Centrifuge Modeling of Highway Embankment Improved by Hybrid Type Reinforcement

The 2016 Kumamoto Earthquakes destroyed a few highway embankments of the Kyushu Expressway in the Kumamoto province, located at the saturated, loose sandy foundation. To reduce the potential risk of earthquake-induced damage, such as these embankment failures, an innovative low-cost hybrid type reinforcement was developed, consisting of vertical and inclined piles. This study presents a series of centrifuge tests modeling the performance of highway embankments subjected to embankment failure. The sinusoidal wave with a peak shaking amplitude of 0.2 g was adopted. Several aspects regarding the behaviors of excess generation of pore water pressure, pile bending moment and embankment settlement under four configurations were revealed and discussed. The centrifuge test results illustrate the hybrid type reinforcement with the angle (55°) between the vertical and inclined pile which has the greater performance during the dynamic loading.