Life-Cycle Cost Effective Optimal Seismic Design for Continuous PSC Bridges

Abstract

A systematic procedure is developed for the reliability-based seismic safety level for bridge life-cycle cost design criteria of continuous PC bridges. In the paper, a set of cost function models for life-cycle cost analysis of bridges is proposed. The total life cycle cost functions consist of initial cost and direct/indirect damage costs considering repair/replacement costs, human losses and property damage costs, road user costs, and indirect regional economic losses. The damage costs are successfully expressed in terms of Park-Ang median global damage indices and damage probabilities. To compute Park-Ang median global damage indices and damage probabilities, SMART-IDARC-BRIDGE, a modified version of the well-known IDARC-BRIDGE, incorporating the simplified Monte Carlo simulations and system reliability for multi-unit PC bridge is used. Earthquake ground motions used to simulate the realistic loading condition are obtained from non-stationary filtered Gaussian processes with both frequency and amplitude modulations based on the Yeh-Wen stochastic ground input motion model. The proposed approach is applied to model bridges of both moderate seismicity regions like Korea and high seismicity regions like Japan and various sensitivity analyses are performed to identify governing parameters. From the results of the numerical investigation, the proposed approach can be effectively utilized for optimal seismic safety level for bridge lifecycle cost design criteria.