苏通大桥辅桥箱梁节段水化热效应的仿真分析

Simulation of Hydration Heat Effects on the Box Girder Segments of the Auxiliary Bridge for Sutong Bridge

结合实际工程,分析了大体积混凝土水化热是使其表面产生裂缝的主要原因之一。采用三维瞬态温度场理论,利用有限元程序ANSYS对苏通大桥连续刚构墩顶现浇块的水化热效应进行了数值模拟,分析了箱梁水化热温度场和应力场的分布规律。结果表明,水化热引起的温度应力使底板内外表面受拉,混凝土内部受压,这样的温度应力是自平衡的。水化热效应引起的早期温度应力是不容忽视的,提出了控制水化热温度及温度应力的合理建议,有一定的工程参考价值。

As one of the reasons bring on cracks, hydration heat of massive concrete is analyzed according to a practical project. Based on the theory of three-dimensional transient temperature field and the general finite element program ANSYS, the hydration heat effects on the cast-in-place segments on the pier top of the continuous rigid-frame of Sutong Bridge is simulated, including the distribution of temperature field and thermal stress field. The analysis results indicate that the inner and outer surfaces of the bottom slab are tensile and the inside of the slab is under compression because of thermal stress caused by hydration heat. These thennal stresses are self-balanced. Early thermal stress shouldn＇ t be neglected. In the end, some reasonable methods are presented for controlling the early hydration temperature and its thermal stress and these measures are worthy of being consult for analogous works.