预应力混凝土矮塔斜拉桥线形敏感参数研究

Research on Geometry Sensitive Parameters for PC Extradosed Cable-stayed Bridge

以某预应力混凝土矮塔斜拉桥为工程背景,借助有限元程序系统研究了主梁重度与刚度、斜拉索初张力与刚度、温差荷载和预应力效应对成桥状态下主梁线形的影响程度。并将各参数划分为3个敏感等级,将对主梁竖向变形改变量超过10mm的影响参数:正温度梯度、均匀升温、主梁容重和均匀降温列为敏感性I级,这些参数对矮塔斜拉桥成桥线形影响程度最大,并对该类桥梁在施工中关键参数的控制提出合理化建议。

Taking a PC extradosed cable-stayed bridge as the engineering background,the finite element program system is used to study the density and stiffness of the main girder,the initial tension and stiffness of the stayed cable,the temperature difference load and the prestress effect on the geometric alignment of main girder under the bridged state.The parameters are divided into three sensitive grades,and the influence parameters of the vertical deformation change of the main girder exceeding 10 mm are:positive temperature gradient,temperature rising,bulk density of main girder and temperature cooling as sensitivity level I.These parameters have the greatest impact on the bridge geometry of the extradosed cable-stayed bridge and reasonable suggestions for the control of the key parameters of the bridge during construction are proposed.