Study On The Design And Construction Of Underpass Shed Tunnel Structure Along The River Bank In Urban Areas

As the rapid development of economy and continuously improvement of people's living standard, more efficient and convenient urban transportation was required. However, often due to the shortage of urban land, the development of its transport was limited. This result in a spatial formula traffic mode such as underpass tunnel, and the shed tunnel as a new type of tunnel structure was applied. In this paper, combined with "The Underpass Tunnel Restoration and Reconstruction Project from Bridge 1 to Bridge 2 on Fujiang in Jiangyou City", the author carried out research on the design and construction of underpass shed tunnel structure along the river in the city.This paper set the Shed Tunnel Project along the river in Jiangyou as the background. Combined with the geological survey data, the design and the support measures of the foundation pit of shed tunnel were systematically studied by the theoretical analysis, numerical simulation and other methods. The major research work, achievements and conclusions were as follow:(1) The features and advantages of shed tunnel in the highway construction were reviewed and summarized. For the underpass tunnel project in urban areas, the author comprehensively compared the applicability of three different types of shed tunnel structure (with wall, frame or column as the lateral support).(2) The construction steps and technology of reasonable shed tunnel structure which was along the river in urban areas were researched. Then, a relatively complete construction scheme of shed tunnel was collated and achieved.(3) By the finite element software PHASE2, two different support schemes (soil nailing wall and piles) of shed tunnel excavation which was along the river bank in urban areas were studied. The result indicated that:The shed tunnel with soil nailing wall was safe and reasonable. Not only the revetment function of soil nailing wall was played, but also the retaining of shed tunnel was developed. It formed an entire stress system. Both the stability and security of foundation pit and embankment on the side of shed tunnel was ensured.By virtue of engineering example and numerical analysis, this paper proposed a number of recommendations about the applicability, design and construction of urban underpass shed tunnel structure along the river. It gave some reference to the construction of similar projects in the future.