Multiscale modelling of shelly carbonate sands for foundation design of offshore structures (MuMShell)

用于海上结构基础设计的贝状碳酸盐砂的多尺度建模 (MuMShell)

• 批准号: EP/N018168/1
• 负责人: Joana Fonseca
• 金额: $ 12.71万
• 依托单位: City, University of London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2016
• 资助国家: 英国
• 起止时间: 2016 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FN018168%2F1
• 关键词: Multiscale; modelling; shelly; carbonate; sands

Carbonate soils cover over 40% of the world's seabed, where offshore structures, pipelines, artificial islands and other marine structures are founded. For the most part, carbonate soils are of biogenic origin comprising skeleton bodies and shells of small organisms, the shelly carbonate sands. These soils are a complex and poorly understood material as evidenced by a number of accidents reported during platform installation in the 80s. As a consequence, shelly sands have been placed into a niche classification of "problematic soils" in most design guides. While failures are now relatively rare, conservative methods and high factors of safety are commonly used. Understanding the behaviour of shelly carbonate sand is critical for the design of foundations for offshore structures. In particular, understanding the physical phenomena taking place at the microscale has the potential to spur the development of robust computational methods to be integrated into novel or existing design approaches.Image-based geomechanics is a fascinating research field that has the potential to transform the way soils are investigated and modeled. The ability to follow deformation at the microscale has helped to answer fundamental questions about the soil behaviour observed at the macro-scale. The proposed research uses 4D synchrotron x-ray imaging and post analysis to investigate the kinematics and the strain maps of a shelly carbonate sand under compression. The outcomes will contribute scientific understanding on the multiscale behaviour of shelly carbonate sands. This will form the basis to develop fabric-informed constitutive models to better predict the soil response, thus improving design practices for foundations of offshore structures. The ambition of this project is to contribute towards safer, less conservative and more sustainable ground structures and reduce the financial risks associated with unforeseen ground response during construction of offshore foundations. This multiscale methodology and image algorithms here developed, will be valuable to the broad granular media community to simulate mechanical processes in additive manufacturing, mining, food and pharmaceutical industries.

碳酸盐土壤覆盖了世界上40%以上的海底，在那里建立了海上结构，管道，人工岛屿和其他海洋结构。碳酸盐土壤大部分是生物成因的，由小生物的骨架和外壳组成，即壳状碳酸盐砂。这些土壤是一种复杂且难以理解的材料，正如80年代平台安装期间报告的一些事故所证明的那样。因此，在大多数设计指南中，shelly砂被归入“有问题的土壤”一类。虽然现在故障相对较少，但通常使用保守方法和高安全系数。了解壳状碳酸盐砂的行为对海上结构的基础设计至关重要。特别是，理解在微观尺度上发生的物理现象有可能刺激强大的计算方法的发展，将其集成到新的或现有的设计方法中。基于图像的地质力学是一个迷人的研究领域，它有可能改变土壤研究和建模的方式。在微观尺度上跟踪变形的能力有助于回答在宏观尺度上观察到的土壤行为的基本问题。本研究采用四维同步x射线成像和后期分析技术研究了一种壳状碳酸盐砂在压缩下的运动学和应变图。这些结果将有助于科学地理解贝壳状碳酸盐岩砂的多尺度行为。这将为开发基于结构的本构模型奠定基础，从而更好地预测土壤反应，从而改进海上结构基础的设计实践。该项目的目标是为更安全、更保守、更可持续的地面结构做出贡献，并减少海上基础建设期间不可预见的地面反应带来的财务风险。这里开发的这种多尺度方法和图像算法，将对广泛的颗粒介质社区模拟增材制造、采矿、食品和制药行业的机械过程有价值。

项目成果

Image based simulation of one-dimensional compression tests on carbonate sand

• DOI: 10.1007/s11012-018-0923-2
• 发表时间: 2018-11
• 期刊: Meccanica
• 影响因子: 2.7
• 作者: S. Nadimi;J. Fonseca

Proceedings of the 1st Vietnam Symposium on Advances in Offshore Engineering. VSOE 2018. Lecture Notes in Civil Engineering

第一届越南海洋工程进展研讨会论文集。

• 发表时间: 2019
• 作者: Fonseca J

Proceedings of the 1st Vietnam Symposium on Advances in Offshore Engineering - Energy and Geotechnics

第一届越南海洋工程进展研讨会论文集 - 能源和岩土工程

• DOI: 10.1007/978-981-13-2306-5_5
• 发表时间: 2019
• 作者: Fonseca J

Quantification of the morphology of shelly carbonate sands using 3D images

• DOI: 10.1680/jgeot.16.p.278
• 发表时间: 2018-03-01
• 期刊: GEOTECHNIQUE
• 影响因子: 5.8
• 作者: Kong, D.;Fonseca, J.
• 通讯作者: Fonseca, J.

On the kinematics of shelly carbonate sand using X-ray micro tomography

• DOI: 10.1016/j.enggeo.2019.105268
• 发表时间: 2019-11-01
• 期刊: ENGINEERING GEOLOGY
• 影响因子: 7.4
• 作者: Kong, Deqiong;Fonseca, Joana
• 通讯作者: Fonseca, Joana