复合式直中墙连拱隧道在复杂地形条件下的应用

高速公路连拱隧道可分为整体式和复合式2种主要结构形式，根据中墙的特点，每种结构又可分为直中墙及曲中墙，共4种形式。文章从连拱隧道中墙的构造、连拱隧道跨度、隧道结构防排水3方面对不同结构形式的连拱隧道进行分析比较，阐述不同结构形式的适用条件及优缺点，重点讨论复合式直中墙结构形式连拱隧道在复杂地形及富水地区条件下的优越性。结合工程实例，从设计情况、施工方法及关键部位施工3个方面介绍复合式直中墙连拱隧道在复杂地形条件下的应用及施工技术，为类似工程提供借鉴。

Application of Double-arch Tunnels with Straight Composite Center Pillars in Complex Topographic Conditions

Double-arch highway tunnels can be divided into four types, i. e. , double-arch tunnels with straight monolithic center pillars, double-arch tunnels with straight composite center pillars, double-arch tunnels with curved monolithic center pillars and double arch tunnels with curved composite center pillars. These four types of double-arch tunnels are compared in terms of the center pillar structures, the span of the double-arch structures and the structural waterproof- ing and drainage of the tunnels. The application scopes and advantages and disadvantages of different types of double-arch tunnels are expounded, with the advantages of double-arch tunnels with straight composite center pillars used in complex topographic conditions and water-rich areas being focused. The application technology for double-arch tunnels with straight composite center pillars are presented, on basis of engineering cases, in terms of design, construction method and key position construction. The paper can be served as reference for similar projects in the future.