Application of prefabricated vertical drains to the Changi land Reclamation Project, Singapore

The Changi East Reclamation Project in the Republic of Singapore involved the filling of approximately 200 million cubic of sand for the land reclamation of a total area of about 2500 hectares. Land reclamation was carried out using fill materials obtained from dredging granular material from the seabed at the borrow source. The ground improvement technique which involved combination of prefabricated vertical drain (PVD) with preloading was successfully applied in this project to improve the underlying compressible soils. The project comprises the installation of prefabricated vertical drains and the subsequent placement of surcharge to accelerate the consolidation of the underlying marine clay. In order to monitor the performance of ground improvement and to validate the performance of the prefabricated vertical drain system, several geotechnical instruments were installed to monitor the degree of consolidation at both area with PVD and area without PVD as control area. This paper provides a case study of the ground improvement works carried out with prefabricated vertical drains at the Changi East Reclamation Project and their subsequent performance assessment.