Finite element modelling of marine clay deformation under reclamation fills

The ongoing Changi East Reclamation Project in Singapore consists of land reclamation and ground improvement of the foreshore for the future expansion of Changi International Airport. The deformation behaviour of marine clay under reclamation fills and surcharge was modelled by the finite element method (FEM) with Plaxis numerical modelling software. The analyses included modelling the consolidation behaviour of marine clay under reclamation fills with and without prefabricated vertical drains. Marine clay with vertical drains was modelled by both the axisymmetric unit cell and full-scale analysis methods. Marine clay that was not treated with prefabricated vertical drains was modelled by means of full-scale analysis. The numerical analysis was carried out at two case study locations: the pilot test site and the in situ test site. The test sites comprise vertical drain treated and untreated sub-areas that were reclaimed and preloaded under the same conditions. The result of the FEM analysis was compared with that obtained by means of observational methods. The vertical drain performance was verified for the in situ test site by using the value of Ch obtained from back-analysis by the Asaoka method and by FEM with Plaxis.