中小跨径桥梁病害调查与损伤状态的快速识别方法研究

Research on Damage Investigation and Rapid Identification Method of Small and Medium Span Bridges

为了研究当下中小跨径桥梁广泛存在的开裂损伤问题,通过对赣北地区九江市范围内的柴桑区、修水县和庐山市的28座空心板桥、混凝土小箱梁桥与刚构桥进行病害检查,发现在重载交通作用下,桥面系、支座和下部构件等部位出现竖向开裂与网裂占比较高。依托曲率模态理论,提出一种一阶曲率模态损伤因子比(DFR)的桥梁损伤快速识别方法。通过对一座典型中小跨径简支梁桥进行5%~80%的单损伤工况和20%~90%的多损伤工况的预设损伤识别,结果表明桥梁损伤部位的模态曲线具有明显突变,能够满足桥梁初始损伤的定位需求。最后,对桥梁表观耐久性与内部性能监测进行了预测和分析。

In order to study the widespread cracking damage problem of medium and small span bridges at present,through the disease inspection of 28 hollow slab bridges,concrete small box girder bridges and rigid frame bridges in Chaisang District,Xiushui County and Lushan City in Jiujiang City,northern Jiangxi Province,it is found that under the action of heavy load traffic,vertical cracking and mesh cracking were relatively high in the bridge deck system,bearings and lower components.Based on the curvature mode theory,a rapid damage identification method based on first-order curvature mode Damage Factor Ratio(DFR)was proposed.A typical small and medium span simply-supported beam bridge was identified with 5%~80%single damage conditions and 20%~90%multiple damage conditions.The results show that the modal curve of the damaged part of the bridge had obvious mutation,which can meet the needs of the initial damage location of the bridge.Additionally,the bridge apparent durability and internal performance monitoring were predicted and analyzed.