桥面板约束条件对钢筋混凝土拱桥力学性能影响的试验研究

针对某服役30余年的六跨钢筋混凝土拱桥制作了有机玻璃单跨缩尺模型,考虑桥面板不同约束情况(连续和分段)对拱桥模型开展了静、动力力学性能的试验研究。讨论了不同桥面板约束条件对结构静、动力力学性能的影响。研究表明,桥面板的约束情况对结构的刚度有很大程度的影响,桥面板约束越强,结构的频率越高,结构的动力性能越好;桥面板的约束情况对结构水平向动力特性(包括频率和振型)的影响高于竖直方向;桥面板中部的约束情况对整个结构基本频率的影响最为显著。通过试验结果与原型观测结果的比较,确定了能够较好反映原型结构力学性能的模型结构;为进一步开展钢筋混凝土拱桥损伤识别的模型试验和理论分析研究建立了基础。

EXPERIMENTAL INVESTIGATION ON THE EFFECTS OF DECK CONSTRAINT ON THE MECHANICAL PROPERTIES OF REINFORCED CONCRETE ARCH BRIDGES

The scaled one-span bridge model of a six-span Reinforced Concrete Arch Bridge that has been in service for more than 30 years was fabricated using organic glass.Considering the different constraint conditions of continuous and segmental decks,static and dynamic tests were performed respectively in laboratory.The effects of the constraint condition on the mechanical property of the bridge are discussed.It is shown that the constraint of the deck has a significant effect on the structural stiffness(the stronger the constraint,the higher the structural frequency).It is indicated that the horizontal dynamic characteristic is more sensitive to the constraint of the deck than the vertical dynamic characteristic,and the constraint condition in the middle of the deck has a great effect on the structural frequency.The variation tendency of the static mechanical property with the constraint of the bridge deck is also obtained.Comparing with the field monitoring data,the reliable bridge model that can well reflect the actual mechanical properties of the original structural is obtained.