A predictive model for scour depth of coastal building failures due to tsunamis

The 2011 Great East Japan Earthquake and Tsunami was one of the strongest earthquakes which generated a major tsunami in modern history. The tsunami disaster had an estimated cost of 16.9 trillion yen (US 217.3 billion) and affected the Coastal buildings, services, infrastructure and industrial sectors. Approximately 61% of damaged cost was from the building sector. A practical predictive scour depth model at seaward face was developed to highlight the scour failure of Coastal buildings in Miyagi, Fukushima and Iwate prefectures affected by the 2011 Great East Japan Earthquake and Tsunami. The predictive model for representative scour depth was developed in terms of various hydraulic, geometrical and soil properties affecting Coastal buildings. An analysis was undertaken to investigate the effectiveness of the authors' predictive scour model against the existing models. The results of the authors' proposed model suggested that the tsunami velocity played a significant role on tsunami-induced scour, other scour models such as Tonkin et al.'s model (2003) is reliant on the accuracy of sub models and hydrodynamic forces while the Colorado State University model as modified by Nadal et al. (2010) is reliant on the geometric parameter of the structure.