Spatial time-dependent reliability analysis of corroding pretensioned prestressed concrete bridge girders

Reliability of Prestressed Concrete Bridge Girders Using Field Information and the Combined Approach

“…Other variables in Table 2 account for the uncertainty related to prestressing steel ultimate strength, fpu, the prestressing steel area (for each tendon), Aps, and the prestress loss, PLoss, (it is considered that 30% of the prestressing force is lost for a return period over Tr = 50 yr). Since statistics for the prestress are not readily available for the Mexican practice, but the nominal values of Mexican manufactures are very similar to those reported in the literature, they are adopted from (or based on) other works for fpu [6], Aps [1,9] and PLoss [4,5]. The statistics for flexural moments due to live load, L, are based on a previous study [21]; they are dependent on span length, not only for single vehicle passage, but also for multiple presence (both are considered).…”

“…This is derived, in one hand, by considering a coefficient of variation equal to 0.065 for Lspan=30 m, for the case of single vehicular passage [21], which is the relevant scenario for dynamic amplification; on the other hand, to include the coefficient of variation for the dynamic effect, a value is adopted from other work and equal to 0.10 [5]; the previous coefficients of variation are used to derived the coefficient of variation of the total (static plus dynamic) live load effects, under the assumption that the square root of the sum of the squares can be used to compute the total coefficient of variation [25] (like if both effects were normally distributed), and this resulted in the value of 0.12 referred above. It is acknowledged that this is not the most rigorous possible treatment of the dynamic live load effect, and future work is recommended.…”

“…Recent studies on reliability of prestressed concrete beams and bridge girders include sensitivity analysis using updated databases on materials [1], comparison of different standards [2], spatial and time depend reliability under corrosion and/or cracking effects [3,4,5], beams exposed to fire [6] or considering creep models [7], and calibration tasks [8], among other issues.…”

The sensitivity of bridge safety to spatial correlation of load and resistance

“…Spatial variability research carried out to date has been mainly focused on predicting the performance of corroding structures and spatial variability of the common parameters such as material, dimension and environmental properties Karimi et al 2005;Stewart 2005;Darmawan and Stewart 2007;Marsh and Frangopol 2008;Kenshel and O'Connor 2009;Akiyama et al 2010;Zhai and Stewart 2010). A major shortcoming in the work to date is that the spatial variability and corresponding correlation associated with applied loads and load effects has not been allowed for.…”

Spatial time-dependent reliability analysis of reinforced concrete slab bridges subject to realistic traffic loading

“…Spatial variability research carried out to date has been mainly focused on predicting the lifetime condition of a corroding structure and spatial variability of material, dimensional and environmental properties Karimi et al 2005;Stewart 2005;Vu and Stewart 2005;Darmawan and Stewart 2007;Marsh and Frangopol 2008;Kenshel and O'Connor 2009;Akiyama et al 2010;Zhai and Stewart 2010). A major shortcoming in the work carried out to date in this regard is that only structural capacity and damage have been considered -the spatial variability and corresponding correlation associated with applied loads has not been allowed for.…”