隧道洞中爆破振动对地表影响的数值分析

Numerical Analysis of the Effect of Blasting In Tunnel on the Vibration of the Ground Surface

随着山区高速公路隧道的建设的发展,新建隧道洞中爆破施工引起地表振动已经日益成为急需解决的工程问题。针对隧道洞中爆破振动对地表影响的安全问题,结合花溪至安顺高速第五合同段跳花坡隧道爆破的工程概况,采用Midas/GTS有限元分析软件,建立了隧道洞中爆破振动对地表影响模型。基于此模型各振速的计算结果,分析了此模型不同时段各振速的变化规律,拟合出了地表各测点峰值总振速的预测公式。研究结果表明,随着爆破荷载作用时刻的增加,模型的总振速、水平振速、轴向振速和竖向振速都先增大后衰减。同时,多峰高斯函数可以用来拟合地表测点振速与高程差和爆心距离比值的公式。

With the development of tunnel construction of the expressway in mountains areas,the vibration of the ground surface caused by the blasting construction in the tunnel has been increasingly an engineering concern that to be addressed urgently.Focused on the safety issues of the impact of the blasting in the tunnel on the vibration at the ground surface,along with the subsurface conditions at the Tiaohuapo Tunnel of the Fifth Contract Section of the Huaxi-Anshun Expressway,the numerical model is established by using the commercial finite element analysis software MIDAS/GTS NX.The ground vibration velocities are obtained at various conditions.The results indicate that,with the increase of the blasting action time,the resultant total particle vibration velocity,horizontal as well as vertical variation velocities demonstrate an increase before the degradation.The multi point Gaussian function can be used to fit the relationship between the peak vibration velocity and the distance to the center of the blasting.