Probabilistic assessment of the seismic damage of a ramp bridge under main shock and aftershock: A case study

Construction of ramp bridges has increased with respect to the extension of cities and increasing their congestion andthe observations regarding the behavior of ramp bridges during and after earthquakes illustrate that these bridges havecomplicated behavior which has not been sufficiently studied in the previous investigations. Consequently, this paperis aiming at evaluating the vulnerability of an existing ramp RC bridge under the main shock and aftershock recordthrough a case study. This bridge is located in the north of Iran in Amol city and is one of the most important bridgesin this city whose fragility assessment can help to make the decision of retrofitting this bridge due to the high seismicityof this region. To do so, it is tried to examine the seismic fragility of this structure under the main shock and aftershockrecords by considering all the uncertainties regarding the materials, bridge specifications and seismic loads and withthe aid of Monte Carlo probabilistic assessment. The fragility of this structure is calculated and presented for fourdamage levels including: slight, moderate, extensive and complete. The results show that for the design earthquake inAmol city (recurrence period of ۴۷۵ years), the exceedance probability from the aforementioned four levels is ۰.۰۷,۰.۱۸, ۰.۳, ۰.۶۳ for main shock and ۰.۰۹, ۰.۱۹, ۰.۳۷, ۰.۷۵ for aftershock, respectively.

کلیدواژه ها:

Ramp Bridge ، Fragility Analysis ، Time History Analysis ، Main shock ، Aftershock