Abstract:

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.