基于健康监测的钢-混组合梁桥疲劳安全评估

Fatigue safety assessment for steel-concrete composite bridge based on health monitoring

为研究钢-混组合梁桥运营期间疲劳安全性能,基于山东枣木高速公路某钢箱组合梁桥健康监测系统,开展钢-混组合梁桥疲劳评估研究。根据动态称重系统(WIM)和动应变监测系统获取交通荷载信息和钢主梁受拉翼缘应力历程曲线,利用有限元软件平台进行车流模拟加载确定栓钉细节疲劳应力谱,采用疲劳累积损伤理论和断裂力学理论分别对钢-混组合梁桥疲劳敏感细节进行疲劳安全评估。研究结果表明,采用健康监测数据能够快速、高效地对钢-混组合梁桥进行疲劳安全评估,栓钉细节疲劳损伤显著大于钢主梁受拉翼缘;当前交通荷载作用下结构疲劳性能够满足设计需求,在运维期间应重点关注交通荷载变化和结构检测结果,定期开展钢-混组合梁桥疲劳安全评估工作。

In order to study the fatigue safety performance of the steel-concrete composite girder bridge during operation, the fatigue evaluation of steel-concrete composite girder bridge was carried out based on the health monitoring system of a steel box composite girder bridge on Zaomu Expressway in Shandong Province. According to the Weigh-In-Motion(WIM) system and dynamic strain monitoring system, the traffic load information and stress history curve of tensile flange in steel girder were acquired, and the fatigue stress spectrum of the stud de-tail was obtained by traffic flow simulation loading on the finite element software platform. Fatigue cumulative damage theory and fracture mechanics theory were adopted to perform the fatigue safety assessment of fatiguesensitive details for steel-concrete composite details. Research results show that the fatigue safety assessment of the steel-concrete composite girder bridge can be carried out quickly and efficiently based on the health moni-toring data. The fatigue damage of the stud detail is significantly greater than that of the tensile flange of steel girder. The fatigue performance of the structure under the current traffic load can meet the design requirements.During the service and maintenance period, attention should be paid to the change of traffic load and the struc-ture inspection results, fatigue safety assessment of the steel-concrete composite girder bridge should be carried out regularly.