不同间距邻近爆破载荷下隧道破坏规律及动态响应研究

Research on Failure Rule and Dynamic Response of Tunnel Under Adjacent Blasting Loads of Different Spacing

试验研究和数值分析是研究不同间距邻近爆破载荷下隧道动态破坏问题的有效手段.通过试验研究发现,当间距较小时,迎爆侧呈三角形破坏,背爆侧表现为起拱点和底角的裂纹扩展,且随间距增加,破坏程度逐渐减弱.通过LS-DYNA数值模拟研究发现,当炸药量一定时,随间距的增加,起拱点位置振速峰值呈指数型衰减,当间距小于3D时,衰减较快,且振速峰值大于安全振速,位于危险间距内;当大于3D时,衰减缓慢,位于安全间距内.迎爆侧振速峰值最大区域分布在直墙中部至起拱点位置,直墙中下部和拱形部位次之.

Experimental research and numerical analysis are effective methods for researching failure rule and dynamic response of tunnel under adjacent blasting loads of different spacing.Through experimental research,the following results were found.When spacing was smaller,the side facing blasting showed triangle-shaped damage.The back side of blasting side showed crack growth of sprung arch and base angle with the increase of spacing,the failure degree became lower.The research was conducted using the software LS-DYNA.When explosive mass remained the same,the vibration velocity of sprung arch decreased by exponential function with the increase of spacing.When the spacing was less than 3 D,the peak velocity of attenuation was faster and the peak value of vibration velocity was larger than safe vibration velocity,which was very dangerous.When the spacing was larger than 3 D,the peak velocity of attenuation was slower and the spacing was safe.The largest region of vibration velocity peak value was located in the range from the middle part to sprung arch,and then the bottom of stalk and arch.