预应力筋布置对曲线刚构桥受力和变形的影响研究

The influence of layout for prestressing tendons on the stress and the deformation of curved rigid frame bridge

曲线刚构桥是一种受力复杂的结构体系,一方面预应力效应能提高结构的承载能力,另一方面也会给结构带来一些不利影响。针对曲线刚构桥弯-扭耦合的力学特点,以冻青树左线——曲线预应力混凝土刚构桥为背景,基于空间有限元方法分析了主梁在运营阶段的受力和变形。分别研究了不对称张拉、不对称布筋、腹板钢束下调等不同预应力设置方案对主梁扭矩、支座反力、径向位移、竖向位移及扭转角的影响,并比较了不同方案下的计算结果差异。通过对预应力效应进行分析,得出了一些有益结论,可为完善曲线预应力混凝土刚构桥的设计和施工提供依据。

Curved rigid frame bridge is a complicated spatial structural system. The effect of prestressing may improve the bearing capacity of the members, but may also adversely affect the structure. In order to study the mechanical characteristics of curved rigid frame bridge,a long span curved prestressed concrete rigid frame bridge is selected as the research background,and the stress and the deformation of the main beam in the operation stage are analyzed based on the spatial finite element method. The influence of different prestress setting schemes on the main beam torque, the support reaction, the radial displacement, the vertical displacement and the torsion angle of the main beam are studied,and the calculation results under different schemes are compared. According to the analysis results of the prestress effect,some useful conclusions are obtained,which can be taken as reference for improving the design of curved prestressed concrete rigid frame bridges.