基于断裂理论的在役钢筋混凝土桥梁疲劳损伤机理研究

项目名称： 基于断裂理论的在役钢筋混凝土桥梁疲劳损伤机理研究

项目编号： No.51308156

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 建筑科学

项目作者： 孙永明

作者单位： 哈尔滨工业大学

项目金额： 25万元

中文摘要： 混凝土桥梁占国内桥梁总数的90%以上，普遍处于长期超载运营状态、存在较重的安全隐患，是现阶段国内桥梁管养工作的重点；而现有混凝土桥梁安全评定方法没能抓住结构疲劳破坏的本质，其检测内容和评定指标均不能有效反映结构的疲劳状态，造成了近五年内混凝土桥梁脆性坍塌事故屡见不鲜，甚至出现混凝土桥梁在加固后几年内仍发生脆性坍塌的案例。鉴于此，本项目以钢筋混凝土桥梁为突破口，基于断裂理论展开对混凝土桥梁疲劳损伤机理深入研究。重点研究混凝土内部裂纹状态在疲劳荷载作用下的扩展过程，分析裂纹总体分布和主裂纹扩展状态对混凝土疲劳性能的影响；研究开裂截面处钢混粘结面疲劳滑移性能，分析钢筋滑移长度对梁体疲劳性能的影响；并提出基于疲劳状态的混凝土桥梁安全评定方法。本项目的研究成果将在基础理论层面上，对国内日趋严峻混凝土桥梁管养工作起到推动作用，具有重大的现实意义和经济价值。

中文关键词： 安全评定；桥梁工程；混凝土疲劳；钢筋滑移；损伤机理

英文摘要： Concrete bridges account for more than 90% of the total number of domestic bridges, most of them are gengrally at a long-term overload operation state and have seriously hidden danger, whick are the working emphasis of domestic bridge maintenance management in this stage. The existing concrete bridge assessment method failed to grasp the nature of structural fatigue damage, the test content and assessment indicators can not effectively reflect the structure fatigue state, which result in a brittle collapse of the concrete bridge in the past five years are common, even some concrete bridges still brittle collapse in a few years after reinforcement. In view of this, the project makes the reinforced concrete bridge as a breakthrough, further study the fatigue damage mechanism of concrete bridges based on the fracture theory. Study the expansion process of the internal cracks of concrete under fatigue loading, analyze the affections of all cracks general distribution and main cracks propagation to the concrete fatigue property. Study the fatigue slipping performance of the interface between steel-bar and concrete at splitting section, analyze the impact of the slipping length on the beam fatigue performance. Propose a concrete bridge safety assessment method based on fatigue state. The achievements of this paper wil

英文关键词： safety assessment；bridge engineering； concrete fatigue；steel-bar slippage；damage mechanism