I-Corps: Multiline Ring Anchor for Floating Offshore Structures

这个i-Corps项目的更广泛的影响/商业潜力是为海上风能和海浪发电、大规模水产养殖和海岸保护提供一种具有成本效益的锚，用于将浮动结构物阵列系泊到海底。锚地/系泊系统成本可能占这些类型项目的总资本成本的很大一部分，因此从该锚地获得的成本节约可能会提高整个项目的经济竞争力。多线环形锚(MRA)具有圆形对称性，允许在一个锚上安装多个系泊绳索，大大减少了浮动单元阵列中的锚数量。MRA是为高效率而设计的--相对于其尺寸而言，高承载能力--从而需要更少的钢材、更小和更少的运输容器以及更小的安装和装卸设备。MRA还设计用于抵抗水平和垂直系泊缆线载荷，后者对于深水开发中张紧的系泊系统是必不可少的。美国水域的海底土壤条件变化很大，因此需要一种可以在多种土壤类型中安装并发挥作用的多功能锚。该i-Corps项目基于与多线环形锚(MRA)开发相关的两个研究领域的合并。第一个涉及风和波浪建模，以量化施加在平台上的随机、随时间变化的载荷，这些载荷通过系泊绳索向下传输到锚上。这项研究考虑了不同的平台类型，同时考虑了悬链式和张拉式系泊系统。第二个研究领域涉及对锚杆在承受这种荷载时的岩土性能的调查。本研究的主要内容包括粘性土和砂性土中埋入的MRA的并行数值模拟和土工离心机试验。岩土工程研究的目的是量化MRA能够承受的最大系泊线载荷，并确认反复的载荷循环不会导致锚杆逐渐向上棘轮运动，这可能会有害地影响锚杆的性能。风/浪模型和岩土技术研究将提供超出本研究直接重点的见解和知识，并可适用于其他系泊系统和锚。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

The broader impact/commercial potential of this I-Corps project is to provide a cost-effective anchor for mooring arrays of floating structures to the seabed, with applications in offshore wind and wave power generation, large scale aquaculture, and coastal protection. Anchorage/mooring system costs can comprise a significant portion of the total capital cost for these types of projects, so cost savings derived from this anchor may improve the economic competitiveness of the overall project. The Multiline Ring Anchor (MRA) has a circular symmetry to permit multiple mooring line attachments to a single anchor, greatly reducing the number of anchors within an array of floating units. The MRA is designed for high efficiency - high load capacity relative to its size - thereby requiring decreased amounts of steel, smaller and fewer transport vessels, and smaller installation and handling equipment. The MRA is also designed to provide resistance to both horizontal and vertical mooring line loads, the latter being essential for taut mooring systems in deep-water developments. Seabed soil conditions are highly variable in U.S. waters, leading to a need for a versatile anchor that can be installed and function in a wide range of soil types.This I-Corps project is based on the merging of two research areas associated with the development of the Multiline Ring Anchor (MRA). The first involves wind and wave modeling to quantify the stochastic, time-varying loads placed on platforms that are transmitted through the mooring lines down to the anchor. This study considers different platform types and both catenary and taut mooring systems. The second research area involves investigation of the geotechnical performance of the anchor when subjected to such loading. This research thrust comprises parallel numerical simulations and geotechnical centrifuge tests of the MRA embedded in clay and sand soils. The geotechnical studies aim to quantify the maximum mooring line loads that the MRA is capable of resisting and to confirm that repeated load cycles will not induce gradual upward ratcheting movements of the anchor, which could deleteriously affect anchor performance. The wind/wave modeling and geotechnical studies will provide insights and knowledge extending beyond the direct focus of this study and can be applicable to other mooring systems and anchors.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.