CONSTRUCTION OF THE FRAGILITY CURVES OF EXPRESSWAY EMBANKMENT BASED ON ACTUAL EARTHQUAKE DATA

ABSTRACT: Many major and minor damages were caused to various structures in the recent earthquakes in Japan. Among them, the embankments of expressways were severely damaged. Using both the actual damage data and estimated spatial distribution of seismic intensity, this study conducts the statistical analysis on the relationship between the damage ratio of expressway embankment and seismic intensity. Based on the results, the fragility curves of expressway embankment are constructed. The actual damage datasets used in this study were compiled for the 2003 Northern-Miyagi earthquake and the 2003 Tokachi-oki earthquake. Based on the obtained results, major damages affecting the traffic are found to occur in the area where the JMA instrumental seismic intensity is larger than 5.3. Slight damages are also found to occur when JMA seismic intensity exceeds 4.8. The fragility curves constructed in this study may be helpful to predict the damage distribution in the expressway at an early stage of an earthquake occurrence so as to make an efficient traffic control and a rapid disaster response