疏浚工程中常利用射流进行河道清淤和冲砂施工。为探究喷嘴间距对射流冲刷的影响,开展了一系列不同靶距、速度和间距的双喷嘴冲刷粗砂、中砂砂床试验,分析了冲刷坑形、冲坑深度和冲坑截面积的变化特性,得到了各工况下的最优喷嘴间距L_B和不利喷嘴间距L_N。结果表明,对于同一粒径砂床,改变靶距和速度冲刷时的L_B和L_N值变化较小,而与粗砂砂床相比,冲刷中砂砂床时的L_B和L_N值均有所增加。研究成果可供疏浚工程中射流系统设计作为参考。 Dredging projects often use jets for river dredging and sand construction. In order to explore the effect of nozzle spacing on jet scouring, a series of sandblasting and sand bed test with double nozzle flushing with different target distances, velocities and spacings was carried out. The variations of scouring pits, depth of scouring pits and sectional area of ​​scouring pits were analyzed Characteristics, get the optimal nozzle spacing L_B and unfavorable nozzle spacing L_N under each condition. The results show that the L_B and L_N values ​​change little when the target distance and speed are changed, but the L_B and L_N values ​​increase when the bed is eroded . The research results are available for dredging engineering jet system design as a reference.