火致拉索破断斜拉桥安全分析

发布时间：2018-03-29 00:16

本文选题：斜拉桥　切入点：火致拉索破断　出处：《公路工程》2017年04期

【摘要】：通过试验确定拉索着火后的温度场变化,建立了一座斜拉桥模型,采用单根或多根钢绞线逐渐破断的方式进行结构非线性动力分析,研究拉索着火破断后的结构安全性。引入动力放大系数(DAF)和需求能力比(DCR)分析主梁、主塔以及拉索的动力响应,研究了不同断索路径下的桥梁极限承载情况,计算了相邻拉索不同着火时间破断时桥梁结构动力响应,得出外索着火破断比内索着火破断更危险,整根拉索一次破断的模式不适合模拟斜拉桥拉索着火破断的情形。
[Abstract]:The temperature field of cable after ignition is determined by experiments, and a model of cable-stayed bridge is established. The nonlinear dynamic analysis of the structure is carried out by means of breaking of one or more steel strands gradually. In this paper, the structural safety of cable after breaking fire is studied. The dynamic response of main beam, main tower and cable is analyzed by introducing dynamic magnification factor (DAF) and demand capacity ratio (DCR), and the ultimate load bearing condition of bridge under different cable broken paths is studied. The dynamic response of bridge structure with different ignition time of adjacent cables is calculated. It is concluded that the fire breakage of external cables is more dangerous than that of internal cables, and the mode of single break of whole cable is not suitable for simulating the situation of cable fire breaking in cable-stayed bridges.
【作者单位】：湖南大学土木工程学院;
【分类号】：U448.27

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