Abstract: Static reliability analysis was carried out for the maximum deflection of main girder of three—tower suspension bridge by response surface method(RSM)．The law of main girder’S deflection was studied with the variation of structural parameters such as material properties，geometric dimensions and external load，etc．The results demonstrate that the static deflection reliability was controlled by the load case when the live load was uniformly distributed on one central span girder． It was concluded that the variation of modulus of the main cable，the live load，the area of the main cable and the modulus of the central tower had significant effect on the deflection of main girder of three·tower suspension bridge．

Key words: suspension bridge, deflection, static reliab ility, failure probability, response Sllrface method

摘要： 采用响应面法对三塔悬索桥主梁最大挠度进行静力可靠度分析，考察三塔悬索桥主梁最大挠度对结构材料、 几何尺寸及外荷载等不确定因素的变异而发生变化的规律。结果表明：三塔悬索桥主梁最大挠度可靠指标是由单 主跨施加活荷载控制的，主缆弹性模量、汽车活荷载、主缆截面面积及中塔弹性模量等对主梁最大挠度的影响最为 显著。

关键词: 悬索桥, 挠度, 静力可靠度, 失效概率, 响应面法