Rigid Spliced Box Girder Bridge under the Action of Foundation Settlement Difference Analysis of Mechanical Behavior of Splice Section

In a main line viaduct widening project, the old bridge is 35m+55m+35m three-span variable section prestressed concrete continuous box girder, which has the characteristics of large width, long span, variable section of beam body, large cantilever (4.05m), and transverse prestressed steel beams arranged on the bridge panel, etc. The old and new box girders adopt rigid joint scheme. Articles on rigid splicing box girder bridge in foundation settlement under the action of splicing mechanical properties to carry out the finite element analysis, the results show that the new bridge under the action of foundation settlement difference, longitudinal pier fulcrum position splicing under high horizontal stress, transverse middle fulcrum section splicing appeared transverse stress peak period of angular point position, may result in the crack of the concrete; There is a linear relationship between the level of additional internal force and the settlement difference of foundation, which is about 0.95MPa/mm. The calculation stress value of splicing segment can be reduced by reducing the thickness of splicing segment. In practical engineering, control and adjustment measures such as preloading of new bridge structure and selecting adjustable high support can be used to improve the force condition of splicing section[1][2].