海上单桩风力机因海流冲刷桩基附近会形成冲刷坑,进而降低桩基埋土深度,影响结构稳定性。为研究冲刷及风-浪-地震载荷对大型海上风力机动力学响应的影响,建立考虑土-构耦合效应的单桩支撑结构有限元模型,对风力机进行时域分析。结果表明：冲刷对风力机高阶模态影响更大；仅有风-浪载荷激励时,随冲刷深度增加,风力机塔架和桩基整个时程曲线不断上移,位移显著增加,塔架和桩基主要运动都发生在湍流风来流方向；在风-浪-震载荷联合激励下,塔架和桩基动力学响应有所差异,当冲刷深度较小时,风力机塔架位移逐渐增加,但随着冲刷深度增加,塔架位移反而逐渐减小,而桩基位移随冲刷深度增加一直减小；风力机受风-浪-震载荷作用下各冲刷深度塔架和桩基位移相较于风-浪载荷时都有所增加。

The offshore single pile wind turbine will form a scour pit near the pile foundation due to the current scour, which will reduce the buried depth of the pile foundation and affect the structural stability. In order to study the influence of scour and wind-wave-seismic load on the dynamic response of large offshore wind turbine, a finite element model of single pile support structure considering soil-structure coupling effect was established to analyze the wind turbine in time domain. The results show that the erosion has a greater impact on the high-order mode of the wind turbine. When only the wind-wave load is excited, with the increase of scour depth, the whole time history curve of wind turbine tower and pile foundation moves up continuously, and the displacement increases significantly. Under the combined excitation of wind-wave-seismic load, the dynamic response of tower and pile foundation is different. When the scour depth is small, the displacement of wind turbine tower increases gradually, but with the increase of scour depth, the displacement of tower decreases gradually, while the displacement of pile foundation decreases with the increase of scour depth. Under the action of wind-wave-seismic load, the displacement of tower and pile foundation in each scour depth of wind turbine increases compared with that under wind-wave load.

TK221

基金项目：国家自然科学基金（51976131，52006148，52106262）；上海市IV类高峰学科-能源科学与技术-上海非碳基能源转换与利用研究院建设项目资助。