Proposed time-dependent approach to seismic loss evaluation through the life cycle of a structure

In this paper, an efficient time-dependent approach to seismic loss evaluation is proposed to calculate the probability distribution function of the life cycle cost of a structure. In the current literature, the evaluation of seismic loss has almost exclusively focused on estimating the mean value of the life cycle cost which does not include the information about the full extent of seismic loss variability. The proposed method aims to employ the FEMA-P-58 approach in evaluating the probabilistic distribution of total seismic repair cost in the life cycle of a structure. This method also considers the effect of time-dependent phenomena on loss evaluation while it keeps the required computational effort at an affordable level. A Monte Carlo sampling technique is applied to consider all sources of uncertainties. In this approach, the appropriate response distribution of the structure is extracted from the incremental dynamic analysis results, and there is no need to repeat complex dynamic analysis calculations in each realization. To better demonstrate the proposed method, the life cycle cost of a 5-story steel special moment frame is investigated with various assumptions on its time-dependent specifications such as the monetary discounting effects, the influence of different discount rates and building depreciation over time.