【摘要】 由于结构复杂、影响因素众多，斜拉桥初始有限元模型不能准确反映实际结构，且服役阶段斜拉桥力学性能持续退化。因此，建立反映斜拉桥真实状态的数值模型是追踪其时变力学性能的关键。故该研究提出基于自适应模型的在役斜拉桥时变力学性能追踪方法。首先根据成桥时拉索实测索力，采用多目标优化法修正斜拉桥成桥时有限元模型。基于修正后的成桥有限元模型，考虑服役阶段混凝土收缩、徐变和环境温度效应，采用有限元逐步分析法数值追踪在役斜拉桥时变力学性能。利用所提出的方法数值评估海河大桥服役1年和2年后时变力学性能，并对该桥实际力学性能进行周期性现场检测。研究结果表明，服役1年和2年后，全桥索力数值结果与现场检测值的相对差异始终保持在±10%之内，主梁挠度数值结果和实测值最大差异分别为-0.025 m和-0.013 m。因此，斜拉桥自适应模型能够有效地追踪在役斜拉桥时变力学性能。在服役阶段，该混合梁斜拉桥主跨主梁挠度逐渐增大，边跨主梁挠度变化很小。更多还原

【Abstract】 Due to complex structure and many influencing factors, cable-stayed bridge’s initial finite element model can’t accurately reflect actual structure, and mechanical properties of in-service cable-stayed bridge continue to deteriorate. Therefore, establishing a numerical model to reflect actual state of cable-stayed bridge is the key to track its time-varying mechanical properties. Here, a method for time-varying mechanical properties tracking of in-service cable-stayed bridge was proposed based on an adaptive model. Firstly, according to measured cable forces when bridge was completed, the finite element model of cable-stayed bridge when it was completed was modified by using the multi-objective optimization method. Based on the modified finite element model of bridge during it being completed, considering concrete shrinkage, creep and ambient temperature effect during service, the finite element step-by-step analysis method was proposed to numerically track time-varying mechanical properties of cable-stayed bridge. The proposed method was used to evaluate time-varying mechanical properties of Haihe Bridge after 1 and 2 years of service, and actual mechanical properties of the bridge were periodically detected on-site. The study results showed that after 1 and 2 years of service, relative differences between cable force numerical results of the whole bridge and on-site detected values are always within ± 10%, and maximum differences between deflection numerical results of main girder and actually detected values are-0.025 m and-0.013 m, respectively, so the adaptive model of cable-stayed bridge can effectively track time-varying mechanical properties of in-service cable-stayed bridge; in service stage, deflection of main girder on main span of this hybrid girder cable-stayed bridge gradually increases, while deflection of main girder on side span changes little.更多还原