Variable cross-section box girder bridge closure segment construction method

Abstract

The invention belongs to the field of bridge engineering construction and particularly provides a variable cross-section box girder bridge closure segment construction method. The method comprises the following steps of side span closure segment formwork mounting, side span stiff skeleton welding, side span reinforcing steel bar machining and mounting, transverse and vertical side span prestressed tendon mounting, side span closure segment concrete pouring, side span closure segment prestressing tendon tensioning and pipeline grouting, midspan closure hanging basket moving and balance weight arranging, midspan closure segment pushing, midspan closure segment concrete pouring, midspan closure segment prestressing tendon tensioning and midspan closure segment formwork and support dismantling. According to the method, jacks are adopted for jacking beam ends, stiff skeletons are additionally arranged in beams, the tensioning procedures are reasonably designed, the bearing capacity of a closure segment is effectively guaranteed, the number of engineering accidents is reduced, the adverse social influence produced after the accidents is eliminated, and good social benefits are achieved.

Description

technical field [0001] The invention belongs to the field of bridge engineering construction, and in particular relates to a construction method for the closure section of a variable-section box girder bridge. Background technique [0002] Long-span high-pier prestressed concrete continuous box girder bridge is the most competitive bridge type across deep ditches, rivers, lakes and seas. Due to the impact of concrete shrinkage and creep, the main pier of this type of bridge is deviated greatly after the completion of the bridge, which makes the stress on the bottom of the pier and the pier-beam consolidation extremely unfavorable. At the same time, due to the temperature drop, tensile stress is generated inside the box girder. During the construction of the mid-span and closing section of the bridge, the construction effect of the tensioned mid-span prestressed steel beam is greatly affected by the unfavorable influence of the fixed support end of the pier pier, and the idea...

AI Technical Summary

Problems solved by technology

During the construction of the mid-span and closing section of the bridge, the construction effect of the tensioned mid-span prestressed steel beam is greatly affected by the unfavorable influence of the fixed support end of the pier pier, and the ideal prestressed construction effect is often not achieved, which greatly limits the continuous box. bridge span