密集建筑物下隧道开挖微振控制爆破方法与振动分析

A precisely-controlled blasting method and vibration analysis for tunnel excavation under dense buildings

为适应城市密集建筑物下隧道爆破对振动的高安全要求,研究用普通爆破器材进行振速精确控制的爆破技术和参数确定方法。以渝中隧道为研究背景,在开发准确延时非电雷管的基础上,利用傅立叶函数和MATLAB软件拟合了不同药量单孔爆破振动波形,分析了1~50ms不同间隔下振动叠加的量化数据;讨论了各微差间隔时间的降振效果;在指定振速的情况下,确定单孔药量和微差起爆时间;实测并分析了现场使用雷管各段微差间隔特点,据此进行针对性的爆破设计和采用逐孔掏槽爆破进行振速控制。现场应用表明：隧道爆破振速始终小于1.00cm/s,在此振速下避免振动叠加的最优单孔药量为1.2kg,爆破振速峰值位于主掏槽的第1段或第2段雷管起爆后,且与理论分析结果吻合较好;逐孔起爆60ms后振速下降50%以上。研究表明：在高安全指标下,以非电雷管实施精确控制爆破是可以实现的。

To meet higher security requirements for blasting vibration from urban tunnel excavation under dense buildings,a new blasting technology was proposed and the corresponding method for obtaining parameters was explored.The proposed blasting technology uses non-electric detonators to precisely control blasting vibration.Chongqing Yuzhong connecting tunnel was taken as the research background.By applying Fourier function and MATLAB software,the vibration velocity curves were fitted for single-hole blasting with different charges and the quantification data of vibration superposition at different millisecond intervals from 1to 50 ms were analyzed.The vibration-reduction effect was discussed for different millisecond intervals.The parameters about blasting charge and detonating time delayed were determined under given vibration velocities.Interval characteristics of each period between detonators in the field were measured and analyzed.Accordingly,the blasting scheme was designed,which using hole-by-hole cut blasting to control vibration.The blasting vibration velocity measured in the field is below 1.00cm/s,and the corresponding reasonable single-hole charge is1.2kg for avoiding vibration superposition.The vibration velocity peak occurs after the detonation of the first or second-period detonator in the main cut area,which is consistent with the theoretical results.And the vibration velocity decreases by more fifty percent after 60 ms of hole-by-hole blasting.So blasting vibration can be precisely controlled by using non-electric detonators under high safety standard.