楔形分段掏槽爆破减振效应研究
Vibration Reduction Effect of Stepped V-Cut Blasting

为研究隧道楔形分段掏槽爆破方法的减振效率，基于岩体微差破岩理论，推导楔形分段掏槽爆破参数的确定方法，并运用LS-DYNA3D程序对楔形常规掏槽爆破和楔形分段掏槽爆破时爆破近区应力波传播过程及质点振动速度进行仿真计算分析，结合数值模拟结果和工程实际情况，开展楔形常规掏槽爆破和楔形分段掏槽爆破现场对比试验，结果表明：楔形分段掏槽爆破中炮孔底部有效应力峰值和压缩破坏深度分别约为楔形常规掏槽爆破的1.64倍和1.66倍，槽腔更易达到设计深度；模型中岩体顶面和背面平均减振效率分别达到11.53%和22.45%，但侧面平均减振率仅0.21%；楔形分段掏槽爆破方法可将掏槽爆破振动强度降低30%以上，且施工效率略有提高.
：The aim of this research is to study the vibration reduction effect of stepped V-cut blasting (SV-cut) in tunnel blasting. Firstly, the method for determining SV-cut blasting parameters are provided based on the rock millisecond blasting theory. Secondly, numerical computation models for both traditional vertical V-cut blasting (V-cut) and SV-cut blasting are established using the explicit dynamic finite element program LS-DYNA3D. Finally, combined with numerical simulation results and engineering practice, in-situ contrast blasting experiments and vibration tests using both V-cut and SV-cut blasting were performed. The results of the study indicate that the peak Von Mises stress and compression damage range at the bottom of the cut cavity for SV-cut blasting are 1.64 times and 1.66 times larger than that for V-cut blasting, respectively, which results in a more complete cut cavity with SV-cut blasting. At the top and back side of the model, the vibration reduction effectiveness of SV-cut blasting is up to 11.53% and 22.45%, respectively; however, the vibration reduction effectiveness is only 0.21% at the lateral side. SV-cut blasting can not only enable perfect blasting drivage but can also reduce the vibration intensity induced by cut hole blasting by at least 30%