts and anchor cables are subjected to zigzag fluctuations, and the support structure effectively controll the deformation and damage of the roadway under impact.