Analytical fragility analysis of southern Illinois wall pier supported highway bridges

Abstract

SUMMARYAn analytical fragility analysis was conducted in order to characterize the seismic vulnerability of existing southern Illinois wall pier supported highway bridges to potential earthquakes. To perform this fragility analysis, a detailed inventory survey was first taken of the wall pier bridges identified in an earlier random sampling of southern Illinois priority emergency route bridges. From the survey three types of wall pier bridges were identified. Of those identified, hammerhead and regular wall pier supported bridges represented nearly 90% of the population. Incorporating structural variations determined from the random sample survey, nearly 100 three-dimensional nonlinear finite element models were constructed. Each model was subjected to a randomly assigned synthetic earthquake representative of those that could potentially occur within the region. From these analyses, a series of wall pier supported bridge fragility curves were produced. In addition, a liquefaction fragility analysis was conducted in order to characterize the seismic vulnerability of southern Illinois wall pier supported highway bridge sites to liquefaction in potential earthquakes. To perform this second fragility analysis, wall pier bridges within the southern Illinois random sample that may be susceptible to liquefaction were identified. A soil profile from each of these susceptible bridge sites was then subjected to randomly assigned bedrock motions, and an Arias intensity liquefaction analysis was carried out. From these analyses, a fragility curve for the potentially liquefiable wall pier supported bridge sites was produced. Overall results of this study indicate that southern Illinois wall pier supported bridges are moderately vulnerable to structural damage in a 2% probability of exceedance in 50 year earthquake, and in some cases they could also be highly vulnerable to on-site liquefaction events.

Seismic performance of highway bridges with fusing bearing components for quasi‐isolation

“…The results from this research are generally consistent with other studies on bridges in the NMSZ. When studying fragilities of wall pier bridges in Illinois, Bignell and LaFave found that overall, bridge systems in the region are expected to experience only moderate damage for the MCE‐level hazard, which is similar to the conclusions herein. Similarly, they noted that pier properties were important in the general bridge response, but in contrast to the study presented in this paper, they found that bearings (steel roller, low‐profile fixed, and elastomeric in some cases) had little influence on the bridge fragility.…”

Experimental study on seismic performance of steel fiber reinforced concrete wall piers

“…Although the single‐pier bridges have been addressed frequently in the literature, 10–18 the wall piers have been rarely evaluated 19‐25 and the safety index of these bridges is still questionable, in a design point of view, to promote comfort and economy in modern communities. Guidelines for the modern seismic design of the wall piers of reinforced concrete bridges based on employing special reinforcement details and requirements related to the minimum ductility of structural members ensure the occurrence of plastic behaviors and energy dissipation in severe earthquakes.…”

Seismic assessment of a multi-span steel railway bridge in Turkey based on nonlinear time history

“…Three methods are commonly employed to determine this: nonlinear time history, incremental dynamic, and capacity spectrum analyses, with time history analysis being the most commonly used tool (Banerjee and Shinozuka, 2007;Bignell et al, 2004;Shinozuka et al, 2000a;Mackie and Stojadinović, 2001;Kumar and Gardoni, 2014). Incremental dynamic analysis can also be used to determine the earthquake response of a structure and derive the fragility curve (Lu et al, 2004;Kurian et al, 2006;Liolios et al, 2011).…”