CAREER: Experimental Modeling of Tidal Current Turbine Foundations: An Integrated Research and Education Plan

这项学院早期职业发展(CALEAR)计划补助金将促进对潮流基金会独特行为的了解，并改善小学和高中水平的科学和工程教育，同时促进岩土工程领域的多样性。这项研究将研究高效可靠的海底潮流涡轮机基础系统。基础的设计必须能够承受高横向载荷以及来自振动涡轮叶片的垂直和水平循环载荷，从而使涡轮机在连接到海底时能够有效地吸收和利用潮汐能量。降低基础系统的成本是使潮汐能成为一种可行和经济的电力来源的重要组成部分。研究任务将用于制作教育产品，如学习模块、演示、动画和视频，这些产品将在研究人员教授的课程和K-12推广方案中实施。布克·T·华盛顿STEM学院的四年级学生和高中女生的数学、工程和科学冒险(G.A.M.E.S)夏令营将开设一堂可再生能源课程。该项目的研究目标是通过使用1G标准(在透明土壤和高岭土中)和离心机测试在复合循环荷载下的基础性能来评估潮流涡轮机的吸力沉箱基础系统。重点研究了波浪作用下的垂直载荷、水平载荷和力矩载荷的周期性，潮流水轮机叶片的旋转以及落潮和涨潮引起的水平载荷方向的变化。在直径小于10m(长径=3~5)的软土中，采用负压沉箱作为锚杆的研究已有很多，但在L/D=1~3的中等高宽比的软土中，采用负压沉箱作为基础单元的研究还很少。此外，在以往的吸力沉箱基础设计中，还没有考虑到水平荷载的独特的垂直循环和半日或昼夜(12或24小时)的潮汐循环。试验测试的重点是研究循环荷载作用下的地基性能、破坏模式、荷载-位移响应、屈服行为和累积位移。研究工作将产生：(I)高质量的实验室数据；(Ii)载荷-位移曲线；(Iii)故障包络/相互作用图，这将使继续研究利用潮流涡轮机作为可再生能源的问题。

This Faculty Early Career Development (CAREER) Program grant will advance the understanding of the unique behavior of tidal current foundations and improve science and engineering education at the elementary and high school levels, while promoting increased diversity in the field of geotechnical engineering. The research will investigate efficient and reliable foundation systems for undersea tidal current turbines. The foundations must be designed to resist high lateral loads as well as vertical and horizontal cyclic loading from the oscillating turbine blades, allowing the turbines to effectively absorb and harness the tidal energy while attached to the seafloor. Decreasing the cost of the foundation system can be an important part of making tidal power a viable and economical source of electricity. The research tasks will be used to produce educational products such as learning modules, demonstrations, animations and videos that will be implemented in the courses taught by the researcher and in K-12 outreach programs. A renewable energy lesson will be created for the 4th grade students at Booker T. Washington STEM Academy and the Girls Adventures in Mathematics, Engineering, and Science (G.A.M.E.S) camp for high school girls.The research objective of this project is to evaluate suction caisson foundation systems for tidal current turbines by examining the foundation performance using both 1g bench-scale (in transparent soil and Kaolin) and centrifuge testing under combined cyclic loading. This research focuses on the cyclic nature of the vertical, horizontal and moment loading due to waves, the rotation of the tidal current turbine blades and the change in direction of the horizontal loading due to ebb and flow tides. Although there have been many studies on the use of suction caissons as anchors with diameters less than 10m (Length/Diameter = 3-5), few researchers have investigated using suction caissons as foundation elements in soft clays with intermediate aspect ratios of L/D = 1-3. In addition, the unique vertical cycling and semidiurnal or diurnal (12 or 24 hr) tidal cycling of the horizontal load has not been accounted for in previous designs of suction caisson foundations. The focus of the experimental testing is to investigate the foundation performance, failure modes, load-displacement response, yielding behavior, and cumulative displacements under cyclic loading. The research effort will result in: (i) high quality laboratory data; (ii) load-displacement curves, and (iii) failure envelopes/interactions diagrams, that will allow for the continued study of the utilization of tidal current turbines as a renewable energy source.