淹没条件下超高压水射流冲蚀切割破岩实验研究

运用超高压射流数控自动万能切割机进行了淹没条件下水射流冲蚀切割破岩实验，选取了5档驱动压力和3种岩样，研究了水射流驱动压力、喷距、喷嘴横移速度和喷射角对破岩效果的影响。实验表明，淹没条件下超高压水射流冲蚀切割破岩存在最优喷距，最优喷距随压力的增加而增加；100 MPa时最优喷距约为15倍喷嘴直径，200 MPa时约为20倍喷嘴直径；喷嘴移动速度越小，冲蚀体积越大，随着移动速度的增加，开始时冲蚀体积下降明显，但移动速度进一步增加时，冲蚀体积减小并不明显,岩石的主要破坏发生在毫秒量级；最优冲蚀破岩效果的喷射角范围为12°~14°。

Experiment on Rock Breakdown by Super-High-Pressure Water Jet in Submerged Environment

This article studies the effects of jet distance, nozzle movement speed, and jet angel on formation breakdown. Experiments on rock breakdown by submerged superhigh pressure water jet  have been conducted using a digital controlled superhigh pressure jet cutting machine under 5 pressures with 3 rock samples. The experiments show there exists an optimum jet distance, which increases with the jet pressure. It is 15 times the nozzle diameter when pressure is 10 MPa, and about 20 times the nozzle diameter at 200 MPa. And it is found the slower the nozzle moves, the larger the breakdown volume, the breakdown volume will decrease dramatically at first when the move speed increases, but it will not decrease so obviously later when further increasing move speeds. The rock breakdown occurs within mili seconds. It is also found an optimum rock breakdown efficiency can be achieved when the jet angle ranges between 12°~14°.