基于外观和试验检测的石拱桥技术状况及承载能力评定

Technical condition and bearing capacity evaluation of stone arch bridges based on appearance and experimental testing

为研究在役公路石砌圬工拱桥运营安全状况及结构承载能力,对一座修建30多年的石拱桥进行尺寸测量、病害外观检测,采用分层综合评定方法对石拱桥技术状况评定,根据现场取材进行强度试验检测推定材料强度参数并建立Midas Civil有限元模型,对石拱桥在汽车-20级、挂车-100(JTJ 021-89)及公路-Ⅰ级(JTG D60-2015)两种新旧车辆荷载标准下的承载能力进行分析。研究表明:1)本工程石拱桥按照分层综合评定方法进行技术状况评定结果为2类,结构有轻微缺损,对使用功能无影响;2)根据有限元分析结果,主拱圈拱顶、1/4跨、拱脚截面的承载能力均满足荷载等级为汽车-20级、挂车-100及公路-I级的要求。本文研究方法及成果可为类似工程提供一定的借鉴。

In order to study the operational safety status and structural bearing capacity of a stone masonry arch bridge in service on highways, a stone arch bridge that has been built for more than 30 years was measured in size and inspected for defects and appearance.The technical condition of the stone arch bridge was evaluated using a layered comprehensive evaluation method.The strength parameters of the material were estimated by strength testing based on on-site materials, and a Midas Civil finite element model was established to analyze the bearing capacity of the stone arch bridge under two new and old vehicle load standards: Auto-20,Trailer-100(JTJ 021-89),and Highway-I(JTG D60-2015).The results showed that: 1)The technical condition of the stone arch bridge in this project was evaluated as Class 2 according to the layered comprehensive evaluation method, with slight structural defects and no impact on its functional use;2)According to the finite element analysis results, the bearing capacity of the arch crown, 1/4 span, and arch foot section of the main arch ring all meet the requirements of load levels of Car-20,Trailer-100,and Highway-I.The research methods and results of this article can provide some reference for similar projects.