310 mm孔径微差爆破降振研究

为有效降低310 mm孔径爆破对边坡的振动损伤，开展微差爆破降振研究。运用数值软件构建逐孔起爆模型，开展不同延期工况的爆破模拟，对应力波传播、应力峰值和应力时间作用强度等特征进行分析。研究结果表明，对于台阶底部，同时增大或减小孔排间延期，应力时间作用增强；对于台阶中部和上部，减小孔间延期，应力时间作用减弱，而增大孔间延期且减小排间延期，应力时间作用增强；对于台阶后方，增大排间延期或减小孔间延期，应力时间作用减弱。基于数值模拟分析，现场试验时将最后一排的排间延期增大20 ms。通过最小二乘法对试验前后爆破测振数据回归分析，对比可知，延期优化后距爆区后方10 m处的振动峰值下降39%，后方20 m处的振动峰值下降22%，反映出了显著的减振效果。

Research on Vibration Reduction of 310 mm Aperture Millisecond Blasting

In order to effectively reduce the vibration damage of slopes caused by 310 mm aperture blasting, the research on vibration reduction by millisecond blasting was carried out. Numerical software is used to establish hole by hole blasting model, carry out blast?ing simulation under different delay conditions, and analyze the characteristics of stress wave propagation, stress peak value and stress time effect. The research results indicate that for the bottom of the step, increasing or decreasing the delay between hole rows simultaneously enhances the stress time effect. For the middle and upper parts of the steps, reducing the inter hole delay weakens the stress time effect, while increasing the inter hole delay and reducing the inter row delay enhances the stress time effect. For the rear of the steps, increasing the delay between rows or decreasing the delay between holes weakens the stress time effect. Based on numerical simulation analysis, the delay between the last row was increased by 20 ms during on-site testing. Through regression analysis of blasting vibration measurement data before and after the experiment using the least squares method, the comparison shows that the vibration peak at a distance of 10 meters behind the blasting zone after delay optimization decreases by 39%, while the vibration peak at a distance of 20 meters behind the blasting zone decreases by 22%, reflecting a significant vibration reduction effect.