Forecasting earthquake losses in port systems.

摘要

Ports play a critical role in transportation infrastructure, but are vulnerable to seismic hazards. Downtime and reduced throughput from seismic damage in ports results in significant business interruption losses for port stakeholders. Current risk management practices only focus on the effect of seismic hazards on individual port structures. However, damage and downtime of these structures has a significant impact on the overall port system's ship handling operations and the regional, national, and even international economic impacts that result from extended earthquake-induced disruption of a major container port. Managing risks from system-wide disruptions resulting from earthquake damage has been studied as a central element of a Grand Challenge project sponsored by the National Science Foundation Network for Earthquake Engineering Simulation (NEES) program. The following thesis presents the concepts and methods developed for the seismic risk management of a port-wide system of berths. In particular the thesis discusses the framework used to calculated port losses: the use of spatially correlated ground motion intensity measures to estimate damage to pile-supported marginal wharves and container cranes of various configurations via fragility relationships developed by project team members, repair costs and downtimes subsequently determined via repair models for both types of structures, and the impact on cargo handling operations calculated via logistical models of the port system. Results are expressed in the form of loss exceedance curves than include both repair/replacement costs and business interruption losses. The thesis also discusses how the results from such an analysis might be used by port decision makers to make more informed decisions in design, retrofit, operational, and other seismic risk management options.