岩体中爆腔内压力脉动特征和爆炸能量分布的数值模拟

Numerical simulation of pulsation features of pressure in explosion cavity and distribution of explosive energy in rock blasting

分析了对岩体中爆炸能量分布和爆腔内压力研究的现状,为进行这方面的研究,在块体离散元基础上独立开发了可变形多尺度计算模型和爆源模型,改进后的数值模型适合研究爆源近区的爆炸效应。通过该模型对岩体中爆腔内压力和爆炸能量分布进行了数值模拟,分析了爆腔内压力脉动特征,指出爆源近区岩体结构性质对爆腔内压力脉动规律影响不大,爆腔内压力峰值与炸药量无关;结合热力学和弹性力学知识分析了不同条件下爆炸能量分布规律,研究了岩体破坏对爆炸能量分布的影响,给出了岩石断裂破坏消耗能量、变形能、用于抛掷的能量的比例。

The research status of explosive energy and explosion cavity in rock blasting is analyzed.The computation models of independent development based on the rigid block discrete element method are introduced,including deformed block model,multi-scale model and explosion source.The improved numerical model is suitable for studying the explosion effects in the near-source region.The pressure of explosion cavity and distribution of explosive energy in rock blasting are simulated.According to the simulated results,the pulsation feature of pressure in explosion cavity is obtained.It is pointed out that the rock structure in the near-source region has the little effect on the pulsation pressure in explosion cavity,and that the pressure peak in explosion cavity has nothing to do with the explosive charge.On such a basis,the theory of thermodynamics and elastic mechanics is used to analyze the distribution rules of explosive energy.The influences induced by the failure of rock mass on the distribution of explosive energy are discussed.Finally,the proportion of energy used to fracture rock,deform rock and throw rock block is proposed.