Experimental study on dynamic and static performance of a new type of pressure-absorbing energy bolt system

Rock burst support of deep rock mass has always been a difficult problem in geotechnical engineering. Aiming at the problem of rock burst in deep rock mass, a new type of pressure yielding and energy-absorbing bolt system is designed in this paper. The energy absorption characteristics of laminated spring members with different wall thicknesses were studied by the static axial compression test and drop hammer dynamic impact test. The experimental results show that under static axial compression, the laminated spring experiences three stages: elastic, yielding, and plastic strengthening; with the increase in the wall thickness, the energy absorbed by the laminated spring increases gradually. Under the action of impact kinetic energy, with the increase in the wall thickness and impact height, the attenuation time of pressure absorption energy increases, while the tray and nut do not change, and the bolt does not extend and bend. The ANSYS static numerical simulation analysis shows that the center of the top circle of the laminated spring component is the center, and the plastic zone radiates outward; the LS-DYNA numerical simulation shows that most of the impact kinetic energy of the drop hammer is absorbed by the laminated spring component, and the rest is small. The partial energy is borne by the bolt body. Therefore, the laminated spring component can effectively absorb the impact kinetic energy, achieve the effect of active pressure and energy absorption, and avoid the bolt being broken so as to avoid the bolt body bearing all the impact kinetic energy and damage.