桩基承台结构的波流力研究进展

Recent Progress in Wave-Current Loads on Foundation Structure With Piles and Cap

我国近海风电场建设大多采用桩基承台结构.总结了不规则波浪和水流共同作用下桩基承台结构的波流力物理模型实验结果,得到了群桩效应系数及其变化规律,讨论了作用于近水面承台底部的波浪拍击力;从理论上分析了规则波作用下承台对桩基波浪力的影响;建立了规则波与桩基承台相互作用的数值模型,揭示了波浪在承台的上浪与爬高及其水动力特征.鉴于桩基承台结构包含多个斜桩和较大尺度的承台,在波浪与水流作用下该结构物附近的流场结构十分复杂,有必要针对结构附近的流动结构以及自由表面大变形开展细致的实验和数值模拟研究,以进一步揭示作用于这类结构的波流力变化规律及其机理.

The foundation structure with piles and cap is one of the widely used structures for offshore wind farm construction in shallow water. The experimental studies on hydrodynamic loads acting on the piles and cap under irregular waves and currents were summarized with dis- cussion about the pile group effect on wave forces and wave impact loads upon the cap locating near the free surface. Through theoretical solution of the wave diffracted by the cap and appli- cation of the Morison equation to evaluate the wave force on piles, the effects of the cap on wave force upon piles were investigated. Based on the RANS equations and the VOF method, a numerical wave basin was developed to simulate the wave-structure interaction. The computed maximum wave force on the foundation structure with piles and cap agreed well with the meas- ured data. The violent deformation, brealdng and runup of wave around the structure were pro- vided and discussed. Further work on the turbulent flow structures and large deformation of the free surface due to interaction of waves and foundation structures of offshore wind farms is needed to develop efficient approaches for evaluating hydrodynamic loads under the waves and currents.