Seabed structures and foundations related to deep-sea resource development: A review based on design and research

The deep-sea ground contains a huge amount of energy and mineral resources, for example, oil, gas, and minerals. Various infrastructures such as floating structures, seabed structures, and foundations have been developed to exploit these resources. The seabed structures and foundations can be mainly classified into three types: subsea production structures, offshore pipelines, and anchors. This study reviewed the development, installation, and operation of these infrastructures, including their structures, design, installation, marine environment loads, and applications. On this basis, the research gaps and further research directions were explored through this literature review. First, different floating structures were briefly analyzed and reviewed to introduce the design requirements of the seabed structures and foundations. Second, the subsea production structures, including subsea manifolds and their foundations, were reviewed and discussed. Third, the basic characteristics and design methods of deep-sea pipelines, including subsea pipelines and risers, were analyzed and reviewed. Finally, the installation and bearing capacity of deep-sea subsea anchors and seabed trench influence on the anchor were reviewed. Through the review, it was found that marine environment conditions are the key inputs for any offshore structure design. The fabrication, installation, and operation of infrastructures should carefully consider the marine loads and geological conditions. Different structures have their own mechanical problems. The fatigue and stability of pipelines mainly depend on the soil-structure interaction. Anchor selection should consider soil types and possible trench formation. These focuses and research gaps can provide a helpful guide on further research, installation, and operation of deep-sea structures and foundations.