岩体中爆破破坏分区研究

Study on Distinction of Blasting Crack Zones and Time Course of Stress in Rocks

文章根据岩体爆破变形与破坏特征 ,利用松散介质力学、连续介质力学和空腔膨胀理论对爆破地震波效应研究中最基本、最重要的基础性工作——震源机制进行了研究 ,提出了确定破坏区发展的动力学计算模型 ,揭示了空腔壁在爆生气体的作用下不断膨胀的脉冲过程 ,给出了破坏区范围大小。数值分析计算实例结果表明 ,花岗岩中空腔区、破碎区、径向裂隙区半径分别为装药半径的 1 .4 8倍～ 1 .84倍、2 .5 4倍～ 4 .70倍和 2 1 .6 0倍～ 2 3.4 4倍 ,与传统概念上的分区大小一致。

According to the characteristics of rock blasting deformation and damage, applying porous and continuous medium mechanics and the theory of cavity expansion, mechanism of blasting vibration source, that is the most fundamental and important basic works in the searches of blasting seismic effects, has been studied in this paper. The dynamic calculation sketch of determining blasting crack zone development is advanced. It is shows pulse course of cavity wall under the explosion gas, and presents the crack limits and the time course of stress on the juncture between crack zones and the elastic vibration zone. The results of numerical calculation analysis indicates the radium of cavity, breakage and radial fracture zone are as 1.48～1.84,2.54～4.70 and 21.60～23.44 times as charge radius respectively. This holds identical views with that of traditional ideas.