Abstract

This study investigates the effect of combined operational and seismic loads on the dynamic fore-aft, and the side-side response of monopile supported OWT in liquefiable soil under operational and parked conditions. A two dimensional (2 D) coupled soil-pile-structure interaction model is formulated in OpenSees, where the monopile and tower are modeled as Euler-Bernoulli beam elements, the soil is modeled as a quadrilateral plane strain element with solid-fluid fully coupled material. The soil column and monopile are connected by p-y springs. The effect of various strong-motion parameters, such as peak frequency, peak base acceleration (PBA), sustained maximum acceleration (SMA), and arias intensity (I_A) on the dynamic response of the OWT structure is studied. Also, the effect of peak frequency on the dynamic response of the OWT structure is studied by varying the hub height and RNA mass so as to keep the fundamental frequency of the OWT structure closer to the peak frequency of the ground motion records. Finally, the implication in the performance-based seismic design is suggested.

摘要

本研究调查了组合操作和地震载荷对动态前后的影响，以及在操作和停放条件下可液化土壤中单桩支撑的 OWT 的侧向响应。在OpenSees 中建立了二维 (2D) 耦合的土 - 桩 - 结构相互作用模型，其中单桩和塔被建模为 Euler-Bernoulli 梁单元，土壤被建模为具有固流完全耦合的四边形平面应变单元材料。土柱和单桩由py弹簧连接。各种强运动参数的影响，例如峰值频率、峰值基础加速度 (PBA)、持续最大加速度 (SMA) 和咏叹调强度 ( I _A) 对 OWT 结构的动力响应进行了研究。此外，通过改变轮毂高度和 RNA 质量来研究峰值频率对 OWT 结构动态响应的影响，以保持 OWT 结构的基频更接近地震动记录的峰值频率。最后，提出了基于性能的抗震设计的启示。