冲击载荷作用下炮孔近区节理岩体的动力响应

Dynamic Response of Jointed Rock near Blast Hole Under Impact Load

为研究钻孔爆破冲击载荷在岩体节理面的传播机制,设定了两种不同节理形式的模型,并对节理面的应力分布、振动速度、位移分布进行了数值研究。研究结果表明,节理面厚度固定不变时,随着炮孔距节理面空间距离的增加,节理面动态响应明显减弱,而在空间距离固定的情况下,随节理面厚度的增加同样对该面的动力响应存在削弱效应。另外,节理面倾角小于45°时,随倾角增大,应力和振动合速度峰值逐步减弱,而倾角大于45°时,应力和振动合速度峰值又逐渐增强。且以45°倾角为界限,小于45°时应力峰值衰减率逐渐减小,大于45°时应力峰值衰减率逐渐增大,但振动合速度峰值衰减率却一直增大,尤其在倾角大于45°以后,增大程度明显变强。

In order to study the propagation mechanism of borehole blasting impact load on the joint surface of rock,two models with different joint forms were set up,and the stress distribution,vibration velocity and displacement distribution at the joint surface were studied.The results show that when the thickness of the joint surface is fixed,the dynamic response of the joint surface is obviously weakened with the increase of the spatial distance between the blasthole and the joint surface.In the case of fixed spatial distance,the dynamic response of the joint surface is also weakened with the increase of the thickness of the joint surface.In addition,when the dip angle of the joint surface is less than 45°,the peak values of stress and vibration velocity gradually decrease with the increase of the dip angle,while the peak values of stress and vibration velocity gradually increase when the dip angle is greater than 45°.Taking the 45°dip angle as the boundary,the attenuation rate of the peak stress decreases gradually when the dip angle is less than 45°,and increases gradually when the dip angle is greater than 45°.But the attenuation rate of the peak vibration velocity increases all the time,especially when the dip angle is greater than 45°,the degree of increase is obviously stronger.