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为了解160 000 m3大型液化天然气(LNG)储罐混凝土外罐在施工期间的抗裂性能,避免由于水泥水化放热、混凝土收缩、外界气温变化而造成的外罐墙壁竖向开裂及扶壁柱局部环向裂缝现象,运用有限元数值模拟技术,采用增量法,分别探讨了施工模板材料、施工质量、施工季节及混凝土入模温度对混凝土外罐温度应力分布的影响及其规律.结果显示:模板对温度应力的影响作用较小,混凝土收缩导致混凝土拉应力持续增长,温度应力随着施工季节温度的变化而产生相应波动,施工质量及施工季节对温度应力的影响较大;在上述结论基础上,视温度应力结果为水化热、混凝土收缩、外界气温及入模温度各自单一影响作用下温度应力的叠加,进而总结出各因素对混凝土施工阶段温度应力的影响规律,并提出可供实际工程参考的防裂措施建议.
In order to understand the anti-cracking performance of 160,000 m3 large LNG storage tank concrete during construction period, avoid the vertical cracking of the outer tank wall due to the hydration of cement hydration, shrinkage of concrete and changes of outside air temperature Column circumferential crack phenomenon, the use of finite element numerical simulation technology, incremental method, respectively, to discuss the construction template materials, construction quality, construction season and the temperature of concrete mold temperature stress distribution of concrete outer shell and its regularity.Results The results show that the influence of the template on the thermal stress is small, the concrete tensile stress increases continuously due to the shrinkage of the concrete, the temperature stress fluctuates with the change of the construction season temperature, and the construction quality and the construction season have a greater impact on the thermal stress. Based on the conclusion, the temperature stress depends on the superposition of temperature stress under the single influence of hydration heat, concrete shrinkage, external air temperature and mold temperature, and then summarizes the influence of various factors on the temperature stress in concrete construction stage. Proposals for crack prevention measures for actual project reference.