RESPONSE OF SATURATED/UNSATURATED GRAVELLY SAND TO TIDAL FLUCTUATIONS

摘要

This study was motivated by a recent case history of the formation and collapse of cavities in unsaturated granular backfill behind a seawall. It aims at developing a framework to assess the role of suction in the performance of granular soils subjected to complex hydro-environmental loading such as tides and waves. For this purpose, an elastoplastic constitutive model for unsaturated soil was incorporated into a coupled stress-flow analysis procedure using the finite element method. Predictions were made of suction and moisture changes in a beach of gravelly sand due to tidal fluctuations over a period of one month. It is shown that the predicted performance compares favorably with the performance of field measurements obtained by the Himeji office, Ministry of Land, Infrastructure and Transport, Japan.