CFRP索预应力斜拉桥徐变分析

为了对CFRP索斜拉桥时效影响之一的徐变特性进行分析,首先考虑了CFRP索几何非线性,采用Burgers四元件模型和Norton理论,介绍了CFRP索蠕变分析理论;其次采用龄期调整有效模量法,推导了由徐变引起的单元杆端力与位移、时间之间的关系式,介绍了混凝土徐变分析理论。通过实测值与计算值的比较,对施工过程和使用阶段主梁应力和变位、索力进行了分析,进而分析了徐变对主梁和索力的影响,结果表明,主梁应力和变位的测试值与计算值吻合较好,施工过程良好,该桥运行情况较好,徐变对索力以及中跨影响较大。CFRP索蠕变变形不明显。同时,还利用ANSYS软件对该桥进行徐变分析,得出了徐变曲线,为徐变分析提供科学依据。

CREEP ANALYSIS OF PRE-STRESSED CABLE-STAYED BRIDGE WITH CFRP CABLES

In order to analyze time-dependent effects of creep of cable-stayed bridge with CFRP cables,first,based on the geometric nonlinearity,four-element burger model and Norton method were conducted to perform creep method of CFRP cable.Then age-adjusted effective modulus was used to produce formula of cell force,displacement and time affected by creep,to perform creep method of concrete.Through comparing test results with calculation results,stress and deformation of main beam and cable force during construction process and use stage were analyzed,thus,the analysis of creep effect on main beam and cable force was performed. Good agreement is achieved.Construction process and use stage are good.Creep effects on cable force and mid-span are greater.Creep deformation of CFRP cables is not obvious.ANSYS software was also used to analyze creep performance of the bridge.A creep curve was derived,which provides a foundation for analyzing the effects of creep.