ABSTRACT
Construction of underpass crossing existing heavy traffic lanes in dense urban area is challenging. The pipe curtain-box jacking method (PCBJ) is an innovative method for underpass construction and has been applied in several projects, because it causes a low ground disturbance. In large section PCBJ projects, the interaction between backup structure and surrounding soil is related to the stability of the whole soil-structure system, which determines the success or failure of the project. This article presents a case study of an ongoing project of a large and shallow PCBJ underpass (19.6m wide, 6.4m high and 6.3m buried depth) that crosses the Mid-ring Road in Shanghai China. Three-dimensional numerical modeling is performed, replicating the actual condition of the project to the greatest extent. This article also analyzes the deformation of the soil within the area affected by the jacking force, and the stress state of the backup structure.
