中文摘要：

穿越不良地质体及地层结构界面是海底隧道修建的关键问题，对其准确地探测、预报并采取可靠的注浆加固方案及施工方法是海底隧道安全顺利施工的重要保证。然而海底隧道施工过程中的地层沉降控制，尤其是不良地质段的地层沉降控制则是海底隧道施工的核心技术之一，它不仅对施工安全至关重要，而且对隧道运营阶段的结构受力及长期安全性也是极其重要的。针对海底隧道的特点，分别从结构界面沟通、地层过度变形以及地层坍塌等方面对隧道突水特点进行了阐述，揭示海底隧道施工中的突水机制；采用现场实测、数值模拟和理论分析方法揭示隧道开挖引起的上覆地层整体变形规律和突水诱发机制，并提出不同地层的沉降控制标准及其确定方法；建立地层开裂与变形的对应关系，为突水事故的预测预报提供了依据；系统分析注浆加固圈厚度对地层沉降的影响关系，并据此提出海底隧道不良地质段的地层加固范围；结合大断面海底隧道的工程特点，制定了隧道施工工艺和监控方案；最后指出海底隧道穿越不良地质段的施工技术要点和紧急预案。上述技术方案和措施在厦门翔安隧道穿越F1风化槽的设计和施工中得到了成功的应用，取得了理想的效果。

英文摘要：

Passing through unfavorable geologic bodies and strata interface is the one of the most difficult problems during subsea tunnel construction. So tunnel geological forecast ahead, grouting reinforcement schemes and construction method optimization are important issues to guarantee the safety of subsea tunnel construction. The control of strata settlement induced by tunnel construction especially for some unfavorable geologic bodies is one of the key techniques during tunnel construction. How to control strata settlement is not only important to the safety during construction period, but also is crucial to long-period safe tunnel operation. According to the characteristics of subsea tunnel, the essence of the inrush of water during subsea tunnel construction is disclosed from the view of the connectivity of strata interface, strata settlement and cave-in, etc.. By using in-situ measured data, numerical simulation and theoretical analysis method, the mechanism of integral deformation of upper strata due to tunnel excavation is then expounded： and subsequently settlement control standard and its determination method for different strata are proposed. The relation between surface crack space and strata displacement is presented to offer guidelines to water inflow prediction. The relation between the thickness of grouting circle and strata settlement is also given to determine the optimal grouting circle thickness for unfavorable geologic bodies. Besides, combined with the characteristics of large-span cross-section of subsea tunnel, tunnel construction technology and monitoring schemes are therein shown. Finally, construction techniques that are used for tunnel passing through unfavorable geology bodies are indicated. The application of above-mentioned technological schemes and measured data are proven to be successful in passing through the weathered slot F1 of Xiamen Xiang＇an subsea tunnel.