ABSTRACT
Following the disaster at Tokyo Electric Power Company’s Fukushima Daiichi Nuclear Power Station induced by the 2011 Tohoku Earthquake, Chubu Electric Power Company has been implementing countermeasures in Hamaoka Nuclear Power Station (NPS) against potential mega-earthquakes and mega-tsunamis. For this purpose, the L-shaped Tsunami protection wall 14–16 m high above the site, which is at an elevation of 6–8 m above sea level, was constructed along the coastline around the site. The total length of the protection wall was 1,600 m and it was fixed to the underground walls, which were embedded in rock mass to a depth of 10–30 m. Foundation rock consists of intercalated mudstone and sandstone. The performance and uplift resistance of the underground walls embedded in rock mass is investigated using centrifuge shaking table experiments with a scale of 1/30. Furthermore, finite element analyses for the full-scale of the protection wall were performed under a base acceleration up to 2,000 gals. The author describes these studies regarding the very unique actually built protection wall against megaearthquakes and mega-tsunamis and discusses its implication for important rock engineering structures for very similar dynamic conditions.
