基于多点平滑的影响线提取方法研究及桥梁状态评估

Research on the Influence Line Extraction Method Based on Multi-point Smoothing and Bridge Condition Assessment

基于实测影响线的桥梁状态评估具有不中断交通、测试方便等优点,是未来中小跨径桥梁承载能力评估的重要方式,目前在实际桥梁上应用的案例较少。为此,先开展基于多点平滑的影响线提取方法研究;后结合挠度数据和应变数据,提取桥梁挠度影响线和应变影响线;在此基础上,再开展基于峰值的桥梁状态评估和基于设计活载响应对比的桥梁状态评估。结果表明:1)建立的影响线方法可用于实际桥梁的挠度和应变提取影响线,尤其是测试结果出现很多芒刺时,采用五点三次平滑法既能保证数据准确,又能平滑数据;2)评估结果显示,挠度校验系数在0.29~0.46之间,应变校验系数在0.10~0.37之间,表明测试桥跨的刚度和强度在现有状态下满足通行设计活载的要求。

The bridge condition assessment based on the measured impact lines has the advantages of no traffic interruption and convenient testing,which is an important way to assess the bearing capacity of small and medium span bridges in the future.There are few cases of application on actual bridges.Therefore,this study is first carried out on the influence line extraction method based on multi-point smoothing;Then,in combination with the deflection data and strain data,the deflection influence line and strain influence line of the bridge are extracted.On this basis,the bridge state assessment based on the comparison of peak value and design live load response is carried out.The results show that the influence line extraction method established in this paper can be used to extract influence lines for deflection and strain of bridges,especially when the test results show many awnings,and the five-point three-time smoothing method can be used to smooth the data while ensuring the accuracy of the data.The evaluation results show that the deflection calibration coefficients range from 0.29 to 0.46 and the strain calibration coefficients range from 0.10 to 0.37,indicating that the stiffness and strength of the tested bridge spans reach the requirements of the design live load for passing in the existing condition.