• Provide a brief introduction about seabed structures and foundations related to deep‐sea resource development. • Introduce subsea production structures, including subsea manifolds and their foundations (mudmats, suction piles), from a design perspective. • Analyze the basic characteristics and design methods of deep‐sea pipelines, including subsea pipelines and risers. • Introduce the installation and bearing capacity of anchors in deep‐sea, and summarize seabed trench influence on anchor capacity.
• The latest research results of the interaction between internal solitary waves (ISWs) and the seafloor are introduced, and the unresolved problems in the current research work are summarized. • ISW generates forces and shear on the seafloor and thus affects sediment suspension in the deep bottom boundary layer. • This study provides a new perspective for an in-depth understanding of the interaction between ISW and the seafloor.
• Offshore limemud is a storehouse of carbonate minerals. • Studies on their industrial applications have not been done earlier. • This paper provides information on the huge resource of high-grade limemud in the Indian offshore and their suitability for various industrial applications.
• The response of hydrate reservoirs with various angle slopes to gas production is predicted. • Low permeability would limit the long-term gas recovery rates of clayey reservoirs. • Reservoirs without slope angle show the highest gas production and seabed settlement. • There is a risk of potential damage of the production wellbore during long-term gas production.
• Based on the renormalized group κ-ϵ turbulence model and Stokes fifthorder wave theory, a three-dimensional numerical model of currents and waves–submarine pipeline–silty sandy seabed was established for scouring. • The reliability and accuracy of the numerical model were verified against experimental data measured from a self-built waveflow flume. • Computational and experimental investigations were conducted on the local scour development and characteristics of submarine pipelines in the Yellow River Delta silty sandy seabed. The effects of different water depths, flow velocities, and pipeline suspension heights on the local scour characteristics of submarine pipelines were compared and analyzed.
• The physical and mechanical properties of silt and sand from the Yellow Sea are measured and microscopically explored. • After the direct shear test, it is found that the section surface of sand becomes rough, with many “V”-shaped cracks. Many particles of the silt structure appear on the surface and tend to disintegrate. • The X-ray diffraction experiment reveals that the compositions of sandy and silty soils are different.
• Bibliometric analysis of research on urban underground space was conducted by knowledge mapping. • An interdisciplinary intersection framework for urban underground space research has been proposed. • The challenges and trends of research on urban underground space have been summarized. • The evolution of urban underground space research in different literature databases has been profiled. • The research results serve as a blueprint showcasing the development of research on urban underground space on a global scale.
• A uniform wear design method of all cutters on the cutterhead for shield tunneling in sandy–pebble stratum was established, that is, the uniform wear of all the cutters can be achieved by installing a certain number of cutters on different trajectory radii of the cutterhead and designing the curved spoke with a certain arch height. • Based on Beijing Metro Line 19, an engineering discrete element method simulation model of shield tunneling in sandy–pebble stratum was established to study the cutters’ wear combined with engineering observations, and the rationality of the uniform wear design method was verified by comparing with the original engineering scheme. • The long-distance shield driving was predicted by the Japanese Tunnelling Society model, and the calculation result of the uniform wear scheme was 47% higher than that of the engineering scheme, which showed the superiority of the uniform wear design method.
• A simulation of the construction process of a shield tunnel and a shallow tunnel traversing beneath an existing underground carriageway is carried out. • The torsional deformation features of the existing structure are studied. • The mechanism and influence pattern of the “shield effect” of the existing structure on stratum subsidence are examined.
• A 30:1 underwater immersed tunnel model was built and 140 sets of fire model experiments were conducted to reproduce various scenarios of tunnel fires. • The diffusion law of smoke was studied. Without ventilation, smoke is effectively blocked by the smoke exhaust cross section and controlled within 2–3 smoke prevention intervals. • The aims of this work are to study the smoke exhaust effect, compare the smoke exhaust effects of different ventilation air volumes and fan operation modes, and summarize the best smoke exhaust plan.