悬臂浇筑预应力混凝土曲线连续箱梁桥设计要点分析

Analysis of Design Points of Cantilever Concreting Prestressed Concrete Curved Continuous Box Girder Bridge

悬臂浇筑预应力混凝土曲线连续箱梁桥除了具备常规悬浇桥的受力特点,还具备预应力弯桥的受力特点。采用空间软件Midas Civil建立了悬臂浇筑预应力混凝土曲线连续箱梁桥上部结构有限元模型,对桥梁在施工阶段和成桥运营状态下的受力情况进行了计算分析。以合理成桥状态为基础,分析施工阶段和运营阶段支反力差值过大的原因,并针对结构受力特点提出了主墩设置支座偏心的设计措施。对预应力混凝土连续梁常见病害成因进行了分析,并提出了加强钢束防崩钢筋配置、优化顶板束和普通钢筋布置以及优化腹板普通钢筋配置等设计措施,以期为同类桥梁的设计提供参考。

Cantilever cast prestressed concrete curved continuous box girder bridges have the mechanical characteristics of conventional cantilever cast bridges besides the mechanical characteristics of prestressed curved bridges.A finite element model of the upper structure of a cantilever cast prestressed concrete curved continuous box girder bridge was established by the spatial software of Midas Civil to calculate and analyze the stress conditions of the bridge during construction and operation.Based on the reasonable completion state of the bridge,the reasons for the large difference in support reaction forces were analyzed during the construction and operation stages.According to the structural stress characteristics,the design measures for the eccentricity of the main pier support were proposed.The causes of common diseases in prestressed concrete continuous beams was analyzed in this paper.Design measures such as strengthening the configuration of anti collapse steel bars for steel tendons,optimizing the layout of top plate tendons and ordinary steel bars,and optimizing the configuration of ordinary steel bars for web plates were proposed in order to provide reference for the design of similar bridges.