Seismic vulnerability assessment of process towers using fragility curves

SUMMARY This study focuses on the seismic vulnerability assessment of process towers. A 96-m process tower, located at the Shazand Refinery, is considered for a case study sample. The vulnerability of this structure is expressed with the development of fragility curves, which provide the probability of exceeding a prescribed level of damage for a wide range of ground motion intensities. The methodology of developing fragility curves for process towers is shown. The developed fragility curves can be very useful for emergency management agencies and insurance companies wishing to estimate the overall loss after an earthquake. The vulnerability of nonstructural equipments of tower is also assessed in subsequent step. To model the process tower with its base details, a nonlinear finite element model is generated. It was found that the fragility curves should be developed for external pressure condition because it is more critical state of loading. The results show that the damage to the process tower occurs in the shell; and the other types of damages, i.e. yielding of anchor bolts, structural damage to foundation and overturning of tower, do not occur. Copyright © 2013 John Wiley & Sons, Ltd.