大跨度曲线刚构桥预应力设置对扭矩的影响  

Influence of Prestressing Tendon Layout on Torsion Moment of Long Span Curved Rigid-Frame Bridge

作　　者：杨孟刚[1] 陈庚[1] 

机构地区：[1]中南大学土木建筑学院,湖南长沙410075

出　　处：《桥梁建设》2010年第3期15-18,共4页Bridge Construction

基　　金：国家自然科学基金资助项目(50908231)

摘　　要：为了减小曲线梁桥的弯-扭耦合效应,以一座大跨度曲线连续刚构桥为依托,采用有限元软件MIDAS建立空间有限元模型,计算得到自重、预应力、混凝土收缩徐变等荷载作用下的主梁扭矩分布,结果表明:曲线刚构桥主梁的扭矩主要由自重和预应力产生,且随着曲率半径的减小显著增大。因此,改变预应力筋的设置方式是抵消主梁扭矩的一种有效措施,通过不同方式改变原设计方案的对称布筋方式,得知采用预应力筋的不对称张拉以及不对称布筋方式能有效抵消恒载产生的扭矩。To reduce the bending-torsion coupling effect of curved girder bridge,a long span curved continuous rigid-frame bridge is cited as an example and the finite element software MIDAS is used to establish the spatial finite element model for the type of the bridge.The torsion moment distribution in the main girder of the bridge under the load action of dead weight,prestressing tendons,concrete shrinkage and creep is calculated.The results show that the torsion moment of the main girder is mainly caused by the dead weight and prestressing tendons and the moment dramatically increases with the decrease of the curvature radius.Therefore,the changing of the prestressing tendon layout will be an effective measure to counteract the moment and it is known that by changing the symmetric prestressing tendon layout in the original design in a different way,the asymmetric layout and tensioning of the prestressing tendons can effectively counteract the torsion moment caused by the dead weight.

关 键 词：曲线桥 刚构桥 预应力 扭矩 弯-扭耦合 

分 类 号：U448.23[建筑科学—桥梁与隧道工程]