浅埋隧道爆破振动地表质点响应规律研究

Research on the Response Law of Surface Particle for Shallow Buried Tunnel Blasting Vibration

以某区间隧道平行侧穿砖混结构危楼为工程背景,采用TC4850测振仪现场实测129组爆破振动数据,对地表固定测点的爆破振动质点响应规律进行研究,将爆破振动速度沿垂直切向、水平切向与水平径向3个矢量方向进行分解,发现以下主要规律：单一炮次的最大振速出现在垂直方向的概率最大,出现在水平切向次之,出现在水平径向的概率最小,且出现在水平切向和水平径向的概率相差不大。说明在研究单一方向的爆破振动对地表建筑物的影响时,应优先选用垂直方向的振速作为分析对象。三矢量方向的主振频率无明显的变化规律,但整体随着爆心距的增加呈现减小的趋势,且减小的幅度较小。三矢量方向的主振频率主要集中在20~100 Hz之间,爆破地震波中的高频成分的衰减速度大于低频成分的衰减速度,基本上不会引起附近建筑产生结构共振现象。

A tunnel in parallel and crossing a dangerous building of brick and concrete being the engineering background,TC4850 vibrometer is used to measure 129 groups data of blasting vibration to study response law of particle vibration at blast for fixed points on ground,the blasting vibration velocity are divided along the vertical cutting direction,horizontal cut and horizontal radial three vector directions.It is found that：the vertical direction has the largest possibility to appear the maximum vibration velocity for a single gun times,and the second possibility appear at horizontal cutting direction,and the lowest is at the horizontal radial direction;and there is no big difference for horizontal cut and horizontal radial directions.It indicates that when studying the impact of single direction vibration on the ground buildings,the vertical direction of the vibration velocity should be selected as the analysis object.There is no obvious change in the main frequency of the three vector direction,but the overall increase of the burst center distance is decreased,and the amplitude is small.The main vibration frequency of the three vector direction is mainly concentrated in the 20～100 Hz,the attenuation of high frequency components in the blasting seismic wave is greater than that of the low frequency component.