小洋山隧道在国内首先使用了叠合式中墙（为避免与设计规范复合式中墙相混淆）双连拱隧道结构形式。对于这种新颖的隧道结构，施工方案及施工方法的合理确定尤为重要，是贯彻设计原则、实现设计意图的关键。详细阐述叠合式中墙双连拱隧道的施工方法的确定（设计原则和方法，总体施工方案），施工方案的实施（合理确定施工步距、采用控制爆破技术以减少后行隧道施工对先行隧道衬砌及中墙的影响，采取一定措施解决先行隧道的不对称受力问题），同时阐述了施工监测及隧道防排水要点。小洋山隧道的成功实施丰富了山岭隧道的设计内容。

Xiaoyangshan tunnel is the first doublearched tunnel with superposed partition wall (“Superposed partition wall” is used in the paper to distinguish from the composite partition wall specified in “Design Specification for Highway Tunnel”) in China. Regarding the innovated tunnel structure, it is very important to select proper construction scheme and proper construction methods, which is the key to follow the design principles and to realize the design targets. In the paper, the determination of the construction methods (including the design principles and design methods and the general construction scheme) and the execution of the construction scheme (including the determination of proper distances between different working faces, execution of controlled blasting so as to minimize the influence on the completed lining and partition wall imposed by the construction of the subsequent tunnel and taking proper measures to overcome the asymmetrical loading of the firstexcavated tunnel). Furthermore, the key points of construction monitoring and waterproofing and drainage of the tunnel are expounded. The successful construction of Xiaoyangshan tunnel enriches the design of mountaincrossing tunnels.