施工期钢筋混凝土结构是由材料性能不断变化的混凝土构件以及临时支撑组成的时变结构。在楼板的养护过程中,各层楼板承担的荷载会发生重新分配现象,但理论上对其产生的原因一直没有合理的解释。在结构特征参数方法和徐变理论的基础上分析了考虑混凝土徐变效应的的荷载传递规律,探讨了徐变造成荷载重分配的机理并证明了徐变是产生施工期混凝土结构荷载重分配现象的原因之一。同时讨论了在常用施工方案下,徐变效应对结构最大荷载的影响程度以及结构最大荷载的分布范围。通过比较发现徐变能够降低结构的最大荷载,有利于施工期结构安全。施工期混凝土结构的安全性验算可以参照本文的结果考虑徐变的有利影响。
Reinforced concrete structures during construction consist of concrete dements with changing material properties and the temporary supporting system. During slab curing stage, load re-distribution has been observed. However, theoretical explanation of this redistribution has not been reported. Creep effects on load distribution are analyzed in this paper, based on the structural characteristic parameter method and the creep theory. It is testified that creep is one of the reasons leading to load re-distribution between slabs during the slab curing stage. Creep effects on maximum slab load and the range of maximum slab load are discussed for commonly used construction schemes. It is found that creep can reduce the maximum slab load in reinforced concrete structures during construction. To assure safe and economical construction of reinforced concrete structures, results in this paper may be used to consider the beneficial effects of creep.