Abstract
In the construction site of tidal flat made of dredged clayey soil, submerged breakwater and seawall are developed at first and coverd sand layer. If the foundation is firmly, submerged breakwater and seawall are able to construct with direct set of gravel. Foundation is soft condition on the contrary, ground improvements are need. In this study, applicability of geotextile bag filled with dredged clayey soil is examined to construct submerged breakwater on soft ground instead of gravel. Centrifuge model tests and numerical analyses were carried out to construct 3m of height of submerged breakwater using geotextile bag on normally consolidated ground.