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

这项教师早期职业发展（Career）计划将促进对潮汐地基独特行为的理解，改善小学和高中阶段的科学和工程教育，同时促进岩土工程领域的多样性。本研究将探讨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抵抗来自振动涡轮叶片的高横向载荷以及垂直和水平循环载荷，从而使涡轮机能够有效地吸收和利用附着在海底的潮汐能。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学习模块、演示、动画和视频等教育产品，这些产品将在研究员教授的课程和K-12外展项目中实施。将为布克·t·华盛顿STEM学院的四年级学生和高中女生数学、工程和科学冒险（G.A.M.E.S）夏令营开设可再生能源课程。本课题的研究目的是通过1g试验台（透明土和高岭土）和离心试验，在联合循环荷载作用下，对潮汐水轮机吸力沉箱基础体系进行评价。本文主要研究波浪作用下垂直、水平和力矩载荷的循环特性，潮汐涡轮叶片的旋转以及潮落和涨潮作用下水平载荷方向的变化。虽然对于直径小于10m（长度/直径= 3-5）的吸式沉箱作为锚杆的研究较多，但对于长径比为1-3的中等软粘土中，吸式沉箱作为基础单元的研究较少。此外，独特的垂直循环和水平荷载的半日或日（12或24小时）潮汐循环在以往的吸力沉箱基础设计中没有考虑到。试验测试的重点是研究循环荷载作用下地基的性能、破坏模式、荷载-位移响应、屈服行为和累积位移。这项研究工作将产生：(i)高质量的实验室数据；（ii）荷载-位移曲线和（iii）失效包络图/相互作用图，这将允许继续研究潮汐能涡轮机作为可再生能源的利用。

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.