Research on Key Technology of Incremental Launching Construction of Variable Height Continuous Steel Box Girder Bridge with Non-Closure Segment
The incremental launching construction method,along with structural internal force and geometrical alignment control technologies,applicable to a large-span variable height continuous steel box girder bridge without a temporary pier in the mid-span,is introduced based on a real project.Given the large variation in girder height,the method of rotating elevation alignment of the girder is employed to lower the pad height during the incremental launching construction process.The use of rotating spherical caps and adjustable wedge blocks is implemented to adapt to the curvature of the girder bottom.Addressing challenges such as excessive deflection at the cantilever end,relative altitude differences at the closure segment,and a significant increase in negative bending moment at the cantilever root during the incremental launching construction process,a construction technology is utilized.This technology involves incremental launching from each side span and temporary cables assisted closing,based on the unstressed state control method.The construction approach optimizes the internal force state of the bridge structure and reduces the risk associated with geometrical alignment control.This study also includes an analysis of the local stability of the steel box girder and longitudinal overturning stability,accompanied by proposed strategies.Currently,the bridge has been successfully constructed and opened to traffic.The research findings offer valuable engineering experience for similar bridge projects.
variable height steel box girderincremental launching constructionnon-closure segmentunstressed state control methodtemporary cablegeometrical alignment control
万方数据
维普
