预应力混凝土桥梁腐蚀后的受力性能分析

结合某铁路大桥预应力钢丝锈断后梁体的受力性能分析,对预应力混凝土桥梁腐蚀后的耐久性评估方法进行了探讨。首先,用静载试验加载方法对腐蚀梁体进行了实桥试验,分别对每孔2片T型梁的跨中挠度、支座压缩量、跨中及L/4截面混凝土应力、内梁预应力钢丝锈断截面处的混凝土应力进行了测试;然后,对受腐蚀预应力混凝土桥梁进行了有限元分析。介绍了正常梁体和腐蚀梁体的有限元模型、有限元网格剖分建立。在预应力梁体的耐久性分析中,应重点考虑预应力筋锈蚀的影响,并给出了预应力筋的简化分析模型。通过对梁体有限元计算结果和试验值的比较,验证了计算模型基本上能准确地反映梁体的受力情况,说明可以采用有限元方法对预应力混凝土桥梁腐蚀后的耐久性进行评估。

Stress Performance Analysis on Corroded Pre-stressed Concrete Beam

The durability assesment methods of corroded pre-stressed concrete beams were explored referring to stress pefformance analysis on corroded pre-stressed concrete beams of a railway bridge. Experiments on the corroded beams were first carried out with static loading method at mid-span deflection of two T-beams, bearing decrement, mid-span and L/4 cross section. The concrete stress of the cross section where pre-stressed with steel wire fractured was also tested. The finite element on the corroded pre-stressed concrete beam was then analyzed. Finite element models of non-corroded beams and corroded beams including the mesh of finite element models ,were presented. In the durability analysis, the influence of the corroded pre-stressed steel wire should be emphatically considered. The simplified model of pre-stressed reinforcement was provided too. Comparing experimental results with finite element calculation results, it concluded that the calculation model could verify the stress condition of the beam, and the durability of pre-stressed concrete beams could be assessed with the finite element analysis.