First-passage probability of the deflection of a cable-stayed bridge under long-term site-specific traffic loading

Abstract

Long-span bridges suffer from higher traffic loads and the simultaneous presence of multiple vehicles, which in conjunction with the steady traffic growth may pose a threat to the bridge safety. This study presents a methodology for firstpassage probability evaluation of long-span bridges subject to stochastic heavy traffic loading. Initially, the stochastic heavy traffic loading was simulated based on long-term weigh-in-motion measurements of a highway bridge in China. A computational framework was presented integrating Rice's level-crossing theory and the first-passage criterion. The effectiveness of the computational framework was demonstrated through a case study of a cable-stayed bridge. Numerical results show that the upper tail fitting of the up-crossing rate is an appropriate description of probability characteristics of the extreme traffic load effects of long-span bridges. The average daily truck traffic growth increases the probability of exceedance due to an intensive heavy traffic flow and results in a higher first-passage probability, but this increased trend is weakening as the continuous increase of the traffic volume. Since the sustained growth of gross vehicle weight has a constant impact on the probability of failure, setting a reasonable threshold overload ratio is an effective scheme as a traffic management to ensure the bridge serviceability.

Fatigue Stress Spectra and Reliability Evaluation of Short- to Medium-Span Bridges under Stochastic and Dynamic Traffic Loads

“…The traffic growth has occurred not only in traffic volume, but also in the number of extremely overloaded trucks (Mei et al 2004;Han et al 2014). This phenomenon negatively influences existing bridges, via large maximum traffic load effects (Obeirn and Enright 2013; Lu et al 2017), exponential increases in fatigue damage (Theil 2016), and road roughness deterioration (Pais et al 2013). Research progress has been made on the fatigue life and serviceability evaluation of existing steel and concrete bridges Lu et al 2017).…”

“…This phenomenon negatively influences existing bridges, via large maximum traffic load effects (Obeirn and Enright 2013; Lu et al 2017), exponential increases in fatigue damage (Theil 2016), and road roughness deterioration (Pais et al 2013). Research progress has been made on the fatigue life and serviceability evaluation of existing steel and concrete bridges Lu et al 2017). For short-to medium-span bridges, deteriorating road roughness conditions (RRCs) can lead to more stress cycles and high stress amplitudes due to dynamic impacts (Zhang and Cai 2012).…”

Probabilistic evaluation of maximum dynamic traffic load effects on cable-supported bridges under actual heavy traffic loads

“…Therefore, statistical analysis of the vehicle spacing was conducted using the driving speed and recording time data. All of the vehicle spacings were divided into the dense traffic and the free traffic according to a threshold value of time interval of 2 s. 31 The two types of PDFs of the vehicle spacing are shown in Figure 7. It is observed that the vehicle spacing in free traffic follows lognormal distribution, and that in denser traffic follows Gamma distribution.…”

Evaluating Probabilistic Traffic Load Effects on Large Bridges Using Long-Term Traffic Monitoring Data

“…In addition to traffic management, it can also provide a great amount of real traffic data for truck overloading identification and control. In practice, the WIM data has a wide range of applications in bridge engineering, such as live-load calibration in design specifications, fatigue reliability assessment, as well as lifetime maximum traffic load effects evaluation [22,23,24,25,26]. One of these achievements is the application of static load effects in the extrapolation of extreme value by conventional methods, such as general extreme value theory and level-crossing theory [27].…”