ABSTRACT
The paper reviews geological and geotechnical characteristics of Ariake clay of Japan. The Ariake clay of Kyushu consists of lowland Quaternary soft deposits around the big inland Ariake Sea. Mountains and the inland Ariake Sea geographically surround the Saga plain at Kyushu Island of Japan. The deposit shows great variation in material thickness, sensitivity and softness. The top clayey soil is generally 10 to 20m thick with a maximum of 30m thickness. Clay minerals in Ariake clay are montmorillonite/smectite, illite, hydrohalloysite and metahalloysite with lots of diatom remains. Typical problems associated with poor bearing capacity, shear failure, slope instability and excessive settlements of the ground and foundation structures are discussed. Probable natural disasters are soil shear failure, land subsidence, and flooding owing to its inherent weak ground characteristics as lowland deposits. Based upon previous studies, a summarized correlation of engineering properties of Ariake clay is presented. These characteristics when linked with engineering insights will be very helpful for future infrastructure development.
