地应力对混凝土材料中爆炸应力波传播影响规律研究

Study on Influence of In-situ Stress on Propagation of Explosion Stress Wave in Concrete

为研究山体、坝体等自然环境下不同地应力水平对爆炸应力波传播的影响,采用数值模拟技术对不同地应力条件下混凝土试件进行爆炸模拟试验。通过对混凝土试件边界处施加不同大小的应力,观察了在不同地应力下试件承受爆炸荷载后的破坏现象;通过改变模型单边地应力数值设置对照组,随后对不同模型施加相同爆炸荷载,得到了试件中各预设的4个测点的峰值应力及质点运动速度。借助试验中测点峰值应力与质点运动速度等爆炸波特征参数的变化,进而分析了不同地应力大小对爆炸应力波传播的影响。结果表明:地应力对爆炸应力波的影响主要表现为在高地应力水平下的“抑制传播”与低应力水平下的“促进传播”。爆炸过程中,爆炸应力波与地应力的叠加耦合增大了测点峰值应力强度,反之,高地应力抑制了介质颗粒的位移,从而降低了质点运动速度。研究从不同地应力水平对爆炸应力波的传播影响角度入手,创新性地分析了地应力对应力波的抑制作用,其结果可为深地下钻孔爆破过程中破坏区的预判,地下结构抗爆防护等方面提供一定的理论依据。

To study the influence of different geo-stress levels on the propagation of explosive stress waves in natural environment such as mountains and dams,numerical simulation technology was used to simulate the explosion of concrete specimens under different geo-stress conditions.First,by applying different stresses to the boundary of the concrete specimens,the failure of specimens subjected to explosive load were observed.And then,the peak stress and particle velocity of the four preset measuring points on the specimen were obtained by changing the unilateral ground stress value and keeping the same explosion load on different models.Finally,the influence of geo-stress on the propagation of explosion stress wave was analyzed on different characteristic parameters of explosion wave,such as the peak stress and particle velocity.The results show that the influence of geo-stress on explosion stress wave is mainly manifested as“restraining propagation”and“promoting propagation”under high and low stress level,respectively.During the explosion process,the superposition coupling of explosion stress wave and in-situ stress increases the peak stress intensity of the measuring point.On the contrary,the high ground stress inhibits the displacement of the medium particles,thereby reducing the particle velocity.The research starts from the influence of different ground stress levels on the propagation of explosive stress waves,and creatively analyzes the inhibition of ground stress on stress waves.