Reinforcement Detailing for Local Cracking

局部裂缝的加固细节

• 批准号: 02650336
• 负责人: YAMAZAKI Jun
• 金额: $ 1.15万
• 依托单位: Nihon University (1991)Tokyo Metropolitan University (1990)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1990
• 资助国家: 日本
• 起止时间: 1990 至 1991
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-02650336/
• 关键词: Cracking; Reinforcement; Stress intensity factor; Finite element analysis; 有限要素

A crack in concrete dominant in lightly reinforced area tends to develop unstably and progressively in cases of beams subjected to shear, temperature change and drying shrinkage of slabs and walls, or anchor pull-out. Methods are not established for computation to predict propagation of such cracks, and consequently, theory is insufficient for reinforcement detailing.A method for computational simulations were developed for application to various behaviors using an assumption that a criteria for crack propagation is determined by stress intensity factors of linear fracture mechanics, and using finite element analysis.The method was found to be reasonably capable of simulating propagations of cracks in cases of : diagonal tension cracking in beams subjected to shear, cracking in anchor pull-out, and discrete cracking in slabs due to shrinkage where reinforcement restrained crack opening to a certain degree.Characteristic values for the stress intensity factors for propagating cracks are not established for each behaviors studied. Because of that, accuracies are not satisfactory in predicting external loads to propagate cracks at various stages up to strubtural failure. The method was found helpful for predicting distribution and paths of crack developments for the cases studied. Thus the method was deemed helpful for detailing reinforcement.

在梁受剪力、温度变化、板墙干缩或锚杆拔出的情况下，以轻配筋为主的混凝土中的裂缝往往会不稳定地逐步发展。基于线性断裂力学的应力强度因子是由线性断裂力学的应力强度因子决定的，并利用有限元分析，提出了一种适用于各种行为的计算模拟方法。该方法被发现能够合理地模拟受剪梁的斜拉裂、锚固拔出的裂缝以及板的收缩引起的离散裂缝的情况，其中钢筋将裂缝张开限制到一定程度。正因为如此，预测外载荷在结构破坏的不同阶段扩展裂纹的精度并不令人满意。结果表明，该方法有助于预测所研究实例的裂缝分布和发展路径。因此，这种方法被认为有助于详述钢筋。

项目成果

Terashima, Y., Yazawa, E., Nagashima, F. and Yamazaki, J.: ""Numerical Simulation of Anchor Pull-out from Concrete"" Proceedings of the Japan Concrete Institute. 91-96

Terashima, Y.、Yazawa, E.、Nagashima, F. 和 Yamazaki, J.：““锚杆从混凝土中拔出的数值模拟””日本混凝土学会会议录。

寺島,矢沢,長島,山崎: "埋込みアンカ-部引抜きによる コンクリ-トひびわれの進展解析" コンクリ-ト工学初次論文報告集. 13. 91-96 (1991)

Terashima、Yazawa、Nagashima、Yamazaki：“通过拉出嵌入锚杆来分析混凝土裂缝的增长”混凝土工程第一篇论文报告 13. 91-96 (1991)

寺島・矢沢・長島・山崎: "表面ひびわれの面内進展への鉄筋の抑制" コンクリ-ト構造物の体積変化によるひびわれ幅制御に関するコロキウム論文集(JCIーC21). 141-148 (1990)

Terashima、Yazawa、Nagashima、Yamazaki：“钢筋对表面裂纹平面内扩展的抑制”通过混凝土结构体积变化控制裂纹宽度学术讨论会论文集 (JCI-C21) 141-148 (1990)。

矢沢,寺島,山崎: "アンカ-の引抜きによるひびわれのひとつの解析評価手法" コンクリ-ト工学年次論文報告集. 13. 85-90 (1991)

矢泽、寺岛、山崎：“一种分析和评价因拔锚引起的裂缝的方法”混凝土工程年论文报告13. 85-90（1991）

Yamazaki, J., Yazawa, E., and Terashima, Y.: ""Model for the Behavior of Surface Crack and for Its Restraint by Reinforcement"" Proceedings of JCI Colloquium on Control of Crack Width Caused by Volume Change of Concrete in Massive Concrete Structures, Jap

Yamazaki, J.、Yazawa, E. 和 Terashima, Y.：“表面裂缝行为模型及其通过钢筋的抑制”JCI 大规模混凝土体积变化引起的裂缝宽度控制学术讨论会论文集