海底盾构隧道钢-聚丙烯混杂纤维-钢筋混凝土管片结构高温阻裂机理与性能演化规律研究

海底盾构隧道是未来我国隧道工程的重要发展方向，对于助推海洋强国和交通强国建设具有不可替代的重要作用。然而，在海水长期高压、侵蚀作用和火灾等突发灾害的打击下，普通钢筋混凝土管片的耐久性、安全性面临严峻挑战。钢-聚丙烯混杂纤维-钢筋混凝土管片作为一种良好的主动防护手段，是目前解决该技术问题的重要方案，但是，其在海蚀、火灾高温作用后的性能劣化演化规律与特征仍有待探明。本项目拟从钢-聚丙烯混杂纤维-钢筋混凝土管片材料、构件、原型结构等多个层面开展系统试验与理论研究，探明其结构在海蚀作用下的损伤演化规律，揭示火灾高温时腐蚀管片的细观阻裂机理与宏观爆裂现象，探明高水压海蚀作用下管片结构火灾高温时（后）的灾变机制，提出结构劣化状态与安全性分级评价指标、探明不同修复方法的可靠性，并最终建立海底盾构隧道钢-聚丙烯混杂纤维-钢筋混凝土管片结构的安全性评价方法，以保障海底盾构隧道衬砌结构的耐久性与长期运营安全。

Subsea shield tunnel is an important development direction for the future tunnel engineering in China, which has an irreplaceable role in promoting the powerful support for building China’s strength in maritime power and transportation. However, the durability and fire resistance of reinforced concrete segments are not enough to cope with the severe challenges under the impact of long-term high-pressure sea-water erosion and other sudden disasters especially for the high temperature of fire. The steel-polypropylene hybrid fiber reinforced concrete (SP-HFRC) segment is considered as a superior active protection and is an important solution to the current technical issue, however, its structural behavior deterioration law and characteristics after the effects of chloride erosion and high temperature during fire need to be investigated urgently. This research plans to conduct systematic tests and theoretically studies in multiple levels from the materials and components to prototype structures of SP-HFRC segments, to firstly study the structural damage evolution mechanism under marine environmental erosion, then to reveal the meso-scopic anti-cracking mechanism and macro explosive spalling characteristic of corroded SP-HFRC segments at high temperature in fire, and to unravel the damage mutation mechanism of corroded SP-HFRC segmental lining structure at (or after) high temperature under high water pressure and chloride erosion, then the evaluation indexes of structural deterioration status and safety classification will be put forward and the reliability of different repair methods will be proposed. Correspondingly, the safety evaluation method of the SP-HFRC segmental lining structure can be established for the subsea shield tunnels in order to ensure the durability and long-term operation safety of their lining structures.