Abstract
The third stage development area of Tokyo International Airport Extension Project is required to undergo soil stabilization by sand drain immediately after its reclamation by dredged clay of high water content. The centrifuge loading tests were conducted to check the satability of sand drains during driving and under embankment loading, and the necessity of using fabri-packed sand drains i. e. wrapping of geotextile envelopes, in such a clay was clarified. In this study the critical driving length of fabri-packed sand drains and the tensile strength of wrapping material against compression and bending of sand drains were investigated. As a result it was confirmed that the method can be used under practically estimated construction conditions without rapture of wrapping material securing the continuity of sand drain and consequently the method is adopted for the present area.
