沪通长江大桥承台大体积混凝土动态设计养护技术研究

沪通铁路沪通长江大桥为公铁两用桥,针对沪通长江大桥北岸正桥主墩承台平面尺寸大、混凝土数量多的工程特点,进行大体积混凝土温控方案设计,计算承台大体积混凝土的内部温度场及仿真应力场,并根据计算结果制定出控制有害温度裂缝的温控标准和相应的温控措施,提出"动态设计养护"法。施工实践表明,设计混凝土最优养护曲线,适时动态调整养护措施,可有效控制承台大体积混凝土裂缝。

Study on Dynamic Curing Design of Pile Cap Massive Concrete of Shanghai-Nantong Yangtze River Bridge

Shanghai- Nantong Yangtze River Bridge on Hu-Tong Railway is a combined highway and railway bridge. In the light of characteristics of massive concrete of main span pile cap of Hu-Tong Yangtze River Bridge, temperature control scheme for massive concrete is designed and internal temperature field and simulation stress field are calculated with finite element analysis. Based on calculation results,temperature control standards and measures for preventing harmful cracks are put forward. At the same time,the method of dynamic curing design is presented. Designing optimal concrete curing curve and timely adjusting maintenance measures are effective in controlling cracks of pile cap massive concrete.