This paper describes the consolidation characteristics of aged clays in relation to geological history. As the results, it is shown that the consolidation yield stress of aged clays is influenced by the sedimentation curve of deposits, and the reference compression curve is closely related to index properties of aged clays. Also, pc-effect defined from the reference compression curve depends on the sedimentary age and the overburden pressure.
Along the shore Iine of Osaka Bay, Japan, many man-made islands have been constructed. The settlement of these islands is major concern for geotechnical engineers. It is difficult to accurately predict the consolidation settlement behavior of these islands, because there are such many clay deposits as a soft marine clay layer of Recent Deposit and underlying medium to stiff clay layers of Pleistocene Deposits. Especially, deeply deposited Pleistocene clays have been consolidated for such a long time as more than 10,000 years, which are called aged clays The authors have tried to elucidate consolidation behavior of the aged clays (Matsui and Sakagami (1992) This paper describes the consolidation characteristics of aged clays in relation to geological history. First, the effect of the geological history on the consolidatlOn behavior of aged clays is discussed The geological history for each clay layer is estimated, being based on the sedimentation curve of deposit that will be described later. Second, fundamental characteristics of compression curve of aged clays are discussed, followed by newly defining a reference compression curve, being based on laboratory consolidation test data of aged clays.
A comparison of the regional geological history and consolidation test data of deposits in Osaka Bay area is carried out The investigation sites are divided into such three areas as shown in Fig 1.
