近距离交叉隧洞爆破对既有隧道的振动影响

Vibration effects on existing tunnel induced by blasting of an adjacent cross tunnel

结合南山下隧洞下穿温福客运专线钱仓山隧道工程,实时监测近距离交叉隧洞爆破施工对既有隧道的振动影响。实测结果表明,(1)迎爆面位置影响既有隧道断面的爆破振动速度分布;震源距离测点大于30m时,距离是爆破振动的主要影响因素;震源距离测点小于30m时,主要影响因素则为装药量与距离。(2)岩体越坚硬完整,爆破振动波传播衰减越慢。采用导洞先行预留光面爆破、导洞爆破掏槽眼和周边眼及底板眼分开起爆、控制最大段装药量等措施,可有效地降低爆破振动影响,控制其对钱仓山隧道的影响,对类似工程有借鉴作用。

Based on the engineering that Nanshanxia Tunnel down-traversing Qiancangshan Tunnel of Wen-Fu Passenger Dedicated Line,the vibration effects on the existing tunnel caused by blasting of an adjacent cross tunnel have been monitored.The results of the tests show that： the position of blasting surface affects velocity distribution of the cross-section of existing tunnel;when the distance between vibration source and measuring points is more than 30 m,the main influence factor of vibration is distance;while it is less than 30 m,the main factors are the amount of dynamite and distance;the harder and more complete the rock is,the slower the attenuation of the propagation of blasting vibration wave is.Measures such as pilot tunnel blasting in advance of smooth blasting;pilot tunnel blasting that the initiation of cutting holes,periphery holes and bottom holes are separated;and controlling maximum explosive volume for single segment can weaken the impact of blasting vibration effectively and control the vibration effects on Qiancangshan Tunnel;it can be a reference for similar projects.