FIELD EXPERIMENT OF THE EFFECT OF GRAVITY DRAINAGE SYSTEM ON BEACH STABALIZATION

摘要

To have a coastal protection work of high quality, we are developing a new beach protection system, that is a beach drainage system, in which the groundwater is naturally drained to the offshore through a permeable layer setting up under the beach. To examine the drainage function of the permeable layer and its effect on the beach stabilization, a field experiments have been conducted during storms. As a result, it is confirmed that the permeable layer drain the groundwater garvitationally into the surf zone and has a function of decreasing a speed of erosion in a storm, and the eroded foreshore is recovered quickly in a calm.