Optimal earthquake-resistant design: A reliability-based, global cost approach

Abstract This paper presents a methodology for incorporating into the decision-making process of design the explicit consideration of possible future performance of the designed structure in the presence of uncertainty in both loading and structural parameters assumed in the design process. Design is viewed as an optimization problem, taking into account as a merit function terms related to building cost as well as possible future damage. Randomness of loads, load-effects, structural resistances and structural parameters affecting response are considered. In this framework a method suited both to linear as well as nonlinear structural behavior is presented. Approximate expressions of the probabilities of the above random variables as functions of the central moment of their distributions are introduced. Together with a firstorder expansion of the input-output response function characterizing the structural model, this procedure gives computational feasibility for actual design applications. An example is included to clarify the methodology proposed and to illustrate typical features of problem formulation and solution.