EXPERIMENTAL STUDY ON EFFECTIVENESS OF GABIONS AGAINST TSUNAMI SCOUR AT LANDWARD TOE OF COASTAL DIKE

Abstract

 The effectiveness of gabions against tsunami-induced scour at the landward toe of a coastal dike was investigated from hydraulic experiments. Experimental results showed that the installation of gabions moved a scour hole landward and reduced its maximum depth. This effect was reconfirmed from the hydraulic experiments in addition to existing numerical analyses not considering the leakage of sand and the displacement of gabions. Furthermore, it was found that a scour hole grew rapidly due to sand leakage after the gabions were displaced largely. This suggested that connected gabions could be more effective to reduce the displacement of the gabions and the gaps between the gabions.