Value based seismic design of structures using performance assessment by the endurance time method

Abstract

A framework for optimal seismic design of structures, considering maximum value as the design objective, is introduced. In this framework, the value parameter incorporates a comprehensive set of performance indicators. Decision indicators are mapped into equivalent economic values and are directly involved in the design process. This approach leads to optimal assignment of the available resources to meet infrastructure requirements. The construction cost and the risk of seismic consequences are considered as the value components. FEMA-P58 methodology is utilized in estimation of the seismic consequences including the repair cost, repair time, injuries and casualties. Endurance Time method is employed as an efficient procedure for estimating the engineering demand parameters at different seismic hazard levels. The applicability of the Endurance Time method is verified and compared to the results of Incremental Dynamic Analysis. The proposed design procedure is employed in design optimization of two multi-story buildings. Design outcomes are compared to the outcome of the conventional code-based design procedure minimizing the structural construction cost, in terms of seismic response and consequences. The value-based design approach considerably increases the total economic value of the studied structures. The code-based design in the studied cases is found substantially sub-optimal considering the maximum achievable value.