Seismic rehabilitation of coastal dikes by sheet-pile enclosures

Past experience has shown that by far the most widespread source of earthquake-induced damage to coastal dikes and embankments has been liquefaction of the loose, saturated, sandy foundation soils that often prevail throughout the marine environment. In this paper, the potential of using sheet-pile walls for mitigating the adverse effects of foundation liquefaction on overlying coastal dikes-embankments is investigated through a series of heavily instrumented, dynamic centrifuge physical modeling tests. Mechanisms of earthquake-induced marine foundation liquefaction and associated hazards on a typical dike section are discussed based on the recorded dynamic response. The effectiveness of underground sheet-pile walls as retrofit is evaluated based on additional modeling tests.