Study on the influence of ground stress on liquid CO2 phase transition blasting damage and vibration effects

WANG Yan

doi:10.13347/j.cnki.mkaq.20231930

Abstract：In order to reveal the influence of ground stress on the crack extension and vibration effect of CO2 phase change blasting,the crack extension characteristics and vibration effect of CO2 phase change blasting under different ground stress conditions were in-vestigated based on LS-DYNA numerical simulation software.The results show that under the action of equal biaxial ground stress,the fracture zone and crushed zone produced by CO2 phase change blasting are circular,with the increase of ground stress,the radius of the fracture zone shows a tendency of rapid decrease and then slow decrease,and the radius of the crushed zone shows a tendency of decreasing and then stabilizing;under the anisotropic ground stress,the expansion of the fissure zone is elliptical,and the cracks preferentially expand in the direction of the maximum principal stress;the velocity time course curve shows a bimodal oscillation structure,and under the action of isotropic biaxial ground stress,the first velocity peak gradually decreases and the second velocity peak gradually increases with the increase of the ground stress;under anisotropic ground stress,the first peak velocity gradually de-creases in the horizontal direction with the increase of lateral pressure coefficient;in the vertical direction,the first peak velocity gradually increases;the asymmetric release of strain energy in the rock mass generates SH waves.