Explicit Time‐Dependent Multi‐Hazard Cost Analysis Based on Parameterized Demand Models for the Optimum Design of Bridge Structures

Abstract

AbstractThis article presents an explicit cost analysis framework built upon the unified reliability method that introduces time‐dependent variables and multiple hazards as well as parameterized demand models into one cost‐based limit state function. In this approach, reliability‐based design of deteriorating structures subjected to natural hazards is performed using a cost limit state function, as opposed to traditional structural limit state in structural reliability methods. The flexibility of cost‐based limit state functions addresses the criticism of focusing on minimization of the total expected cost typically used in some available life‐cycle cost analysis methods. Furthermore, the framework has the capability to include deterioration models that are functions of time as well as recently developed parameterized structural capacity and demand models for various hazards. The application of the proposed framework is illustrated in a bridge design optimization problem where the column reinforcement bar diameter and concrete cover are considered as design parameters. Two locations in the New Madrid and San Francisco Bay Area seismic zones are assumed for the bridge and the optimum combination of concrete cover and bar diameter is obtained for each location.