摘要
为评定某主跨跨径320 m,全长600 m的新建预应力混凝土斜拉桥在成桥状态下的承载能力,对其进行了全面的静、动载荷试验。首先给出了采用有限元软件MIDAS进行斜拉桥空间建模分析的基本原则和主要构件(如主梁、主塔、辅助墩、斜拉索等)的单元类型和边界条件以及梁塔、梁索的连接设置方法。同时给出了荷载试验加载项目和工况优化原则及方法。为全面了解本桥试验情况,详细介绍了静、动载荷试验的测试断面布置和挠度、位移、索力等关键测试项目的测试方法。对主梁的应变、挠度、全桥挠曲线、塔顶纵向位移、斜拉索索力增量等静力测试结果与理论计算值进行了对比分析,对大桥振型、阻尼比等动载试验结果进行了分析,给出了试验荷载下混凝土箱梁关键控制截面应变分布规律和主梁竖向挠度及主塔纵向偏位的变形特征,以及应变、挠度等关键测试项目随荷载加载等级的变化情况,并对试验数据偏差情况进行了分析,在此基础上对大桥的承载能力及安全储备情况进行了合理评定。结果表明:该桥的实际承载能力满足设计要求,且安全储备较为合理;试验中既要保证测试工作的完备又需兼顾荷载试验效率,应尽可能对测试项目进行合理优化,当测试数据与理论值偏差较大时,应仔细分析数据偏差产生的原因,对偏差数据既不可盲目剔除也不可盲目采用,需要结合加载情况、测点布置等情况加以综合分析。
In order to evaluate the bearing capacity of a new prestressed concrete cable-stayed bridge with a main span of 320 m and a total length of 600 m in completion state,a comprehensive static and dynamic load test on it is carried out.First,the basic principles of space modeling and analysis of the cable-stayed bridge using finite element software MIDAS and the element types and boundary conditions of main components such as main beam,main pylon,auxiliary pier and cable,as well as the connection setting method of beam pylon and cable are given.At the same time,the principle and method of loading items in load test and condition optimization are given.In order to fully understand the test situation of the bridge,the layout of the test section and the test methods of the key test items such as deflection,displacement and cable force in the static and dynamic load test are introduced in detail.The static test result of the strain,deflection,deflection curve of the whole bridge,longitudinal displacement of the pylon top,cable force increment of the stay cable of the main girder are compared and analyzed with the theoretical calculation values.The dynamic load test result of the bridge such as vibration mode and damping ratio are analyzed.The strain distribution rule of the key control section of the concrete box girder,the vertical deflection of the main beam and the longitudinal deflection of the main pylon under the test load,and the changes of key test items such as strain and deflection with the load level are given,and the deviations of the test data are analyzed.On this basis,the bearing capacity and safety reserve condition of the bridge are evaluated reasonably.The result shows that(1) The actual bearing capacity of the bridge meets the design requirements,and the safety reserve is reasonable.(2) In the test,it is necessary to ensure the completeness of the test and the efficiency of the load test.The test items should be reasonably optimized as much as possible.When the test data deviates greatly from the theor
作者
熊海涛
刘志东
胡友强
宋春霞
XIONG Hai-tao;LIU Zhi-dong;HU You-qiang;SONG Chun-xia(China-Road Transportation Verification&Inspection Hi-Tech Co.,Ltd.,Beijing 100088,China;Beijing Gongke Bridge Technology Co.,Ltd.,Beijing 100088,China;Luda Branch of Guangdong Road and Bridge Construction and Development Co.,Ltd.,Meizhou Guangdong 514779,China;Research Institute of Highway,Ministry of Transport,Beijing 100088,China)
出处
《公路交通科技》
CAS
CSCD
北大核心
2022年第8期86-93,共8页
Journal of Highway and Transportation Research and Development
基金
中央级公益性科研院所基本科研业务费项目(2021-9072a,2021-9073a)。
关键词
桥梁工程
动力特性
静动载试验
斜拉桥
有限元计算
bridge engineering
dynamic characteristic
static and dynamic load test
cable-stayed bridge
finite element calculation
