基于声波逆时偏移成像的海上风电基础冲刷坑监测方法

METHOD OF SCOURING PIT MONITORING FOR OFFSHORE WIND POWER FOUNDATION BASED ON ACOUSTIC REVERSE TIME MIGRATION IMAGING

海上风电基础冲刷是目前海上风电基础面临的普遍问题,冲刷坑的探测与监测对保障桩基安全十分重要。针对现有探测方法存在成本高、无法准确描述冲刷坑发展和形态等缺陷,提出一种基于声波逆时偏移的监测方法,首先采用有限差分方法求解声波方程模拟在海上风电桩基上布置震源的声波传播过程,分析冲刷坑界面反射波的波场特征;在此基础上,提出一种线性观测系统用于监测冲刷坑发展过程,并提出基于逆时偏移的冲刷坑表面成像方法,通过多组数值模拟试验验证该方法对不同规模和形态的冲刷坑都有良好的成像效果,最大冲刷深度误差均在10%以内。最后采用沙坑模型试验进一步证明提出冲刷坑监测方法的有效性。

Our country has a vast sea area,long coastline,and abundant offshore wind energy resources,giving offshore wind power broad development prospects and making it crucial for energy transition.However,in complex marine environments,pile foundations alter the flow field,causing local scour and affecting structural safety and stability.Although there are many methods to monitor underwater structure scour,they have limitations in complex marine environments,making real-time monitoring challenging.In this article,a forward method for monitoring scour holes in offshore wind turbine foundations was established based on acoustic equations,and the wave field characteristics of the scour hole model were analyzed.On this basis,a linear observation system was proposed for monitoring the development process of the scour hole.The inverse time migration imaging method was used to achieve surface interface imaging of the scour hole.The numerical simulation results indicate that this method has good imaging effect for scour holes of different scales and shapes.