考虑收缩徐变的施工分析对528m超高层塔楼巨柱类型选择的影响
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摘要
相较于型钢混凝土(SRC)巨柱,钢管混凝土(CFT)巨柱具有极小的收缩效应的特点,同时徐变变形也相应偏小。以南宁东盟塔的设计实践为例,通过进行考虑时间相关的混凝土收缩徐变的非线性施工分析,对采用不同巨柱类型的塔楼施工变形补偿进行了预测。塔楼混凝土核心筒和外框柱随时间变化的弹性变形、收缩变形和徐变变形根据GL2000收缩徐变模型进行计算。分析方法为设计团队自行开发的程序与ETABS(2015版)相结合的形式。通过该方法,带外伸桁架的巨柱超高层结构的施工完毕后的核心筒及巨柱的内力随时间的变化趋势被预测出来,另外,外框与核心筒之间的随时间变化的相对变形也被计算预测出来。这些结果对采用SRC巨柱和CFT巨柱的不同结构方案的不同构件的加强措施提供了重要依据。
Compared with steel reinforced concrete( SRC) mega columns,concrete-filled-tube( CFT) mega columns only have minimal shrinkage effect,and creep effect is appropriately less.Per the practice as Nanning ASEAN Tower,time dependent creep and shrinkage nonlinear construction sequence analysis was studied to predict the construction deformation compensation of the tower in term of different mega column types.The time dependent elastic deformation,shrinkage deformation and creep deformation of concrete core and perimeter frame columns of the tower are calculated based on GL2000 creep and shrinkage model.The analysis is performed by combining the self-developed program of design team and ETABS V2015.The time dependent force changes at central core and mega columns after the construction completion were predicted in term of this approach,in additional,the time dependent differential shortenings between core and perimeter frame were figured out.These results are the important criteria of the different enhancement measures of structural components for the different structural system with SRC mega column and CFT column respectively.
Compared with steel reinforced concrete( SRC) mega columns,concrete-filled-tube( CFT) mega columns only have minimal shrinkage effect,and creep effect is appropriately less.Per the practice as Nanning ASEAN Tower,time dependent creep and shrinkage nonlinear construction sequence analysis was studied to predict the construction deformation compensation of the tower in term of different mega column types.The time dependent elastic deformation,shrinkage deformation and creep deformation of concrete core and perimeter frame columns of the tower are calculated based on GL2000 creep and shrinkage model.The analysis is performed by combining the self-developed program of design team and ETABS V2015.The time dependent force changes at central core and mega columns after the construction completion were predicted in term of this approach,in additional,the time dependent differential shortenings between core and perimeter frame were figured out.These results are the important criteria of the different enhancement measures of structural components for the different structural system with SRC mega column and CFT column respectively.
引文
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[5]刘枫,刘军进.混凝土收缩徐变对天津津塔施工模拟及预变形的影响分析[J].建筑结构,2012,42(9):142-145.
[6]郭彦林,江磊鑫,刘学武,等.广州珠江新城西塔施工过程内外筒竖向变形差值研究[J].施工技术,2008,37(增刊):5-8.
[2]BAKER W F,KORISTA D S,NOVAK L C.Buri Dubai:Engineering the world’s tallest building[J].The Structural Design of Tall and Special Buildings,2007,16(4):361-375.
[3]NAGUIB W,MIRMIRAN A.Creep modeling for concrete-filled steel tubes[J].Journal of Constructional Steel Research,2003,59(11):1327-1344.
[4]刘军进,徐自国,徐强,等.天津津塔施工过程分析及预变形技术[J].建筑结构,2012,42(9):137-141.
[5]刘枫,刘军进.混凝土收缩徐变对天津津塔施工模拟及预变形的影响分析[J].建筑结构,2012,42(9):142-145.
[6]郭彦林,江磊鑫,刘学武,等.广州珠江新城西塔施工过程内外筒竖向变形差值研究[J].施工技术,2008,37(增刊):5-8.