关林子隧道下穿既有道路爆破振动影响

在下穿既有道路的新建隧道爆破施工中,爆破振动极易引起上部路面结构的损伤和破坏.以宝汉高速新建下穿316国道的关林子隧道为例,采用有限元法模拟路面关键点峰值振速、路面应力以及路面位移,并结合现场爆破振动与振速监测结果,对比分析爆破振动对既有道路的影响.主要研究结论如下:10个关键点爆破峰值振速均发生在掏槽眼爆破时,既有道路的应力以及路面位移均较小,不足以引起既有道路的破坏;根据数值模拟和现场测试结果,下穿段地表质点振速的合速度峰值不超过0.035 m/s时可保证既有道路安全.

Influence of blasting vibration of Guanlinzi tunnel on the existing down-traversing road

In blasting construction of a new tunneldowntraversing the existing road, vibrations produced by the blasting are very easy to cause damage to upper pavement structure or even failure of the structure. Taking the new Guanlinzi Tunnel of Bao-Han Highway as an example, the finite element method is used to simulate the peak vibration velocity, pavement stress and pavement displacement of ten key points of the pavement. Combined with monitoring results taking from on-site blasting vibration and vibration velocity, the influence of blasting vibration on the existing road is compared and analyzed in this paper. The main research conclusions are as follows:the peak blasting velocity of the ten key points occurs during cut blasting. Both the road surface stress and the road surface displacement of the existing road are small, which is not enough to cause damage of the existing road.According to results of our numerical simulation and field tests, the existing road safety can be ensured when the peak value of combined velocity caused by vibrations on upper pavement surface of the underpass is less than 0.035 m/s.