摘要
针对箱梁截面非均匀收缩现象开展了模型试验研究,试验中考虑了混凝土配合比及理论厚度等因素。采用以非线性湿度扩散理论为基础的的有限元分析方法,对试验模型进行了仿真分析。试验结果及理论分析均表明:混凝土箱型截面不均匀收缩现象是显著的,模型截面上、下缘应变差占轴向收缩应变的13%～18%;造成混凝土截面不均匀收缩的原因是截面各部位厚度存在差异,使得内湿度变化率不同,在收缩过程中截面各部位存在变形差,导致结构在发生轴向收缩的同时,还将发生挠曲变形。
According to the non-uniform shrinkage phenomenon of the box girder section,the model experiment was made and different concrete mix proportions and nominal depths were considered.Based on the nonlinear moisture diffusion theory,a finite element model was established for the specimens.The test and theoretical analysis results show that the phenomenon of non-uniform shrinkage of box section is obvious and the differential shrinkage value between top and bottom of the section is 13% to 18% of the axial shrinkage.The different top web and bottom slab thicknesses of the concrete box girder section are the reason for non-uniform shrinkage deformations,which lead to different relative humidities in the concrete box girder section and differential deformation existed in the individual parts of section.Accordingly,it will produce not only axial shrinkage of the cross section but also deflection.
出处
《中国公路学报》
EI
CAS
CSCD
北大核心
2010年第3期64-69,共6页
China Journal of Highway and Transport
基金
国家西部交通建设科技项目(200431881426)
关键词
桥梁工程
混凝土结构
非线性湿度扩散理论
非均匀收缩
bridge engineering
concrete structure
nonlinear moisture diffusion theory
non-uniform shrinkage
