Abstract
Due to a wide variety of unforeseen conditions and circumstances, it will never be possible or practical to design or build a bridge that has a zero percent probability of failure. Structural aging, environmental conditions, and reuse are examples of circumstances that could affect the reliability and the life of a bridge. There are needs of periodic inspections to detect deterioration resulting from normal operation and environmental attack or inspections following extreme events, such as strong-motion earthquakes or hurricanes. To quantify these system performance measures requires some means to monitor and evaluate the integrity of bridges while in service. Due to several bridge failures, considerable advances have been achieved in research on structural health monitoring and nondestructive damage detection in the recent years.