脱粘对钢管混凝土拱温度应力及内力影响分析

Influence of Debonding on Thermal Stress and Internal Force of Concrete Filled Steel Arch

选取钢管混凝土单圆管拱、哑铃型拱和桁拱3座桥例为工程背景,结合有限元法,分析脱粘对温度应力及内力的影响.研究结果表明:脱粘使得夏季的平均温度降低,冬季的平均温度升高,但总体上脱粘与无脱粘的平均温度相差很小;脱粘使得钢管的温度自应力增大,核心混凝土的温度自应力减小,且超过拱肋自重产生的应力,因此钢管混凝土拱桥温度应力的计算要考虑脱粘的影响.此外,脱粘对钢管混凝土单圆管拱、哑铃形拱的温度内力基本上没有影响,对桁肋拱的温度内力有较大的影响.

Three concrete filled steel tube （CFST） arch bridges were studied by finite element method, to investigate the influence of debonding on thermal stress and internal force. The analysis result shows that comparing with non-debond- ing, debonding decreases average temperature of arch rib section in summer, and increases the temperature in winter, but average temperature difference between debonding and non-debonding is slightion debonding increases the thermal stress of steel, decreases the stress of the core concrete, the debonding stress variation is greater than the gravity stress, therefore the influence of debonding should be considered in thermal stress calculation of CFST arch bridge. Debonding has little in- fluence on internal thermal force of CFST arch with singular or dumbbell section, has significant influence on internal thermal force of CFST truss arch.