Optimal seismic design for limited planning time horizon with detailed seismic hazard information

This study focuses on the optimal seismic design of buildings for the limited planning time horizon considering earthquakes generated from Poisson and non-Poisson processes. The analyses of the optimal design incorporate possible effects of the time elapsed since the last major earthquake, extended service period above the planning period and costs due to partial damage and collapse. An analysis algorithm is developed based on simulation technique, considering detailed seismic information; the evaluation of the linear/non-linear responses and different structural damage levels; and the assessment of the statistics of the damage cost. The algorithm is implemented and applied to simplified steel frame structures located in western Canada. Analysis results suggest that the optimal seismic design level is sensitive to the assumption of the cost of non-structural components. The analysis results also indicate that if the seismic hazard is dominated by earthquakes generated from a Poisson process, the impact of the extended service period after the planning period on the optimal design is not very significant. The impact of the elapsed time since the last major earthquake can be significant resulting in time-dependent optimal seismic design coefficients, if the seismic hazard is dominated by earthquakes generated from a non-Poisson process.