某钢—混凝土组合梁荷载试验评估分析

Load test evaluation and analysis of a steel-concrete composite beam

钢—混组合梁在当前桥梁跨越结构选型中得到了较为广泛的应用,目前对于其健康服役状态的评价显得尤为重要。基于某钢—混组合梁荷载试验项目,首先通过设计荷载确定了荷载弯矩效应,并根据荷载等效原则确定了加载车辆及布置位置。然后对于静载、动载结果进行了分析,结果显示桥梁应变、挠度实测值均小于模型计算值,且相对残余<20%,说明结构处于正常弹性工作状态;桥面板下缘与钢主梁顶板应变大小和变化趋势一致,说明二者协同工作;模态分析结果显示结构频率实测值高于模型计算值,即结构实际刚度高于理论刚度。文章系统研究了钢—混组合梁的荷载试验,对于其他类似桥梁的检测评定提供一定的理论和工程经验。

The steel-concrete composite beams have been widely used in the selection of bridge spanning structures,and it is particularly important to evaluate their health service status.Based on the load test project of a steel-concrete composite beam,the load bending moment effect is determined by the design load,and the loading vehicle and layout location are determined according to the principle of load equivalence.Then the static load and dynamic load results are analyzed.The results show that the measured values of bridge strain and deflection are less than the theoretical values,and the relative residual is less than 20%.The structure is in normal elastic working state;The strain magnitude and change trend of the lower edge of the bridge deck and the top plate of the steel girder are consistent,indicating that they work together;The modal analysis results show that the measured value of the structural frequency is higher than the theoretical value,and the actual stiffness of the structure is higher than the theoretical stiffness.This paper systematically studies the load test of steel-concrete composite beams,which provides some theoretical and engineering experience for the inspection and evaluation of other similar bridges.