SEISMIC DAMAGE MECHANISM OF SEWER BURIED PIPES BY SURFACE RUPTURES IN THE 2016 KUMAMOTO EARTHQUAKE

Abstract

 In the 2016 Kumamoto earthquake, sewer buried pipes were severely damaged. Although these damages are considered to be mainly caused by strong ground motion and liquefaction, earthquake surface ruptures widely emerged in the epicentral area are need to be examined as one of the causes. In this study, we revealed the characteristics of the affected pipes by surface ruptures from view of points of pipe types, diameter and classification of microtopography in Kumamoto City and Mashiki Town in the 2016 Kumamoto earthquake. And we analyzed the relationship between the damage modes and the crossing angle for the crossing points of the buried pipes. Moreover, we clarified the relationship between the displacements at the surface ruptures and damaged pipes.