Study on Reinforcement Method of Small Earth Dams Using Steel Sheet Piles: Verification of reinforcement effect against the liquefaction through the shaking test

It is an important and urgent challenge to establish disaster prevention technologies for small earth dams for agriculture, as a defensive measure against damage from a large-scale earthquake such as a Nankai Trough Earthquake. A construction method utilizing steel sheet piles with excellent toughness has a track record of installation as an anti-earthquake measure for coastal levees, and the authors are examining adapting this method for reinforcement of small earth dams. As part of this study, the modeled small earth dams were subjected to permeation, excitation, and overtopping experiments, and as a result, it was determined that the conventional counterweight fill method has limited effectiveness as a measure to counter liquefaction of foundation ground occurring in the event of a large-scale earthquake because it is focused on sliding failures. On the other hand, it was confirmed that providing sheet piles in the body of a small earth dam is effective for reduction of disaster damage in the surrounding villages, because the sheet piles maintain the height of small earth dams and thus it is possible to suppress they breaks due to an earthquake or overtopping water.