Research on Urban Crossing Viaduct Bridge Jacking Technology

Facing the increasingly saturated urban traffic volume to solve the urban congestion situation, the urban viaducts have to be reconstructed to meet the daily traffic requirements. In this paper, taking an urban spanning viaduct reconstruction project as an example, the finite element analysis software Midas Civil is used to set different working conditions to analyze the stress characteristics, and the stability of the whole bridge and the jacking support during the jacking process. Meanwhile, this paper study the difficulties and key technical points of urban viaduct jacking technology and provides technical reference for the application of this technology in similar projects. Research indicates that the main girder stress changes caused by height changes during the jacking process are small within 1 MPa. When the single-side jacking exceeds 60 mm, the jacking support will be bearing empty with varying degrees, ranging from 1 to 3 in this paper. Uneven jacking will cause serious empty of the bridge bearing, the void number of temporary supports near 30 when uneven jacking height up to 10 mm, and it has little influence on the stress variation of the main girder. And it also will cause the phenomenon that the reaction force of some supports is too concentrated, as high as 2000 kN.