Basis for Risk Management on Bridges on Seismic Zones

摘要

The acceptable failure probability for bridges is calculated throughout the expected cost of failure consequences. The bridge expected life-cycle cost is formulated in terms of the bridge seismic hazard and the potential consequences of failure. These consequences include from the physical loss of the bridge to the human casualties and economical cost of the loss of service, which are estimated in monetary terms. Monte Carlo simulation techniques are used to explicitly account for the uncertainties. Initial and failure cost curves are determined for all possible soil accelerations and expected costs conditional to these accelerations are obtained. The unconditional life-cycle cost is calculated by convolution considering the seismic hazard curve of the site. The procedure is illustrated throughout a reinforced concrete bridge on the soft soil of Mexico City. The results may be extended to get risk management policies to improve the current Mexican codes and to enhance the practices on bridge design and maintenance on seismic zones.