中文摘要：

为求解连续刚构桥梁跨中成桥预拱度设置值，将影响其运营期间跨中挠度值增大的多种主要因素（包括结构刚度下降、混凝土收缩徐变、预应力损失）给定合理量值并考虑相互耦合作用，建立多种不同跨径组合的在役刚构桥梁有限元模型，对其进行分析求解．有限元求解所得的大量离散数据表明，混凝土收缩徐变是连续刚构桥梁梁体下挠的最主要影响因素，且收缩徐变引起的跨中下挠量与跨径有明显的函数关系，预应力损失对其影响次之，刚度折减对跨中长期挠度影响不大．利用最小二乘法进行多项式拟合，最终推导出适用于主跨跨径200m以内的连续刚构桥梁跨中成桥预拱度估算公式，并与规范解、经验解、实测值进行对比，证明了该估算公式的适用性．

英文摘要：

In order to solve the pre-eamber value at the mid-span of the completed continuous rigid frame bridge,a variety of influencing factors including the decrease of structural stiffness, shrinkage and creep of concrete and the loss of prestress are considered. By modelling different combinations span finite element structure,we give a reasonable amount of factors value and consider their mutual coupling effect. A large number of discrete data obtained by the finite element method shows that the shrinkage and creep of con- crete are the main influencing factors of continuous rigid frame bridge; and the change value with span have obvious function relation; the influence of prestress loss is the second; the stiffness reduction has little effect on deflection. Based on a large number of discrete data, using least squares method to carry out pol- ynomial fitting, and then the pre-camber in completed bridge stage estimation formula of continuous rigid frame bridge＇s mid-span is deduced. The estimation formula is suitable for main span less than 200 meters. Compared the estimation formula with standardized solution, experience solution and measured values, the applicability of the estimation formula is proved.