滑动层对上部基础施工温度应力影响的有限元分析及应变监测研究

TEMPERATURE STRESS FINITE ELEMENT ANALYSIS AND STUDY ON STRAIN MONITORING AT MASS CONCRETE BASE SLAB WITH SLIDING LAYER

工程实践中,滑动层合理设置对减少大体积混凝土施工裂缝有着不可估量的作用,核电站安全壳基础设置防水层兼做滑动层也不例外。影响混凝土施工裂缝的因素很多,但根本且直接原因还是温度应力、收缩应力水准和抗裂措施的问题。影响施工应力水准的因素同样很多,如混凝土基础浇筑的体量、基础形式、混凝土用胶凝材料水化热大小及水化速率、养护措施以及滑动层的滑动能力等等。正是基于核电站安全壳基础的施工研究,建立滑动层及整体结构的有限单元模型,开展滑动层对上部结构的温度应力有限元分析,同时进行混凝土浇筑过程中的应变监测研究。理论分析结果表明:滑动层滑动能力对混凝土温度应力水准有直接的贡献作用,同时通过实测与理论结果对比分析,能为滑动层的滑动能力特性建立量化模型,为批量化的CPR1000核电工程基础或类似工程理论分析提供可行的方法和经验参考。

There is an inestimable role in a reasonable sliding layer for reducing cracks in mass concrete construction. Actually, many factors have an impact on cracks in concrete construction, but the fundamental and direct causes are temperature stress level and anti-crack measures. There are also many factors to generate different stress level, such as the size and the form of poured concrete foundation, hydration heat and rate of cementitious materials, curing measures, as well as the sliding ability of the sliding layer and so on. In this paper, the finite element models of the sliding layer and the overall structure are built, finite element analysis of temperature stress on upper structure with a sliding layer and strain-monitoring are carried out. The results from the theoretical analysis show that the sliding ability has a direct impact on the level of temperature stress, at the same time, according to results of the test and theoretical analysis, this paper has given quantitative models of the sliding characteristics, which provides practical methods and experience for the theoretical analysis for the batch CPR1000 nuclear power project or similar projects.