对于高等级公路隧道通常采用上、下行隧道分离的双洞结构，但由于施工场地狭窄等原因使得双洞分离受到限制时，一般设计为双连拱隧道。然而，相对于分离式隧道，双连拱隧道施工中存在对围岩的扰动次数多、结构受力复杂、防排水困难等技术问题，故施工中具有相当大的难度，尤其在浅埋、软弱围岩条件下，这类隧道在不同的施工阶段围岩与支护体系的稳定问题就备受关注。主要对南友高速公路六尖山双联拱隧道施工的技术问题进行探讨。

Structures consisting of twin separated tubes are usually adopted for highway tunnels. Due to the space constraints of the job site, however, doublearched tunnels are often adopted. In contrast to tunnels consisting of twin separated tubes, the construction of doublearched tunnels has such technical problems as frequent disturbing of the surrounding rock mass, complex structural forceundertaking and great difficulties in waterproofing and drainage, therefore there exit great difficulties in the construction of doublearched tunnels. Public focus is placed especially on shallowburied doublearched tunnels in soft ground in respect of the stabilities of the surrounding rock mass and the reinforcement structures. In this article, discussions are made on the construction technology of Liujianshan doublearched tunnel on NanningYouyiguan Highway.