Active fault investigation and slope stability evaluation for Aso Bridge in Japan

Abstract

The Aso Bridge in Japan is located near the Futagawa Fault, which is considered to be the epicentre fault of the Kumamoto earthquake. This paper presents the technical findings obtained through the investigation and design of the Aso Ohashi Bridge replacement project after the Kumamoto earthquake, including (a) extraction of active fault zones, (b) evaluation of fault activity found on the cut slope and (c) stability evaluation of the excavated surface behind the bridge piers considering the mechanical properties of the columnar joints.