基于雷管实际延时范围的逐孔爆破振动合成计算与应用

计算多段微差起爆合成振速对城市隧道低振速爆破设计具有非常重要的意义,因普通雷管实际每段都有延时误差,这些误差对低振速指标下微差合成振动影响不能忽略,但各段延时范围将形成海量的多孔微差合成振动曲线导致难以计算。为解决这一问题,将现场单孔爆破曲线作为震源波形,利用傅里叶级数拟合曲线,根据实测各段雷管延时范围特点,采用多级循环嵌套的逻辑语言编写MATLAB计算程序,成功获取8段微差爆破全部可能的合成振动曲线;分析了同段延时误差、不同段之间延时误差对爆破合成振动的影响;以计算合成振动曲线和实测爆破振动曲线对比判定第二临空面形成时间;计算其形成前各段延时范围内所有可能振动曲线后,选择峰值振速不超标的最大药量为设计掏槽药量。在某隧道工程应用表明:第二临空面出现在60ms,在1.0kg设计药量下最大计算合成振速0.62cm/s,与现场实测值吻合较好。

Calculation and application of hole by hole blasting vibration superposition based on measured delay times of detonators

It's important to calculate the superposed vibration velocity of multi-segments' millisecond blasting for low vibration velocity control in urban tunnels, but each segments of non-electric detonators have delay errors which can't be ignore in vibration's millisecond superposition under a low vibration velocity criterion. If each waves initiated one by one in consider of delay ranges between segments, it will forms a huge number of probable superposed vibration velocity curves which will result in no way to find a solution. To solve this, single-hole blast curve is took as wave of blast source, Fourier series is used to fit the curve. According to the measured time delay ranges of each segments' detonators, logical language is used to write MATLAB routine such as multistage nested loops, it is succeeded to get the probable superposed vibration velocity curves of 8 segments' millisecond blasting. The influence of the delay errors on the blast vibration is analyzed from the same segment and the different segments. The second free surface creation time is determined by compare the computed superposed vibration curve with measured blasting vibration curve. All the probable vibration curves are superposed within the delay ranges of each segments before the surface's formation, the maximum charge is selected as the designed one whose maximum peak result is safe. The application in a tunnel project shows that the second free surface created at 60ms and the maximum superposed vibration velocity is 0.62 cm/s by 1.0 kg design charge, which is in good agreement with the measured results in the field.