Study on Initial Defects of Concrete Structures Generated during the Construction Process

混凝土结构施工过程中产生的初始缺陷研究

• 批准号: 59850080
• 负责人: TANABE Tada-aki
• 金额: $ 4.1万
• 依托单位: Nagoya University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Developmental Scientific Research
• 财政年份: 1984
• 资助国家: 日本
• 起止时间: 1984 至 1985
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-59850080/
• 关键词: Initial defects; Thermal stress; FEM analysis; Compensation line; Compensation plane; ひびわれ巾; クーリング; 入口温度

The study aims at in the first place estimating the amount of initial defects, specially the thermal residual stress or the width of crackings due to it and in the second place to estimate the effect of those defects on the ultimate strength of the structure. The experiment using a large scale mass concrete specimen was carried out and it is recognized that the thermal deformation occurs not only to the horizontal direction but to the vertical direction as well which are decomposed into the axial deformation and the bending deformation similarly to the ordinary beam deformation under the axial load and bending moment.The FEM programs to give the residual thermal stress are developed, i.e. 3-D and 2-D isoparametric FEM programs and finite prism element program. For the purpose of the simple design conveniency, the compensation line and plane methods, the accuracy of which are almost comparable to the FEM analysis are proposed.The effects of the initial defects on the ultimate strength of concrete structures were calculated using the elastic plastic analysis and it was recognized that the reduction of the ultimate strength sometimes exceeds the 20 percent of the initial strength.

这项研究的目的是首先估计初始缺陷的数量，特别是热残余应力或裂纹的宽度，由于它，并在第二个地方，以估计这些缺陷对结构的极限强度的影响。通过对大体积混凝土试件的试验研究，发现在轴向荷载和弯矩作用下，混凝土构件不仅在水平方向上发生温度变形，而且在垂直方向上也发生温度变形，并将温度变形分解为轴向变形和弯曲变形，这与普通梁的变形类似，编制了计算残余温度应力的有限元程序，即三维、二维等参有限元程序和有限棱柱体单元程序。为了简化设计计算，提出了与有限元分析精度相当的补偿线法和补偿平面法，并采用弹塑性分析方法计算了初始缺陷对混凝土结构极限强度的影响，发现初始缺陷对混凝土结构极限强度的影响有时超过初始强度的20%。

项目成果

Trans.of JCI. Vol-6. (1984)

JCI 翻译。

Proc.of 【I】st EASEC. Vol-2. (1986)

[I]st EASEC 论文集（1986 年）。

第2回マスコンクリートコロキウム論文集. (1984)

第二届大体积混凝土研讨会论文集（1984 年）。

Proc. of 2nd Colloquium on Thermal Stress Generation in Massive Concrete Structures. (1984)

过程。

Proc. of 1st EASEC. Vol. 2. (1986)

过程。