Keller executed non-dredged ground improvement method and its first major application of Keller offshore stone column technology.
Located at the northeastern coast of Singapore, Pulau Tekong, is the largest
remote island in Singapore. A land reclamation contract was awarded to
TOA Corporation and Jan De Nul Joint Venture.
In most parts of the project, dredging and filling was adopted to form the
perimeter bund prior to the construction of the sand key. However, this method
posed concerns of instability to the existing sand key. Keller proposed Offshore Vibro Replacement to improve the strength and deformation characteristics of the soft clay prior to sand filling. This also ensure that the foundation for sand key was stable during sand filling and to meet the settlement criteria of the rock revetment structure on the sand bund.
Approximately 43,000 linear meters of stone columns were installed using
Alpha-S and Keller Gravel Jet system. The Gravel Jet system allowed the
construction of columns to 25 m below sea level.