An experimental investigation was carried out to study the feasibility of using fly ash as a fill material for waterfront retaining structures. In the study, centrifuge model tests were performed on the cement stabilized fly ash ground with small amount of cement to investigate the failure and active earth pressure on the
retaining wall. In the test model grounds of 20 cm in height was brought up to the centrifugal acceleration of 70 g, which corresponded 14 m in prototype scale, and subject to the active failure. Earth pressure distributions acting on the retaining wall were measured during the loading and failure pattern of the ground was alsomonitored. The measured earth pressures were compared with the Column type equation and with a simple equation proposed in which shear and tension failures
could be taken account. It was found that the simple equation could well estimate the active earth pressure of the ground. It was also found that the active earth pressure was lower than conventional sand fill at the new application of the fly ash will add a new component to cost-effective developments in coastal areas.