Method for main arch closure of three-span hinged arch bridges by adoption of pre-descended and pre-deflected side-span steel trusses

Abstract

The invention discloses a method for main arch closure of three-span hinged arch bridges by adoption of pre-descended and pre-deflected side-span steel trusses. The method includes the steps: pouring side piers of two side spans, reserving post-pouring sections at the top of the side piers, and arranging temporary piers between each side pier and a main pier; enabling one side span steel truss to deflect towards a midspan direction by a pre-deviation distance in initial erection, enabling the two side span steel trusses to descend at the positions of the side piers by a pre-descending distance, and when the steel trusses are erected to the main pier, fixing fixed hinge supports on one side while temporarily fixing movable hinge supports on the other side, and adopting a first jack to jack the steel trusses to separate from the temporary piers; hoisting and erecting the steel trusses to a main arch closure position, and enabling the first jack to jack the steel trusses so as to realize main arch closure; unfixing the movable hinge supports, enabling the first jack to jack the steel trusses to a standard height, pouring the side piers, and freeing the first jack. The method has the advantages that safety and precision in main arch closure are achieved without adjustment of cables or monolithic movement of main truss arches, and accordingly construction risks are reduced while construction period is shortened.

Description

technical field [0001] The invention belongs to the technical field of bridge construction, and relates to a method for closing the main arch of a three-span hinge-supported arch bridge, in particular to a method for realizing the height of the main arch by adopting pre-dropping and pre-deviating side-span steel girders for a three-span hinge-supported arch bridge. The construction method of precision stress-free closure. Background technique [0002] Steel truss arch bridges are very complex in structure and stress. When the main arch is closed, there are many closing points and many influencing factors. It is difficult to construct and control the stress-free closing. At present, the conventional closing construction method for the construction of three-span hinged bearing arch bridges is as follows: steel girders are erected from the side span to the mid-span, and to the mid-span closing, the side spans are erected with temporary piers, and the mid-span is erected by the ...

AI Technical Summary

Problems solved by technology

Among them (1) adjusting the cable force of the cable-stayed buckle-hanging system often increases the cable force, increases the risk, and greatly increases the construction period; The buckle-hanging cooperation system, the structural system is complex in force, the overall stability is weak, and the tonnage of the overall moving beam is also large, and the construction risk is high

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