宽幅混凝土箱梁的横向收缩应变差分析
Analysis of Transverse Shrinkage Strain Differences of Wide Concrete Box Girder
龚勇 1程涛1
作者信息
- 1. 中交第二公路勘察设计研究院有限公司,湖北武汉430056
- 折叠
摘要
为了研究施工过程中宽幅混凝土箱梁的收缩应变差对梁体应力的影响,以常平5号高架桥(跨径6×30 m,全宽33.5m的整幅预应力混凝土连续箱梁桥)为背景,依照文献公式计算各施工节段间及箱梁各部位间的收缩应变差,再转换成等量温差施加于空间块体元模型上,重点分析了箱梁节段龄期差和各部位不均匀收缩应变差引起的收缩效应及箱梁各部位的应力分布情况.分析结果表明,单纯的箱梁不同结构部位不均匀收缩应变差引起的拉应力不会引起箱梁开裂;收缩应力主要与节段龄期差有关,节段龄期差引起的箱梁施工节段间的收缩应变差引起的收缩应力则可能使梁体开裂.
Abstract
To study the influence of the shrinkage strain differences of wide concrete box girder on the stress of the girder in the construction,the Changping Viaduct No.5 (a prestressed concrete continuous box girder bridge with span arrangement 6 × 30 m and full deck width 33.5 m) was cited as an example.In terms of the relevant formulae in the literatures,the shrinkage strain differences between the constructed segments and between the different parts of the girder were calculated,the calculated strain differences were then converted into the equivalent temperature differences and applied to the spatial block element model.The shrinkage effect and stress distribution of the different parts of the girder caused by the segment age differences and the nonuniform shrinkage strain differences of the different parts were particularly analyzed.The results of the analysis demonstrate that the tensile stress caused by the non-uniform shrinkage strain differences of the different parts of pure box girder will not cause cracking in the girder.The shrinkage stress is mainly related to the constructed segment age differences while the shrinkage stress caused by the shrinkage strain differences between the segments of the girder due to the segment age differences will possibly cause the cracking in the girder.
关键词
宽幅箱梁/混凝土/横向收缩/收缩应变/龄期差/当量温差/有限元法Key words
wide box girder/concrete/transverse shrinkage/shrinkage strain/age difference/equivalent temperature difference/finite element method引用本文复制引用
出版年
2013
NETL
NSTL
维普
万方数据