温度变化对预应力混凝土曲线梁桥的影响研究

Influence of Temperature to Prestressing Concrete Curved Girder Bridge

依托某城市快速化改造中曲率半径为60m的预应力混凝土曲线梁桥制作1∶5缩尺模型,利用振弦式锚索测力计、压力传感器和自动化无线数据采集系统,测量温度变化对有效预应力波动以及支座反力的影响;通过有限元软件计算预应力波动对支座反力变化的影响。结果表明,有效预应力随温度变化的趋势明显且相关性好,说明测量数据可靠,温度越低,有效预应力越大;温度变化引起的支座反力改变主要是因为混凝土结构自身的热胀冷缩,而由于温度变化造成的有效预应力波动引起的支座反力改变很小,约占5%~10%的比例。

Based on a curved bridge of 60 meters radius in the rapid transformation of one city, a model with the scale ratio of 1 ： 5 is produced, detailed analysis of the temperature to the prestressing load and the change of support reaction to the curved girder bridge are made by using pulling force measurement of anchor rope, pressure sensor and automation data acquisition instrument. The ratio of the support reaction change caused by the variation of the prestressing load is calculated. The results show that temperature has a certain influence on the prestressing load, the lower the temperature, the greater the prestressing load the change of the support reaction caused by temperature mostly because of the thermal expansion and contraction of concrete, but the change of the prestressing load is very little, just account for about 5% to 10%.