宽幅变截面钢混组合连续梁桥荷载试验研究--以福州新建洪塘大桥东引桥辅航道桥为例

Load test research on a steel-concrete composite continuous beam bridge with the wide and variable cross-section--Taking the approach bridge of the new Hongtang bridge in Fuzhou as an example

福州新建洪塘大桥东引桥辅航道桥,为主跨72 m、宽度31.75 m的变截面钢混组合连续梁桥。为研究桥的结构性能,以该桥为例,通过Midas Civil有限元软件,模拟分析宽幅钢混组合连续梁桥在试验荷载作用下的静力和动力响应;再通过现场荷载试验,测试桥梁结构的静力和动力特性,并将结果与有限元模拟结果进行对比分析,评定桥梁结构性能。结果表明:挠度校验系数为0.34~0.99,应变校验系数为0.07~0.99,满足相关规范要求;前3阶自振频率均大于理论值,动力放大系数为0.054,动力特性和响应正常;结构整体受力性能良好,满足设计要求。

The approach bridge of the new Hongtang bridge in Fuzhou is an I-shaped steel-concrete composite continuous beam bridge with a main span of 72 m and a width of 31.75 m.In the interests of investigating the integral structural performances of the adopted bridge,taking the bridge as an example,the bridge finite element model is built and the dynamic and static responses of this bridge are analyzed under dynamic and static loads by the Midas Civil software.Afterwards,the load tests are performed on the spot,and the static and dynamic response time histories of this bridge are recorded at the same time.Finally,by comparing the data recorded on site with the outcomes of the finite element model,the accuracy of load tests is verified as well as the structural performances are evaluated.The results show that the deflection calibration coefficient is 0.34-0.99,and the strain calibration coefficient is 0.07-0.99,meeting the requirements of the relevant specifications;the first three natural frequencies are all greater than the theoretical values,and the dynamic amplification factor is 0.054,implying the dynamic characteristics and responses are normal;the integral structural performances remain good,which meets the design requirements.