钢管混凝土哑铃形拱的计算温度取值研究

Study on thermal calculation magnitude of concrete filled steel tube arch bridge with dumbbell cross section

以经实桥实测温度场验证的有限元方法,以一座钢管混凝土哑铃形肋拱为基本分析对象,对其计算合拢温度、有效温度和平均温度内力进行了计算分析.研究结果表明,钢管混凝土哑铃形拱的计算合拢温度取值主要应考虑浇筑混凝土后28 d的平均气温与哑铃形弦管管径;最高有效温度与当地最高气温相近,最低有效温度与当地最低日平均气温相近.论文还给出了钢管混凝土哑铃形拱在福建不同地区的最高、最低有效温度建议值,并对JTG D60-2004规程的温度取值进行了讨论.

Using finite element method verified by field temperature test of a bridge, the calculated closure temperature, maximum and minimum effective temperatures and temperature forces are studied by taking a CFST arch bridge with dumbbell shaped ribs as a case study. Research results show that for CFST arch with dumbbell shaped section, the average of the ambient temperature of the 28 d after the concrete filled into the tube and the diameter of the steel tube in the section are the two major factors which should be taken into account in calculated closure temperature; the maximum effective tem- perature of the rib is close to local maximum temperature and the minimum effective temperature is close to local minimum daily average temperature. A suggestion for maximum and minimum effective temperature of CFST arch bridge with dumbbell shaped section in variation areas of Fujian Province is proposed and the thermal load specification in Code JTG 1360 -2004 is discussed.