砂土中吸力式筒形基础冲刷数值模拟分析

A numerical analysis of scour of suction bucket foundation in sand

为研究吸力式筒形基础在砂土中单向流作用下的冲刷机理和影响因素,本文通过建立三维数值模型,利用流体体积法跟踪自由液面和嵌套网格技术手段,基于重正化群湍流模型和梅叶-彼德推移质输运公式对吸力筒基础的局部冲刷进行模拟计算。结果表明:当流速较低时,吸力筒局部冲刷经历快速冲刷-缓慢发展-冲刷平衡3个阶段;当单向流流速大于2 m/s时,局部冲刷深度出现波动变化,且流速越大,流速对于最大冲深的影响越剧烈;吸力筒露出床面的部分越多,冲刷程度越大,达到冲刷平衡也更快;吸力式三筒基础筒间距影响水流下游方向筒基础内外侧局部冲刷深度的发展。本文研究结果可为工程中的吸力筒基础的设计运行和维护提供参考。

To investigate the mechanism and influencing factors of sand scouring around the suction bucket foundation under the influence of unidirectional flow,we established a three-dimensional numerical simulation model based on the renormalized group k-ε model and Meyer-Peter Muller formula.The results show that when the current velocity is very low,the local scour process of the mono-bucket foundation experiences three stages:rapid erosion stage,slow erosion stage,and equilibrium stage.The local scour depth fluctuated when the unidirectional flow velocity exceeded 2 m/s.The greater the velocity,the more severe the velocity's influence on the maximum scour depth.The larger the area of the suction tube exposed from the surface of the bed,the greater the scouring degree and the faster the scouring balance is achieved.The distance between the suction tripod-buckets of the foundation cylinders affects the development of local scour depth inside and outside the cylinder foundation in the downstream direction of water flow.The results of this paper can provide a reference for the design,operation,and maintenance of the suction bucket foundation.