ABSTRACT
To compute the expected lifetime seismic damage cost in the minimum life-cycle cost model, the limit state probabilities are usually evaluated by some practical methods in order to lessen the computational burden during the optimization process, such as, the procedure proposed by Wen and his group based on the uniform hazard ground motion and the equivalent SDOF system (Wen & Kang 2001a,b, Liu et al. 2003), the SAC/FEMA method based on the assumptions of lognormal distributions for randomness in seismic demands and capacity (Liu et al. 2004, Foley et al. 2007, Alimoradi et al. 2007), and the simplified fragility analysis method formerly proposed by the authors based on the three levels of seismic design
criteria in Chinese code (Wang & Lu 2001, Wang et al. 2003, Lu et al. 2002, 2006). However, all the above mentioned methods are approximate in nature. To account for the uncertainties more accurately and efficiently, the finite element reliability method is used in this paper to calculate the probability of exceedance of structural responses given the occurrence of seismic events.
