基于结构退化分析的桥梁长期挠度计算  

Bridge long-term deformation based on structure degradation

作　　者：李源[1] 贺拴海[1] 侯炜[1] 任伟[1] 

机构地区：[1]长安大学公路学院,陕西西安710064

出　　处：《长安大学学报（自然科学版）》2014年第3期53-59,共7页Journal of Chang’an University(Natural Science Edition)

基　　金：交通运输部应用基础研究项目(2012319812100)

摘　　要：针对虎门大桥辅航道桥在运营期间中跨跨中过量下挠问题,通过有效预应力实测数据确定结构整体预应力束损失模型。选取B3收缩徐变模型,同时考虑截面刚度及弹性模量退化,结合有效预应力实测数据,提出考虑结构多因素退化的长期挠度计算方法,对比该计算方法计算结果与结构中跨跨中下挠实测数据,验证计算方法可用性并分析误差原因。研究结果表明:考虑结构四类退化的长期挠度计算方法较传统计算方法更为接近结构下挠实测值,运营过程中预应力正抛物线损失与结构实际下挠相符;考虑基于结构损伤的长期挠度计算结果与结构下挠实际观测值误差在7%以内,中跨预应力损失通常伴随边跨预应力'张紧',这种'张紧'现象对结构长期下挠控制是有利的。Aimed at the problem of excessive long-term deformation,through the measured effective prestress,the regulation of pre-stress in the whole construct was obtained.Using the B3shrinkage and creep model,with consideration of the decline of section stiffness and the variation of the elastic modulus,a structure degradation analysis method was presented.Through the comparison of the calculation results and the measured structure deflection,the feasibility of this method was proved.The causes for the errors were also analyzed.The results show that the results of the method with consideration of structure degradation is more close to the measured structure deflection than traditional one.The parabola loss of pre-stressed concrete structure is reasonable in operation period.The calculation result based on the structure deflection is 7%less than the observed value.The mid-span pre-stress loss is often accompanied by the＂tension＂of the side one,and this＂tension＂phenomenon is beneficial for long-term deflection control.

关 键 词：桥梁工程 结构退化 大跨径连续刚构桥 有限元法 长期挠度 

分 类 号：U488.23[交通运输工程—载运工具运用工程]