垂直淹没射流对黏性底床冲刷挖掘体积的试验研究

射流冲刷作为一种高效挖掘手段被广泛应用于深海工程领域。针对黏性底床条件下垂直淹没射流冲刷挖掘体积进行研究,利用注浆成型法制备冲刷坑的胚体并利用3 d扫描技术获取冲刷挖掘体积。通过开展室内试验探索了射流流速、射流靶距、冲刷时间以及泥样含水率与冲刷挖掘体积的关系:1)冲击射流挖掘体积随着射流靶距的增加而减小;2)冲击射流挖掘体积随着射流流速的增加而增加;3)冲击射流挖掘体积随着冲刷时间的增加而增加,但逐渐趋于平衡;4)随着泥样含水率的增加,冲击射流挖掘体积也显著增加。最后,利用54组试验数据和无量纲分析得到了冲击射流挖掘体积的经验公式,可为射流挖沟以及射流沉桩等海洋工程实践提供参考。

Experimental study on scour volume from a cohesive bed by vertically submerged water jet

As an efficient and convenient method,water jet scouring technology has been widely used in deep sea engineering.The scour volume from a cohesive bed under a vertical submerged jet scouring has been studied.The contour embryo of scour volume was obtained by grouting method,and the scour volume of was evaluated by 3D scanning technology.Through indoor test,the relationship among jet velocity,impingement height,scour time and water content of mud sample and scour volume are explored:1)Scour volume decreases with the increase of impingement height.2)Scour volume increases with the increase of jet velocity.3)Scour volume increases with the increase of scour time,but gradually tends to balance.4)With the increase of water content of mud sample,the scour volume increases significantly.Finally,based on 54 sets of experimental data and dimensionless analysis,an empirical formula of scour volume is obtained,which may provide a reference for water jet trenching and water jet assisting pile installation in ocean engineering.