矮塔斜拉桥施工过程非线性受力数值模拟探讨

Study on Nonlinear Force Numerical Simulation at the Construction Process of the Pylon Cable-stayed Bridge

运用有限元分析软件MIDAS/CIVIL对江珠荷麻溪大桥张拉预应力筋下一段梁浇筑中两个典型的荷载工况进行分析计算,对矮塔斜拉桥的主梁挠度和应力的非线性效应进行分析,结果表明:未进行挂索施工时,箱梁最大张拉应力出现在主梁顶部;随着挂索施工的推进,主梁顶部的应力值不断增大,并由主梁顶部向下,应力值不断增大;当实行浇筑合拢后,主梁拉索固定区出现最大应力;矮塔斜拉桥主梁挠度和应力受几何非线性效应表现出不同特性。几何非线性效应对挠度的影响程度由大到小依次为垂度效应-大位移效应-梁柱效应,此时线性效应对主梁挠度的影响远低于非线性效应的作用;在应力分析中,影响顶板应力的几何非线性因素由大到小为:梁柱效应-大位移效应-垂度效应,影响底板应力的几何非线性因素由大到小为:垂度效应-大位移效应-梁柱效应。

In this paper,using the finite element analysis software MIDAS/CIVIL to Jiang Zhu lotus hemp next creek bridge tensioning prestressed Duan Liang pouring in the analysis of two typical load condition,of short tower cable-stayed bridge girder deflection and stress of the nonlinear effect is analyzed,the results showed that: not to hang rope construction,box girder maximum tension stress appears on the top of the main girder; Along with the construction of the hanging cable,the stress of the top of the main beam increases continuously,and the top of the main beam is downward,and the stress value increases continuously. The maximum stress in the fixed area of the main girder is fixed after the casting is applied. The deflection and stress of girder cable-stayed bridge have different characteristics. The influence degree of the geometric nonlinear effect on the deflection from big to small,in turn,sag effect-large displacement effect-beam-column effect,the linear effect on the influence of the main beam deflection is far less than the effect of nonlinear effect; In the stress analysis,the geometric nonlinear factors influencing the roof stress from large to small is: the beam-column effect-large displacement effect-sag effect,the geometric nonlinear influence factors of floor stress from large to small is: the sag effect-large displacement effect-beam-column effect.