Wuncunshan tunnel on JC3 bid section of airport Highway in Xiamen, which locates in busy downtown area and goes underneath 67 buildings with shallow foundation, is expected to control the surface settlement caused by tunnel excavation. Multi-arch tunnel method and neighborhood tunnel method were both tested by design and excavation unit in order to understand which is more effective to control the surface settlement. Based on in-situ measurement and numerical simulation, this paper contrasts and analyzes measurement data and numerical results of the two excavation methods including transverse and longitudinal surface settlement and individual effect of sub-hole excavating and dismantlement supports. Some conclusions are obtained, which provide good reference for design and excavation of similar tunnels.
With the development of high-grade highway construction, space between left and right of twin-tunnel can't satisfy the request of permitted limits, owing to the especial geology, landform condition, join means, collectivity line type and engineering cost. Considering of techno-economy and environment benefit, multi-arch tunnel and neighborhood tunnel become important choice schemes, especially in short or medium length tunnel and the adit of long length tunnel.
Multi-arch tunnels are wide application to the special sections of the high-grade highway, since the Baiyushan tunnel in Guangzhou, which is the first multi-arch tunnel in china completed in 1993. Compare to general twin-hole tunnel, multi-arch tunnel requires little of connection landform, and links conveniently and smoothly to outer line. However, there are still some problems including much procedure, frequent transformation of structure force, high construction difficulty and high engineering cost and water leakage of the middle wall.
Neighborhood tunnel is one kind of structural style between the ordinary separate tunnel and multi-arch tunnel, which can reduce construction procedure and lower engineering financing, especially solve the problem of waterproof and drainage completely. However, as neighborhood tunnel has been less built in China, some key construction technologies need further study. The main problem for neighborhood tunnel is that, according to different surroundings, how much space and which necessary measures can meet engineering requirements and guarantee its security.
Wuncunshan tunnel on JC3 bid section of airport Highway in Xiamen, locating in busy downtown area and going underneath 67 buildings with shallow foundation, is required to strictly control the surface settlement caused by tunnel excavation. Multi-arch tunnel method and neighborhood tunnel method were both tested by design and construction unit in order to understand which is more effective to control the surface settlement. This paper contrasts and analyzes monitoring data and numerical result of the two tunnel methods based on in-situ monitoring and numerical simulation, and some useful conclusions for design and construction of similar tunnels are obtained.
Wuncunshan tunnel on JC3 bid section of airport Highway in Xiamen, locating in busy downtown area, is a highway tunnel consisting of 3 lanes in each direction. As the tunnel goes underneath 67 buildings with shallow foundation, the surface settlement caused by tunnel excavation need to be controlled strictly.