NEESR-CR: Capacity and Performance of Foundations for Offshore Wind Towers

该奖项是NSF 09-524项目征集“小乔治·E·布朗地震工程模拟网络(NEES)研究(NEESR)”竞赛的结果，包括德克萨斯农工大学(牵头机构)、康涅狄格大学和普莱里维尤农工大学(子奖)。该项目将利用伦斯勒理工学院的NEES设备场地。在过去的几年里，人们的兴趣越来越集中在替代能源和可再生能源上。风能作为化石燃料的替代品正受到密切关注，而风力发电的发电量一直在迅速增加。在美国和国际上的许多地方，陆上风力发电场的建设引发了环境和美学方面的担忧。此外，陆地风循环和每日能源使用周期不是很匹配，峰值风出现在能源需求最低的时候，这就需要开发储能策略和装置。另一方面，海上风电场的开发可以避免大多数美学问题，还可以获得更低高度的更强和持续的风，以及更一致的风和使用周期。这项建议的目的是评估最有效的海上风塔基础系统，通过检查不同系统的性能，当结构在风和波浪荷载作用下。智力优势该项目将在NEES@Rensselaer设施进行离心机测试。测试计划将重点放在单体桩和吸力沉箱上。初步测试将在德克萨斯农工大学的试验台上进行，以评估工具和模型以及传感器的设计。该测试将用于表征基础系统在类似于海上风塔将受到的载荷条件的全面范围内的响应。采用数值分析的方法，用真实的土体模型模拟塔基-地基-土体系的反应。数值模型和土壤模型将根据测试进行验证。更广泛的影响目前用于海上风塔的基础可能不是这种应用的最有效的解决方案，特别是在较弱的土壤中。近海石油和天然气行业发展起来的基础设计并不适用于近海风塔基础，设计规范也没有为设计者提供足够的指导。由于基金会占海上风塔成本的很大一部分，选择最有效、最经济的系统将提高海上风能发电的可行性。来自草原景观农工大学的本科生将在整个项目中与他们的校园、塔马大学和康涅狄格州大学的研究人员合作。通过暑期REU体验，将促进更多的本科生参与。将通过示范和教师参与研究活动，面向K-12学生开展外联工作。教育和外联计划通过促进实践活动、增加互动以及研究和教育的整合来解决多样性问题，这些活动有效地改善了工程学中任职人数不足的群体的留住情况。该项目的数据将被存档，并通过NEES数据库向公众提供。该奖项是国家减少地震灾害计划(NEHRP)的一部分。

This award is an outcome of the NSF 09-524 program solicitation "George E. Brown, Jr. Network for Earthquake Engineering Simulation (NEES) Research (NEESR)" competition and includes Texas A&M University (lead institution), the University of Connecticut and Prairie View A&M University (subawards). This project will utilize the NEES equipment site at Rensselaer Polytechnic Institute.In the last few years, interest has been increasingly focused on alternative and renewable sources of energy. Wind energy as an alternative to fossil fuels is receiving close attention while the number megawatts produced has been rapidly increasing. In many locations in the United States and internationally, construction of onshore wind farms has raised environmental and aesthetic concerns. In addition, the terrestrial wind cycle and the daily energy use cycle are not well matched, with peak winds occurring when the energy demand is at its lowest, requiring the development of energy storage strategies and devices. On the other hand, offshore wind farm development can avoid most of the aesthetic issues, with the added benefit of stronger and sustained winds at lower heights and more aligned wind and usage cycles. The goal of this proposal is to evaluate the most effective foundation system for offshore wind towers by examining the performance of different systems when the structure is subjected to both wind and wave loading. Intellectual meritThe project will carry out centrifuge testing in the NEES@Rensselaer facility. The testing program will focus on monopiles and suction caissons. Preliminary testing will be conducted using testbeds at Texas A&M University to evaluate the design of the tools and the models, as well as the sensors. The testing will be used to characterize the response of the foundations systems under a comprehensive range of loading conditions similar to those an offshore wind tower would be subjected to. Numerical analysis will be used to simulate the response of the tower-foundation-soil system with realistic soil models. The numerical and soil models will be validated against the testing. Broader impact The foundations currently used for offshore wind towers may not be the most effective solution for this application, especially in weaker soils. Foundation designs which evolved in the offshore oil and gas industry are not readily applicable to wind tower foundations offshore and design codes are not providing sufficient guidance for designers. Since foundations account for a significant part of the cost of offshore wind towers, choosing the most effective and most economical system will improve the viability of offshore wind energy generation.Undergraduate students from Prairie View A&M University, a Historically Black University, will work with the researchers at their campus, TAMU and UConn throughout the project. Additional undergraduate involvement will be promoted through summer REU experiences. Outreach efforts will be directed towards K-12 students, through demonstrations and teacher involvement in the research activities. The educational and outreach plan addresses diversity by promoting hand-on activities, increased interaction and integration of research and education, which have been effective in improving the retention of underrepresented groups in engineering. Data from this project will be archived and made available to the public through the NEES data repository. This award is part of the National Earthquake Hazards Reduction Program (NEHRP).