混凝土收缩徐变对高层混合结构的影响及对策  

Influence of Creep and Shrinkage on Tall Hybrid Structures and Its Countermeasures

作　　者：沈蒲生[1] 方辉[1] 夏心红[1] 

机构地区：[1]湖南大学土木工程学院,湖南长沙410082

出　　处：《湖南大学学报（自然科学版）》2008年第1期1-5,共5页Journal of Hunan University:Natural Sciences

基　　金：国家自然科学基金资助项目(50378035)

摘　　要：针对高层混合结构竖向变形差的计算与工程对策问题进行了研究.首先,给出了超高层混合结构竖向变形差的计算方法.在结构分析中,采用刚度逐层形成、荷载逐层施加的方法考虑施工过程的影响;根据ACI规范混凝土徐变收缩计算公式,假设构件荷载线性增加,引入平均龄期影响系数和平均持荷影响系数计算变荷载作用下混凝土的徐变和收缩.用龄期调整的有效模量法分析了构件配筋率对构件徐变的影响.分析中还考虑了核心筒超前施工的影响.然后,通过算例分析,给出了减小混合结构竖向变形差的工程对策.该法简单实用,可以在超高层混合结构设计中计算竖向变形差时使用.This paper aims to research the different vertical displacements in tall hybrid-structures and the corresponding engineering measures. First, the method to calculate the different vertical displacements in tall hybrid-structures was presented. This method took into account the effects of construction process by applying loads sequentially story by story. Based on the concrete creep and shrinkage calculation formula in American Concrete Institute （ACI） code, with the assumption that loads were increased linearly in members, creep and shrinkage effects of members were analyzed by adopting two parameters named average load-aged coefficient and average age-last coefficient. Effects of steel ratio on members creep were analyzed by age-adjusted module method （AEMM）. The effects that core-tube was constructed in advance to outer steel frame were also considered. Then, based on the sample calculation, the measures to effectively reduce different vertical displacements in hybrid-structures were proposed. This method is simple and practical in the calculation of different vertical displacements in tall and super-tall hybrid-structures.

关 键 词：徐变 收缩 施工过程 混合结构 

分 类 号：TU973.256[建筑科学—结构工程]