论文部分内容阅读
服役多年实桥的真实承载能力和极限状态下的力学行为一直是研究人员关心的问题,但由于实桥破坏性试验实施困难,这方面的研究进展有限。该文对湖南省宁乡县一座服役43年的钢筋混凝土简支T梁桥实施了破坏性试验,考察了试验桥梁的全过程受力性能以及极限状态下的结构反应。首先对试验桥梁的材料强度、结构损伤及退化等进行了详细调查,试验中采用2个5000kN千斤顶对桥梁进行加载直至结构破坏,在此基础上进行有限元分析并与试验结果进行比较。试验结果表明:由于整体连接、边界条件、初始损伤等因素影响,试验实桥的受力性能表现出了结构模型与有限元分析不具有的局部非线性,但考虑了材料退化的有限元分析结果与试验结果呈现一定程度吻合;试验桥破坏形式为受拉钢筋屈服然后混凝土压碎的典型受弯结构破坏,除顶部混凝土压碎外桥梁支座等部位也出现了破坏迹象,表明实桥的破坏形式可能由多个因素控制。
The actual bearing capacity and the mechanical behavior at the ultimate state of service for many years have always been a concern of researchers. However, the research on this subject has been limited due to the difficulty in implementing destructive tests on real bridges. In this paper, a destructive test of a 43-year-old reinforced concrete simply supported T-beam bridge was carried out in Ningxiang County, Hunan Province. The stress behavior of the bridge under test and the structural response under extreme conditions were investigated. Firstly, the material strength, structural damage and degradation of the bridge are investigated in detail. Two 5000 kN jacks are used to load the bridge until the structure is damaged. Based on this, the finite element analysis is carried out and compared with the experimental results. The experimental results show that due to the influence of the integral connection, the boundary conditions and the initial damage, the mechanical behavior of the experimental bridge shows the local nonlinearity not found in the structural model and the finite element analysis. However, the finite element analysis And the test results show a certain degree of agreement. The failure mode of the test bridge is the typical flexural structural failure of yielding and then crushing of concrete, except for the crushing of the top of the bridge and other parts of the bridge also showed signs of damage, indicating the destruction of the actual bridge The form can be controlled by several factors.