Abstract：Up to now，the subway crossing project through Hongxu Road is a pipe-roof project with the biggest cross-section of box culvert in the world. It is constructed in saturated soft soil stratum in the Beihong Road located in the middle ring-road in Shanghai. During the box culvert being pushed within the steel pipe-roof in the practical construction，the upper pipe-roof presents mainly upheaving deformation. According to analyzing mechanical equilibrium conditions on the culvert and sliding soil mass in front of it，the additional load on the upper pipe-roof is got. One of the upper and middle steel pipes can be thought of as a beam laid conversely on Winkler foundation and pressed by the additional load. The vertical deformation of the upper and middle steel pipe-roof can be predicted by the mechanical model. The theoretical results are compared with the monitoring results during the culvert being pushed. It is found that they are approximately same on variation characteristics and values，which shows the prediction method is reasonable in some degree.
