下穿隧道掘进爆破振动传播规律研究

The Propagation Law of Vibration Wave on the Ground under Blasting in Tunnel Driving

为解决新建隧道近接下穿既有村庄爆破施工的安全难题,结合崇礼隧道下穿和平村建设项目,运用现场监测和信号分析的手段,研究爆破振动波在径向、切向和竖直向分别传播至地表的衰减规律。结果显示:爆破振动波传播规律受地质条件和测试方位的影响较大,三个方向的振动信号分别用萨道夫斯基公式进行回归分析,拟合效果良好,其中竖直方向振动信号拟合出的场地系数k值偏大,衰减系数α值偏小;利用FFT分析三向爆破振动信号频率分布广泛,主要集中在20~300Hz之间,无需考虑与地面建筑物共振情况;爆破振动信号传播至地表能量在垂直方向的低频部分比较集中,综合考虑峰值振速、频率、能量因素,竖直方向是爆破振动监测工作关注的重点。

In order to solve the safety problem of the blasting construction of the newly-built tunnel underneath the existing village,combined with the Chongli Tunnel underneath the Heping Village construction project,the method of on-site monitoring and signal analysis is used to study the radial,tangential and vertical vibration waves of blasting.The law of attenuation that propagates to the surface in a straight direction.The results show that the propagation law of blasting vibration is greatly affected by the geological conditions and the test orientation.The vibration signals in the three directions are respectively used for regression analysis with the Sadolfsky formula,and the fitting effect is good.Among them,the vibration signal in the vertical direction is fitted.The site coefficient k value is too large,and theαvalue is too small;using FFT to analyze the three-way blasting vibration signal has a wide frequency distribution,mainly concentrated between 20 and 300 Hz,without considering the resonance with the ground building;the energy of the blasting vibration signal propagating to the surface of the low-frequency part in the vertical direction is relatively concentrated.Considering the peak vibration speed,frequency,and energy factors,the vertical direction is the focus of blasting vibration monitoring.