弘德大桥大体积混凝土承台施工期温控研究

Study on Temperature Control in Construction Period of Mass Concrete Base Slab for Hongde Bridge

摘要:

以弘德大桥承台施工为例，采用有限元桥梁软件MIDAS Civil，对大体积混凝土承台在施工期的温度场和应力场进行计算仿真模拟，以期为今后大体积混凝土工程的温控防裂提供参考。结果表明，承台混凝土层在浇筑结束后42 h左右达到温度峰值63.4 ℃，布置冷却水管有利于加快内部散热；升温阶段的最大主拉应力分布在冷却水管周围，降温阶段初期的最大主拉应力出现在顶面棱边附近，降温阶段后期的最大主拉应力出现在长边中心附近。

Abstract:

In order to provide a reference for temperature control and crack prevention of mass concrete projects in the future, and taking the construction of base slab for Hongde Bridge as an example, the finite element bridge software MIDAS Civil is used to calculate and simulate the temperature field and stress field in the construction period of mass concrete base slabs. The results show that the concrete layer of the base slab reaches a peak temperature of 63.4 ℃ about 42 hours after the pouring, and the layout of cooling water pipe is beneficial to accelerating the internal heat dissipation. The maximum principal tensile stress during the heating stage is distributed around the cooling water pipes. At the beginning of the cooling stage, the maximum principal tensile stress occurs near the top edge. In the later stage of the cooling stage, the maximum principal tensile stress appears near the center of the long side.