钢筋混凝土框架结构伸缩缝间距计算

资料大小：190KB
资料类型：.PDF
资料等级：
发布时间：2021-09-13

资料介绍

钢筋混凝土框架结构伸缩缝间距计算
李富民1, 孟少平2
(1. 中国矿业大学建筑工程学院, 江苏徐州　221008;
2. 东南大学土木工程学院, 江苏南京　210096)
摘要: 《混凝土结构设计规范》给出的钢筋混凝土框架结构中伸缩缝间距取值比较原则化, 因而
其应用效果不尽人意. 为此, 提出伸缩缝间距应能保证温度及收缩应力不大于容许应力, 且使综
合裂缝宽度处于规范允许范围内的思想1 以此为基础, 对由多层简化为单层的规则框架中跨梁
板截面考虑徐变和开裂影响的平均轴拉应力进行了验算, 并从中推导出与温度及收缩自由应变、
结构约束、截面配筋率、荷载标准组合下的钢筋应力等主要因素有关的伸缩缝间距计算公式. 算
例表明公式具有一定的合理性和参考价值.
关键词: 框架结构; 温度及收缩; 结构约束; 裂缝; 伸缩缝; 容许应力; 配筋率
中图分类号: TU 375　　文献标识码: A
Calcu lat ing of Expan sion Jo in t Spacing of
Reinfo rced Concrete F rame St ructu res
L I Fu2m in1, M EN G Shao2p ing2
(1. Co llege of A rch itecture and Civil Engineering, Ch ina U niversity ofM ining & Techno logy,
Xuzhou, J iangsu 221008, Ch ina;
2. Co llege of Civil Engineering, Southeast U niversity, N anjing, J iangsu 210096, Ch ina)
Abstract: The values of expan sion jo in t spacing of reinfo rced concrete st ructu res are given by
som e standards. Bu t the effect of u sing these values is no t very saf isfacto ry. To f ind the
reasonab le values it is necessary to take accoun t of two facto rs: 1) the st resses cau sed by
temperatu re and sh rinkage are less than the allow ab le st resses; 2) the compo site crack ing
w idth has to be w ith in the allow ab le range. O n the basis of the above2nam ed analysis the
average ten sion st resses w ith including the effect of creep and crack ing w ere exam ined in the
m iddle sect ion s of regu lar single layer f ram e simp lif ied f rom m u lt ilayer f ram e. By the
exam in ing a fo rm u la calcu lat ing the expan sion jo in t spacing of reinfo rced concrete f ram e
st ructu res w as deduced. In the fo rm u la the severalm ain facto rs, such as the f ree st rain induced
by temperatu re and sh rinkage, st ructu re rest rain ing, steel rat io of cro ss sect ion and the
characterist ic com b inat ion st ress in reinfo rcem en t s, w ere taken in to con siderat ion. Two
calcu lat ing examp les indicate that the fo rm u la is rat ional and u sab le.
Key words: f ram e st ructu res; temperatu re and sh rinkage; st ructu re rest rain ing; crack ing;
expan sion jo in t s; allow ab le st ress; steel rat io
近年来, 混凝土结构在温度及收缩作用下的开
裂问题受到各国学者的广泛关注[ 123 ] , 各种有关的
裂缝控制措施也得到了不断的研究和发展[ 429 ]. 伸
缩缝作为控制结构温度及收缩裂缝的传统措施, 若
在合理设置其间距的条件下, 是可以有效控制温
度及收缩裂缝的, 但由于我国《混凝土结构设计规