基于健康监测的钢桁梁桥结构承载力可靠性评估

桥梁结构健康监测系统能有效监测桥梁结构上的各种作用及结构效应,可为准确评估桥梁结构状态提供信息。以一座钢桁梁桥健康监测数据为基础,研究基于健康监测的钢桥构件承载力可靠性评估方法,分析应变信号的特点,并根据一段时间内的健康监测数据对桥梁结构进行承载力可靠性分析,建立基于随机车辆荷载模型的桥梁承载力可靠性评估方法,探讨温度效应对结构承载力可靠指标的影响。结果表明:由移动车辆振动引起的钢桥构件应变很小,移动车辆荷载产生的静力响应对构件承载力可靠指标起控制作用;随机车辆荷载模型能较好地模拟实际列车通行情况,结合有限元方法,能快速对钢桥构件承载力进行可靠性评估;考虑温度效应后构件承载力可靠指标有所减小,且温差越大,变化越明显。

Reliability Assessment of Bridge Structural Bearing Capacity Based on Health Monitoring

The bridge structural health monitoring system can effectively monitor various functions and structural effects of the bridge structure and provide information for accurate assessment of the bridge structure state. Based on the health monitoring data of a steel truss bridge, this paper studies the reliability evaluation of the bearing capacity of steel bridge members, analyzes the characteristics of strain signals, evaluates the bridge structure according to the health monitoring data from a period of time, establishes the reliability evaluation method of bridge bearing capacity based on random vehicle load model, and discusses the influence of temperature effect on the reliability index. The results show that the strain caused by the vibration of the moving vehicle is very small, and the static response caused by the moving vehicle load controls the reliability index of the bearing capacity of the member;the random vehicle load model can better simulate the actual train traffic;the method can quickly evaluate the reliability of the bearing capacity of steel bridge members combined with the finite element analysis;the reliability index of the bearing capacity of the member is reduced with temperature effect, and the larger the temperature difference, the more obvious the change of reliability index.