Considering the common charging structure and rock mass condition in the drilling and blasting excavation,the refined numerical model is established and the fluid-solid coupling simulation is carried out.Taking the blast hole with axial decoupling coefficient of 1.64 as example,the developing duration for the crushing zone and fracture zone are 100 μs and 500 μs respective-ly and the radii are 3.8 times and 33.4 times of hole radius.Focusing on the radial pressure history at efficient radius (the boundary between crushing zone and fracture zone),the peak radial pressure reaches 296 MPa and then decays along radical di-rection with its decaying coefficient of-0.87.Furthermore,the other 4 kinds of blast hole with different axial decoupling coeffi-cients are also studied by the similar numerical simulations.The peak radial pressure at the efficient radius will decrease expo-nentially with the radial decoupling coefficient and the theoretical-empirical formula is proposed.The research results provide some basis for the determination of equivalent blasting load.%针对钻爆法施工中常见的炮孔装药结构和围岩条件,建立相应的数值模型,对单孔爆破进行流固耦合的精细化数值模拟.以轴向不耦合系数KL=1.64的炮孔为例,设其粉碎区和破裂区的形成时间约为100μs和500μs,半径分别为炮孔半径的3.9倍和35倍.当炮孔有效半径(近似粉碎区与破裂区交界处)上径向压力时程的峰值达到296 MPa时,沿着径向呈指数型衰减,其衰减系数α约为-0.87.进一步地,对其余4种不同轴向不耦合系数的炮孔,也展开类似的精细化数值模拟.认为有效半径Req上的径向压力峰值peq随不耦合系数KL的增大呈指数型衰减,并提出了相应的半理论半经验公式.研究结果为进一步确定等效爆破荷载提供了重要依据.
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