XIANG Yi-qiang, YANG Ying, LIN Heng, SHEN Yong-gang
As a novel cross-sea passage structure, the submerged floating tunnel (SFT) offers advantages such as large spanning capacity, strong topographic adaptability, minimal environmental impact, and all-weather operation, and is regarded as an important solution for addressing the challenges of constructing long-distance, deep-water cross-sea passages. However, as an innovative design, its design theories, analysis methods, and construction techniques are not yet mature, and no actual engineering project has been completed to date. This paper systematically reviewed the recent research advances in SFTs in terms of structural design and optimization, dynamic behavior analysis, construction techniques, and structural safety and monitoring. First, the selection principles and applicable conditions of tube cross-sectional forms, anchor cable layouts, deep-water foundation types, and joint configurations were discussed. Second, the structural responses and analysis theories under the individual or combined action of multiple loads, including waves, currents, vehicles, earthquakes, collisions, explosions, and cable rupture, were summarized, and the applicability characteristics of different analysis models and methods were compared. Finally, construction technical schemes such as underwater docking of tube segments and anchoring and tensioning were described, along with explorations in structural safety and intelligent health monitoring system frameworks. In view of the current research status, key technical bottlenecks were identified, including unclear multi-field coupling mechanisms, insufficient large-scale experimental verification, construction techniques that mostly remain at the conceptual stage, gaps in long-term durability research, lack of engineering validation for risk assessment and monitoring, and absence of design specifications. Future research in structural analysis, model testing, intelligent construction, and operation and maintenance was also prospected, with the aim of providing a reference for in-depth exploration and accelerated engineering application in the field of SFTs.
