Geotechnical investigation in land reclamation

Reclamation of land from the sea has always played an important role in Southeast Asia. Reclaimed land is often created by the placement of sand fill over seabed soils that are dominated by soft to medium stiff marine clay. Geotechnical investigations prior to and after reclamation are important not only for planning and control of land reclamation but also for subsequent treatment of the underlying seabed soils as well as for geotechnical design in conjunction with the development of reclaimed land. The main concern of geotechnical investigation prior to land reclamation was the determination of soil profiles and obtaining key soil parameters such as stress history, compressibility and consolidation characteristics, strength and so on. After reclamation, geotechnical investigations were carried out mainly for the assessment of soil improvement. This chapter describes geotechnical investigation programmes carried out in a mega land reclamation project in Singapore. Determination of soil parameters from laboratory tests and in situ tests were introduced. Emphasis is put on the soil parameters interpreted from in situ tests including the piezocone test, the seismic cone test, the dilatometer test, the field vane test and the self-boring pressuremeter test.