基于健康监测系统的大跨度多荷载悬索桥的疲劳与可靠度评估(英文)

在过去的几十年,世界各地建立了许多大跨度悬索桥。通常这些桥梁需承受多种动力荷载,尤其是一些处于多台风地区的公铁两用桥梁。为了保证这些大跨悬索钢桥在运营期内的安全和正常使用,有必要以一定的时间间隔进行桥梁的疲劳和可靠度评估。有鉴于此,许多大跨悬索桥都安装了健康监测系统,但是如何运用其进行准确的疲劳评估仍然是一个问题。本文通过结合计算机模拟技术和健康监测系统的测量数据,以香港青马大桥为例,分析了在多荷载作用下的大跨度悬索桥的疲劳和可靠度。同时,作为利用结构健康监测技术进行结构健康状态评估的这一重要研究方向的有益实践,该研究发展了一系列方法用于评估桥梁的疲劳,以及通过考虑存在于结构的物理模型和计算机模拟中的不确定性用以评估疲劳的可靠度。

Multiloading Long Span Suspension Bridges with Structural Health Monitoring Systems: Fatigue and Reliability

Many long span suspension bridges have been built throughout the world in recent years but they are often subject to multiple types of dynamic loads, especially those located in wind-prone regions and carrying both trains and road vehicles. To ensure the safety and functionality of these long span steel suspension bridges, fatigue and reliability assessment shall be performed from time to time during their service life. In this regard, structural health monitoring systems (SHMS) have been installed in a few long span suspension bridges, but it is not clear how to make use of SHMS for fatigue and reliability assessment. This study focuses on fatigue and reliability assessment of long span suspension bridges under multiple types of dynamic loads by integrating computer simulation with the measurement data from SHMS and by taking the Tsing Ma suspension bridge in Hong Kong as an example. This study leads to a powerful framework and an engineering approach for determining dynamic stress responses of long span suspension bridges under highway, railway and wind loadings. This study also narrows down the gap currently existing between structural health monitoring technologies and structural condition assessment practices by developing a few approaches capable of performing fatigue and reliability assessment with taking into account uncertainty and randomness inherent in both physical field and computer simulation.