2020 Volume 76 Issue 2 Pages I_461-I_468
Gabion revetments have been installed in front of a beach scarp formed due to high waves as a measure against further scarp formation. Although gabion revetments are unable to completely protect the sand behind the structure unlike other inpermeable revetments, they induce natural recovery of the beach profile because of their permeability allowing cross-shore sand transport while protecting the eroded beach from wave forces. This study evaluate the performance of a gabion revetment formed by the round-shaped gabions so-called ’daruma-kago’ which have high frexibility in arranging a revetment and have higher long-term durability because of the efficiently packed rock fills. The round-gabion revetment shows sufficiently high stability against waves with an ordinary water level. The stability of the revetment in higher water level is found to be improved by changing the arrangement of the round gabions. Although porosity of the gabion and the gap between the round gabions allow sand to move through the gabion structure, the round gabions showed to slow down the development of a beach scarp. Also the round-gabion revetment was found to show more efficient beach-protection function if we enhance the sand protection function of the gabions by wrapping it with geotextile.
