This study aims to clarify and gain an insight into the lateral dynamic response of offshore wind turbines (OWTs) supported by cement-soil composite steel (CCS) pipe pile embedded in gassy marine sediment layer by developing an analytical approach. In the proposed approach, the CCS pipe pile-supported OWT system is divided into three parts including the tower part, the seawater-immersed steel pipe pile part, and the embedded CCS pipe pile part. The lateral dynamic behaviours of the CCS pipe pile-supported OWT system have been determined and then validated by solving the analytical solution of lateral displacement for the above three parts. Numerical discussions are finally conducted to analysis the influence of some physical parameters on the lateral displacement and the first-order natural frequency of the CCS pipe pile-supported OWT system. The main findings can be summarized as: (i) the offshore deep cement-soil mixing (ODCM) pile is an effective reinforcement method to reduce the lateral vibration of conventional steel pipe pile-supported OWTs; (ii) the increase in tower height and seawater layer thickness will have a serious negative impact on the lateral dynamic response of CCS pipe pile-supported OWTs; (iii) the increase in gas saturation of gassy marine soil will lead to a negative influence on the maximum lateral displacement of CCS pipe pile-supported OWTs.

中文翻译：

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含气海洋沉积层水泥土复合钢管桩支撑海上风机横向动力响应分析方法


本研究旨在通过开发一种分析方法，阐明并深入了解嵌入含气海洋沉积物层中的水泥土复合钢（CCS）管桩支撑的海上风力涡轮机（OWT）的横向动态响应。在该方法中，CCS管桩支撑的OWT系统分为三个部分，包括塔架部分、海水浸没钢管桩部分和嵌入式CCS管桩部分。通过求解上述三个部分的横向位移解析解，确定并验证了 CCS 管桩支撑 OWT 系统的横向动力行为。最后进行数值讨论，分析了一些物理参数对CCS管桩支撑OWT系统横向位移和一阶固有频率的影响。主要发现可概括为：（i）海上深层水泥土搅拌桩（ODCM）是减少传统钢管桩支撑OWT横向振动的有效加固方法； (ii) 塔高和海水层厚度的增加将对CCS管桩支撑OWT的横向动力响应产生严重的负面影响； (iii)含气海相土壤含气饱和度的增加将对CCS管桩支撑的OWT最大横向位移产生负面影响。