Development of time-dependent fragility functions for deteriorating reinforced concrete bridge piers¹

Time-Dependent Seismic Fragilities of Older and Newly Designed Multi-Frame Reinforced Concrete Box-Girder Bridges in California

“…For instance, a very different time-dependent seismic fragility can be expected for two bridge columns that are built at the same time and designed by a similar specification but are located in different environments; accordingly, separate computations of fragility functions are required for each of them. Consequently, Rao et al (2017) proposed a framework in which the seismic fragility of structural components is modeled as a joint function of the ground motion intensity measure, IM, and the deterioration of RC bridge columns due to the chloride-induced corrosion degree, X. In their study, the change in both damage state capacities and seismic demands due to deterioration was captured and validated by experimental studies on columns subjected to accelerated corrosion.…”

“…In their study, the change in both damage state capacities and seismic demands due to deterioration was captured and validated by experimental studies on columns subjected to accelerated corrosion. In addition, a simple parameter exponential decay function was proposed by Rao et al (2017) to incorporate the median damage states' fragilities, with an increase in the deterioration measure. The following changes were made as a function of the degree of corrosion: (1) the area of the reinforcing steel is reduced, (2) the strength of the cover concrete elements is reduced, and (3) the bond strength is modified.…”

“…The following changes were made as a function of the degree of corrosion: (1) the area of the reinforcing steel is reduced, (2) the strength of the cover concrete elements is reduced, and (3) the bond strength is modified. A full description of the corrosion and structural deterioration model used in the study can be found in Rao et al (2017). The time-dependent median and dispersion coefficients adopted from the study carried out by Rao et al (2017) are listed in Table 8.…”

“…A full description of the corrosion and structural deterioration model used in the study can be found in Rao et al (2017). The time-dependent median and dispersion coefficients adopted from the study carried out by Rao et al (2017) are listed in Table 8.…”

“…In recent years, the researchers have begun addressing the effects of deterioration on the seismic fragility of structures. Rao et al (2017) developed time-dependent fragility functions for deteriorating RC bridge piers with different levels of reinforcement corrosion in CA. They investigated the effect of deterioration on the structural demand and capacities of both older and newly designed RC bridge columns.…”