A set of one-dimensional consolidation apparatuses is developed to investigate consolidation behavior of clays under a wide range of applied pressures. The performance of developed apparatuses is checked through a series of consolidation tests. Then. consolidation characteristics of undisturbed Pleistocene clays which were taken from Osaka Bay area are investigated. Especially, the effect of applied pressures on the consolidation characteristics is discussed comparing those of undisturbed Pleistocene clays and reconstituted Holocene clays. It is found that consolidation behavior of both undisturbed Pleistocene clays and reconstituted Holocene clays is similar at applied pressures of over 500 kgf/cm2.
Many large-scale reclamation projects such as Port Island. Phoenix project, Kansai lntemational Airport. have been planned and carried out in Osaka Bay area. It is one of the most important problems in these projects to predict the consolidation settlement behavior of reclaimed lands dunng and after reclamation works. Therefore, it is essential to fully elucidate the consolidation characteristics of seabed deposits. In Osaka Bay area, there are Holocene deposits, underlain by thick Pleistocene clay layers which alternately deposited with stiff sand and gravel layers. These Pleistocene clays usually shows stress overshooting in the one-dimensional compression curve and are considered to be in a quasi-overconsolidated state because of aging effect. In this paper, the authors try to elucidate one-dimensional consolidation characteristics of undisturbed Pleistocene clays in a quasi-overconsolidated state under a wide range of applied pressures. Firstly, a set of onedimensional consolidation apparatuses is developed, in which pressures from the minimum of 0.2 kgf/cm2 to the maximum of over 1000 kgf/cm2 can be applied. Secondly. the performance of developed apparatuses is checked through a series of consolidation tests for reconstituted kaolin clays. Finally consolidation characteristics of undisturbed Pleistocene clays which were taken from Osaka Bay area are investigated under a wide range of applied pressures.
