Open-pit slopes contain numerous nonpenetrating, intermittent joints which maintain stability under blasting operations. The tip dynamic response coefficient (DRC) of parallel cracks in a typical rock mass under combined dynamic and static loading conditions was calculated in this study based on the superposition principle. The dynamic response law of the intermittent joint in the slope under blasting was determined accordingly. The influence of many factors (the disturbance amplitude of dynamic load, the lateral confining pressure, the length of rock bridge, the length between cracks, the staggered distance between cracks, and the crack inclination angle) on the dynamic response was theoretically analyzed as well. The ABAQUS numerical assessments were conducted on simulation models with parallel cracks under combined dynamic and static loading conditions. The results show that a larger dynamic load amplitude and smaller crack inclination angle/confining pressure result in greater Type II dynamic strengthening effect on the crack tip. When the length of the rock bridge between cracks ( ) is smaller than the half length of the crack ( ), the dynamic strengthening effect at the crack tip weakens gradually with increase in ; when , the strengthening effect is almost unchanged. With the increase in the staggered distance between cracks ( ), the dynamic strengthening effect of the crack tip weakens at first and then strengthens; the strengthening effect is weakest when ; the crack propagation under combined dynamic and static loading is the most sensitive to the lateral confining pressure ( ) and is the least sensitive to the inclination angle of the cracks ( ). Theoretical results are validated by comparison with numerical simulation results. Such information regarding the dynamic response law of the parallel cracks in rock masses under dynamic and static loading conditions is conducive to further research on the mesofailure mechanism of open-pit mine jointed rock slopes under blasting operations.

中文翻译：

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动静联合加载下含平行裂缝岩石动力响应数值分析

露天边坡包含许多非穿透性、间断性接缝，可在爆破作业中保持稳定性。本研究基于叠加原理计算了典型岩体在动静联合加载条件下平行裂缝的尖端动力响应系数（DRC）。据此确定了爆破边坡间断节理的动力响应规律。理论分析了动荷载扰动幅值、侧围压、岩桥长度、裂缝间距、裂缝间距、裂缝倾角等多种因素对动力响应的影响. ABAQUS 数值评估是在动态和静态加载条件下对具有平行裂纹的模拟模型进行的。结果表明，较大的动载荷幅值和较小的裂纹倾角/围压导致裂纹尖端的II型动态强化作用更大。当裂缝间岩桥长度（ ）小于裂缝长度（ ）的一半时，裂纹尖端的动态强化作用随着 的增加而逐渐减弱；时，强化效果几乎不变。随着裂纹间距( )的增加，裂纹尖端的动态强化作用先减弱后增强；强化效果最弱时；动静联合载荷作用下的裂纹扩展对侧向围压（ ）最敏感，对裂纹倾角（ ）最不敏感。通过与数值模拟结果的对比，验证了理论结果。这些动态和静态加载条件下岩体平行裂缝动力响应规律的信息有利于进一步研究爆破作业下露天矿节理岩质边坡的细观破坏机制。