岩体开挖爆炸应力损伤范围研究

STUDY ON STRESS DAMAGE ZONE IN EXCAVATION OF ROCK MASS

近年发展起来的爆破损伤模型虽能客观反映岩石爆破物理过程,但爆破损伤模型参数选取复杂,需要通过数值计算来确定爆破损伤范围,不便于工程操作。在工程实践中,通常采用萨氏安全判据和PPV安全判据等确定爆破损伤范围,但这些基本上都是半经验判据,在质点峰值振动速度选取上存在人为误差。在分析这些经验判据的基础上,根据爆炸应力波衰减规律,推导爆炸应力损伤范围计算公式,并将上覆岩体的原岩应力作用计入,只要知道岩体抗拉强度、泊松比就可方便预测爆破岩体损伤范围,使其更符合工程实际,并用工程实例计算说明其合理可行,且操作方便简单,具有重要推广价值。

The control of blasting damage is an important research subject in the field of rock blasting.The model of blasting damage recently developed can reflect the physical course of rock blasting objectively,but the model parameters of blasting damage is very difficult to select,and numerical calculation is needed to determine the range of blasting damage,so it is very inconvenient to use.In practice,the range of blasting damage is confirmed by Sach′s safety criterion,peak particle vibration velocity safety criterion and other criterions,however,they are all semi-empirical with man-made error of selecting peak particle vibration velocity.Based on the analysis of empirical criterions and the attenuation rule of blasting stress wave,the range of blasting damage equation to calculate the blast-induced damage zone is deduced and the initial stress of rock is considered.The range of rock damage can be predicted conveniently by knowing the tensile strength and Poissson′s ratio to coincide with practice better.Finally the method of damage calculation is adopted to compute the practice case of a project,and the results show that it is reasonable.The process of operation is convenient,and is worth of spreading in project.