钢管混凝土拱计算合龙温度试验研究

Experimental research on calculated closure temperature of concrete filled steel tubular arch bridge

对钢管混凝土拱肋成型过程混凝土水化热作用下的结构温度场和温度效应进行了连续的试验观测。试验采用单圆管截面的钢管混凝土拱肋进行测试,完成了从空钢管合龙至形成钢管混凝土拱肋的过程。在试验实测数据的基础上论述了钢管混凝土拱肋成型过程中的结构温度场和温度效应变化规律,并讨论了钢管混凝土拱桥计算合龙温度的确定方法。试验及分析结果表明,水化热对拱肋成型后钢管的残余温度应力影响很小,而对混凝土的残余温度应力有较大影响;在确定钢管混凝土拱的计算合龙温度时,可以将管内混凝土浇注后7 d的大气平均温度作为拱肋成型时的结构温度,取水化热结束后的结构残余温度内力作为对应的截面温度内力进行计算。

Experiment about temperature difference effect on the circular concrete filled steel tubular （CFST） arch rib was carried out. According to the continuous observation on temperature field and temperature effect on a concrete filled steel tubular arch rib during its forming, the temperature field and temperature effect, as well as their variation were discussed based on measured data. The definite method of the calculated closure temperature of CFST arch bridge was also discussed. Results show that there is little remaining thermal stress on the steel tubular due to hydration heat, while the heat has much influence on the concrete. The average temperature of 7days after the concrete is filled in the tube and the remaining thermal internal forces after the hydration heat disappear are used to calculate closure temperature of CFST arch bridge.