钢筋混凝土肋拱桥静动载试验与评估

以一座3跨100m上承式钢筋混凝土肋拱桥为例,对其进行了静动载试验和计算评估。静载试验中,测试并分析了主拱圈和桥面板控制截面的挠度和应力。动载试验中,测试并分析了该桥的自振特性以及行车激振下的冲击作用。根据实测拱轴线坐标,考虑温度、混凝土收缩徐变等因素,对3跨连拱进行仿真分析。比较分析试验和仿真计算结果表明:该桥在承载能力极限状态下,主拱圈拱脚附近截面承载能力不足,桥面板承载能力能满足设计要求;在正常使用极限状态下,主拱圈和桥面板具有足够的强度和刚度;结构整体受力处于弹性状态,具有良好的动力性能;静动载试验和仿真计算相结合的评估方法可以准确而全面地评定结构性能。

Assessment and static-dynamic test of a reinforced concrete ribbed arch bridge

A 3×100 m three-span deck type reinforced concrete ribbed arch bridge,is taken as an example,to study the static-dynamic test and calculation assessment.The deflection and stress of the control sections of main arch and deck are tested and analyzed under static loads.The natural vibration of the structure is tested,and the impact of the passing vehicles is analyzed under dynamical loads.According to the measured coordinates of arch axis,we simulated the three-span multiple arch bridge by taking into account the influence of temperature and concrete shrinkage and creep.The test and simulation results showed that,firstly,when the bridge was in the ultimate limit state of carrying capacity,the section carrying capacity of the main arch foot is not enough,but the carrying capacity of the deck satisfied the design requirements.Secondly,when the bridge was in serviceability limit state,both the main arch and the deck had enough strength and stiffness,the whole structure worked at elastic state and had favorable dynamical behavior.The assessment method,which combined the static-dynamic tests and the computer simulation,can provide accurate and comprehensive assessment of the structure performance.