Detailed in-situ and laboratory tests on the improved ground in Port Island

摘要

This paper describes results of the detailed in-situ and laboratory tests ont he decomposed granite (called Masado) obtained at the site in Port Island where the ground was improved by rod compaction and netiher ground deformation nor sand boil was observed during the 1995 Hyogoken-nambu earthquake. Physical and mechanical properties of intact samples taken by in-situ freezing sampling were obtained. They are compared with those obtained at an unimproved site where signififcant liquefaction occurred and many sand boil and ground deformation were observed. They are also compared with other materials in Japan. The characteristics of Masado were made clear through these investigation and comparison.