盾构隧道接缝密封垫张开渗流细观机理与精细化模型研究

Recently, a very large number of subways, underground roads and cross-river, cross-sea shield tunnels are constructed and become into operation, and tunnel segment joint waterproof, deformation, opening and dislocation, leakage are a frequently encountered serious problem in soft soil layer. This application is aimed to clear the Mesomechanism of the segment joint and rubber waterproof gasket opening and seepage, based on the mechanics and seepage coupling theory, the mechanical and deformation behavior of each detail of the joint component is considered, the water pressure crack and seepage process of the joint contact surfaces and rubber gasket contact surfaces is simulated with the cohesive element, thereby the fine theoretical model and numerical simulation method of the segment joint and rubber gasket opening and seepage are established through secondary development of existing software. Finally, the rationality of the fine model and simulation method is modified and testified by laboratory model test and engineering practices. The fine theoretical model meets the urgent need of advance in theory and technology to solve the segment joint waterproof problems of the complicate urban environment sharp curve, cross-river high water pressure, or future cross-sea ultrahigh hydrostatic shield tunnel, it improves the level of design, construction and operation of shield tunnel.

当前地铁、地下道路与越江跨海盾构隧道大量建设并进入运营，管片接缝防水、变形、张开错台、渗漏等是软土盾构隧道经常遇到且影响十分严重的问题。本项申请旨在弄清盾构隧道管片接缝及橡胶密封垫变形张开渗流的细观机理，基于力学与渗流耦合理论，考虑接缝各细部构件力学变形性态，以及接缝接触面、密封垫接触面水压张开渗流过程，建立可模拟接缝及密封垫接触面水压裂缝扩展的cohesive单元，从而建立盾构隧道管片接缝及橡胶密封垫张开渗流的精细化理论模型与方法，通过已有软件的二次开发，实现能准确预测管片接缝及密封垫受力、变形张开、渗流发展过程规律的精细化数值模拟。最后，通过室内模型试验与工程实例完善和验证所建立的精细化模型和分析方法的合理性，为目前迫切需要通过理论与技术的进步，以解决的城区复杂环境急曲线、越江高水压、未来跨海超高水压盾构隧道接缝防水难题提供精细化的理论模型基础，提高我国盾构隧道设计、施工与运营水平。

项目针对地铁、地下道路与越江跨海盾构隧道管片接缝防水、变形、张开错台、渗漏等问题，研究团队主要围绕盾构隧道衬砌结构管片接缝的防水失效和力学变形破坏这一核心问题，开展了一系列相关理论研究、试验与技术创新，深入揭示了接缝及密封垫张开变形以及在侧向水压作用下的渐进张开渗漏细观机理与规律，开展了盾构隧道接缝张开变形破坏及防水系列试验，考虑接缝各细部构件力学变形性态以及密封垫接触面水压扩展，建立了盾构隧道及其管片接缝张开变形、防水能力的精细化有限元计算模型与三维数值模拟方法，进而提出了考虑长期效应的盾构隧道接缝防水密封设计方法。项目通过室内模型试验与实际工程应用完善和验证了所建立的试验技术、理论模型和分析方法的合理性。项目共计发表学术论文17篇（其中SCI收录5篇、EI收录8篇），主编ASCE 国际学术会议论文集1部；授权发明专利1项，公开发明专利受理4项，授权实用新型专利6项。培养博士4名，硕士4名；项目相关成果国内学术会议特邀报告3个，国际学术会议特邀报告3个。在本项目的联合资助下，相关成果指导了上海北横地下道路隧道、上海深层排水盾构隧道（内外水压双道防水）以及我国最大埋深（80 m）的盾构法水下隧道—苏通GIL综合管廊长江隧道的接缝密封垫设计选型，项目完成了要求的全部考核指标与成果，为大直径高水压盾构法隧道工程的设计与安全施工和运营提供了重要的技术保障。