SEISMIC DAMAGE ANALYSIS OF WATER SUPPLY FACILITIES CAUSED BY THE 2016 KUMAMOTO EARTHQUAKES: VERIFICATION OF PILES AND WELLS SEISMIC DAMAGE, AND THE ISSUES OF THE CURRENT SEISMIC DESIGN METHOD

Abstract

 The 2016 Kumamoto earthquakes had caused many damages on water supply facilities. Damages of water supply facilities associated with unexpected significant ground deformation, and foundation damages of the structures that meet the new earthquake resistant standard (standard for earthquake resistant design after 1981 in Japan) were reported at water supply well areas that surrounded by rivers and located in lowland with soft clay layer and saturated sand layer. As professional engineers and researchers who design and construct water treatment and sewage plants and pipelines, the authors conducted investigation and analyzation in order to find out the relevance between the damage of water supply facilities and the ground behavior including liquefaction during the earthquake. Based on the results of this study, we analyzed the seismic damage mechanism and factors, and discussed about the earthquake-resistant measures in future for the piles and well casings inside water distribution stations in water supply well areas, which are very important for the water supply system of Kumamoto City.