Dynamic characteristics and control mechanism of anchored rock with constant resistance and energy absorption material

The essence of rock dynamic disaster in deep engineering is the sudden release of accumulated energy of surrounding rock. The effective absorption of energy through anchor support is not only a common means of surrounding rock control, but also is the key of rock dynamic disaster control. The research on dynamic characteristics and control mechanism of anchored rock is the premise of reasonable support design. Based on this, a new type of constant resistance and energy absorption support material with high strength, high elongation and high energy absorption is developed. The dynamic test of anchored rock with constant resistance and energy absorption is carried out. The dynamic response characteristics and energy evolution law of anchored rock is analyzed. The results show that compared with unanchored rock, the surface damage rate and volume damage rate of anchored rock with constant resistance and energy absorption are reduced by 62.1% and 93.1% respectively. Compared with unanchored rock, the fragment weight of medium, fine and microparticles of anchored rock are reduced by more than 90%. Compared with unanchored rock, the total energy, average energy and maximum energy of anchored rock are reduced by 87.6%, 82.9% and 80.3% respectively. The peak stress of anchored rock increases by 54.2% and the rockburst time is delayed by 140.2%. At the same time, the strength, energy absorption capacity and shear migration characteristics of support components are analyzed. The strength, deformation and energy absorption safety reserve rates of constant resistance and energy absorption materials are 38.8%, 94.0% and 97.9%, respectively. The offset of the upper and lower support components of the specimen are 0.886mm and 0.403mm, respectively. Rockburst anchorage control should consider the shear action of surrounding rock. Based on rockburst energy calculation model, the law of peak stress and energy release of rockburst is studied. The control mechanism of prestressed anchorage support on rockburst is revealed. The peak stress of rock burst increases from 1.6 times of uniaxial compressive strength to 2.5 times due to constant resistance and energy absorption anchorage.The energy required for rockburst of anchored rock was 2.3 times that of unanchored rock. Prestressed anchorage support reduces the risk of rockburst effectively. Based on the above research, the engineering suggestions of rockburst prevention and control are put forward from the aspects of monitoring and warning, control methods, support design and effect evaluation.