大跨预应力混凝土连续梁桥单墩顶升技术研究

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中图分类号：U445.4文献标识码：A

Research on Single Pier Jacking Technology for Large-Span Prestressed Concrete Continuous Beam Bridges

AI Qinghua，MA Wenfang，HU Jiahuan，YAN Xin （State Key Laboratory of Mechanical Behavior and System Safety of Trafic Engineering Structures， Shijiazhuang Tiedao University，Shijiazhuang，Hebei O5OO43，China）

Abstract： Taking the post earthquake repair project of a prestressed concrete continuous beam bridge as an example，a finite element model of the bridge was established using Midas Civil software. Three working conditions were analyzed， including single pier uplift， single pier uplift+moving load，and single pier uplift + gradient heating. The variation laws of support reaction force，upper and lower edge stress of the beam，and stress of prestressed steel bars were studied. Research has shown that when the bridge pier is lifted，the prestressed steel bars on the top plate of the main beam at the separated pier first break.When the bridge pier is lifted，the concrete on the top edge of the main beam section corresponding to the jack experiences tensile cracking and damage. When the lifting height reaches the requirement for bearing replacement，traffc restrictions must be implemented for passing vehicles when lifting at the bridge pier，and traffic should be interrupted when lifting at the bridge pier.The gradient heating has a relatively small impact on the reaction force of each support，the stress of the lower flange of the beam，and the stress of the prestressed steel bars，while the stressof the upper flange has a greater impact. However，the tensile stress and compressive stress of the upper flange of the beam at the jacking point have a certain positive impact on the jacking construction.

Key words： large-span prestressed concrete continuous beam bridge ; bridge jacking; finite element analysis

地震会使桥梁结构产生不同程度损伤，支座作为桥梁结构的易损构件，在历次地震中，支座破坏现象尤为常见。（剩余10896字）