Damage Ratio of Water Pipes during the 2007 Niigata-Ken Chuetsu-Oki, Japan, Earthquake

This study investigates the relationship between damage ratios of water pipes and seismic motion intensity after the 2007 Niigata-ken Chuetsu-oki, Japan, earthquake. The damage ratios of water distribution pipelines within a 2 km radius from the seismic observation stations are calculated in Kashiwazaki City, Niigata Prefecture. The damage ratios are compared with the fragility curves that were empirically obtained after the 1995 Kobe earthquake. On the other hand, the damage ratios for the greater area are obtained with respect to the estimated seismic motion intensities. Based on the results, regression analyses are performed to reveal the characteristics of damage incidents to water pipes during the event.