ABSTRACT
As the structures has been enlarged and the construction works have been carried out in the deeper sea areas, the loads due to constructions has become close or larger than the consolidation yield stress of the Pleistocene clay layer at the large depth. In this report, the settlement problem of aged Pleistocene clay layer was reviewed with related to the cases in coastal projects. A reason of the large compressibility of Pleistocene clay is the structure due to the aging effect, which can be evaluated by the concept of the standard compression curve. The use of lightweight soil is a hopeful measure for the settlement. The newly developed LWTS method and the cases in the airport project are introduced.
