为解决近年来频发的极端暴雨天气导致的城市隧道淹水问题，首先，通过相关文献及新闻报道梳理国内外城市隧道发生淹水致灾的原因和已有城市隧道相关的防淹经验； 其次，对现有全国主要城市关于隧道防淹的现行政策、标准以及城市隧道运营阶段涉及防淹工作的内容进行研究总结。在此基础上，对城市隧道的防淹措施开展研究，将城市隧道防淹措施分为6大系统： 1）挡水系统，提升隧道出地面范围的防洪能力； 2）截水系统，提前截流隧道外部水； 3）排水系统，确保隧道内部排水系统顺畅并满足高标准暴雨重现期的排水需求； 4）控制系统，保证隧道排水系统正常工作的供配电和控制系统； 5）预警系统，增加隧道内外淹水预警装置进行提前防范； 6）应急系统，提出发生淹水事故后的应急保障措施。综合城市隧道养护等级、隧址范围内城市内涝风险等级，确定城市隧道的防淹分级可分为1级、2级和3级，并根据城市隧道的防淹等级确定已有城市隧道的防淹改造方案或待建隧道的防淹设计要求。

In recent years, frequent extreme rainstorms cause flooding in urban tunnels. To address this problem, the authors summarize the causes of flooding disasters and the existing antiflooding experiences in urban tunnels based on relevant global literature and news reports. The current policies, standards, and contents of antiflooding work in major cities across China during the operation stage of urban tunnels are analyzed. Consequently, antiflooding measures for urban tunnels are examined. The antiflooding measures are classified into six major systems: (1) a barrier system to enhance the flood prevention capacity at tunnel exits, (2) a diversion system to divert water outside the tunnel in advance, (3) a drainage system to ensure that the drainage system inside the tunnel functions smoothly and meets the drainage requirements in the highstandard rainfall return period, (4) a control system to ensure the normal operation of the power supply and control system for the tunnel drainage system, (5) a warning system to prevent flooding in advance by increasing the flood-warning devices inside and outside the tunnel, and (6) an emergency system that can ensure timely emergency support measures in flooding accidents. Based on the maintenance grade of the urban tunnels and the flood risk grade within the tunnel site, antiflooding grades of urban tunnels can be classified into Grades Ⅰ, Ⅱ, and Ⅲ. Based on this classification, the upgrading schemes of the existing urban tunnels and the design of the planned tunnels can be determined.