珠海金湾海上风电单桩基础局部冲刷试验研究

Study on local scour of monopile foundation of Zhuhai Jinwan offshore wind farm

针对珠海金湾局部冲刷深度难以用现有经验公式进行预测的问题,本研究通过建立正态物理模型,研究风电场风机基础建设后的海床局部冲刷情况。研究结果表明:波流共同作用时的冲刷深度小于纯流作用时的,在该海况下波浪具有回填作用;冲刷坑主要围绕在桩基周围,最大冲刷深度出现在基础迎水面和两侧,背水面冲刷坑略浅,尾流区有淤积;冲刷达到稳定后,柱基前后冲坑坡度约为1:10~1:1,且桩前的冲刷坡度大于桩后的;受尾涡脱落的影响,桩基侧后方海床冲刷较明显,冲刷显著区与主流方向的夹角在30°~66°之间。

Aiming at the difficulty of predicting the local scour characteristics of Jinwan in Zhuhai by using existing empirical formula,a normal physical model was established in this study to study the local scour conditions after the fan infrastructure construction in Jinwan offshore wind farm. The results show that when the scour depth under the combined action of waves and currents is less than that under the action of pure currents,the wave shows the effect of backfill. The scour holes mainly occur around the pile foundation,and the maximum scour depth is found in the seaside and both sides of the monopile. The scour on the leeside is slightly shallow,and there is siltation in the wake area. The slope of scour hole is about 1:10~1:1 under the combined action of waves and currents after reaching stability of scour,and the slope before the pile is greater than that after the pile. The seabed erosion in the posterolateral side of pile foundation is more obvious under the influence of the trailing vortex shedding,the angle between the main scour zone and the flow direction is about 30° ~ 66°.