BACK-ANALYSIS OF A CASE HISTORY USING FINITE ELEMENT METHOD: THE KANSAI INTERNATIONAL AIRPORT, JAPAN

摘要

The construction of large embankments on soft clays involves uncertainties regarding parameters determination, consolidation analysis, settlement prediction and creep effects in normally consolidated soils. The present paper investigates the settlement occurred during the construction of the second artificial island of Kansai International Airport in Osaka bay. The vertical displacement estimated before the construction was lower than the one measured due to unexpected excessive creep deformations. A thorough back-analysis was performed using PLAXIS 2D. The back-analyzed results for the seawall showed a very good match with the real settlement data at t=800 days. Finally, the long-term settlement has been investigated. The obtained value seems comparable with the one predicted by Akai and Tanaka (2005). Uncertainties might be due either to the additional loading given by the airport superstructure or to a refill of the constructed layers added in order to compensate for the excessive settlement that occurred.