波浪作用下海上风电桩基冲刷复合防护方法试验

Test on Composite Protection Methods Against Offshore Wind Power Monopile Foundation Scour due to Waves

为探究海上风电基础有效的冲刷防护方法,针对某实际工程在波浪作用下的冲刷防护,分别提出抛石与柔性幕布、仿生水草与抛石、水平隔板与套筒等3种复合防护方法,并在波浪水槽中开展冲刷物理模型试验,分析不同防护手段作用下桩基周围的冲刷形态和最大冲刷深度。结果表明:柔性幕布可减小抛石单独作用时下潜流和马蹄涡对床身的剪切作用并减少床身砂石的流失;仿生水草可起到类似的作用,同时可减小正向流速和防止二次冲刷的作用;套筒可弥补水平隔板单独作用时水平隔板边缘易受冲刷的缺点。3种防护方法在波浪作用条件下的冲刷防护效果均较好,且水平隔板与套筒的复合防护方法效果最佳。

In order to investigate the effective protection methods against offshore wind power monopile foundation scour,three composite protection methods,namely riprap with flexible curtain,biomimetic aquatic grass with riprap and horizontal baffle with sleeve,are proposed to protect against scour under wave action in a specific engineering project.The physical model tests are carried out in a wave flume to analyze the scour morphology and maximal scour depth around the pile foundation under different protection methods.The results show that:the flexible curtain can reduce the shear effect of the submerging currents and horseshoe vortices on the seabed and reduce the loss of sediment;the biomimetic aquatic grass can provide similar effects while also reducing the forward flow velocity and preventing secondary scouring;the sleeve can compensate for the vulnerability of the edges of horizontal baffle to scouring when used alone.All three protection methods show good performance in mitigating scour under wave conditions,with the combined protection of horizontal baffle and sleeve being the most effective.