Bridge maintenance management based on routine inspection data: a quantitative approach

The United States National Bridge Inventory (NBI) records element-level condition ratings on a scale of 0 to 9, representing failed to excellent conditions. Current bridge management systems apply Markov decision processes to find optimal repair schemes given the condition ratings. The deterioration models used in these approaches fail to consider the effect of structural age. In this study, a condition-based bridge maintenance framework is proposed where the state of a bridge component is defined using a three-dimensional random variable that depicts the working age, condition rating, and initial age. The proportional hazard model with a Weibull baseline hazard function translates the three-dimensional random variable into a single hazard indicator for decision-making. To demonstrate the proposed method, concrete bridge decks were taken as the element of interest. Two optimal hazard criteria help select the repair scheme (essential repair, general repair, or no action) that leads to minimum annual expected life-cycle costs.

Analysis of the dynamic response of long span bridges with GNSS under typhoon loading

Nowadays, real-time bridge deformation monitoring has attracted more attention due to the development of bridge management system and land transportation safety. Huge civil engineering structures, such as long-span bridge, is susceptible to dynamic deflection caused by various loadings. Hence, precise dynamic response measurement becomes necessary to make structure more reliable and integrated. Currently, Global Navigation Satellite System (GNSS) positioning technology has been commonly used in this field to detect the dynamic displacement of long-span bridges. According to this, real-time data were collected from the Forth Road Bridge to observe the dynamic response of lang span bridges under extreme wind load conditions and this report has also verified the data processing technique of the real-time bridge deformation monitoring system. Compared with other monitoring methods, the method used in this report which combines GNSS and anemometer together has features of high frequency with low lag. Moreover, it also shows the superiority of post-processing and synchronization, background noises could be reduced by embedded software. Finally, according to the cross-correlation analysis, it was found that wind speed and bridge displacement in y-axis have the highest correlation. Also, the reliability of combining method to monitor the dynamic response of long-span bridge and noise reducing method proposed in this report has also been verified.