Rectification of a Slanted Box-Girder Bridge Caused by Unbalanced Soil Load

Rectification of a slanted continuous concrete box-girder bridge is presented in this paper.

Several bridge piers slanted due to uneven ground settlement, inducing excessive width of some expansion joints and oversize sliding displacement of some bridge bearings. The uneven ground settlement occured due to the unbalanced soil load on the ground.

In this project, reverse ground loading was first applied to produce opposite-direction deformation of the bending bridge piles, thereby rectifying the slanted bridge piers rigidly connected to the piles. The procedure was accelerated by constructing several stress release holes on the opposite side of the reverse ground loading.

To stabilize foundation and prevent landsides of riverbank, combimationn of jet grouting piles and deep mixed piles was apliied to reinforce foundation soil, providing lateral restraint on the bridge piles as well. Finally, a hydraulic power system was used to reset the bridge piers, girders, and expansion joints. A similar system and additional equipment were used to replace the damaged bridge bearings.

The recommended rectification techniques are suitable for rectifying bridges with similar geotechnical conditions and structure types and for replacing damaged bridge bearings.