Sustainable Marine Structures

In recent decades, previous studies have measured the deformation of piled-raft foundations, yielding reliable results. However, researchers have not studied raft foundation deformation as thoroughly, particularly in coastal marine clay soils frequently subjected to sea-level fluctuations and saline inundation. In this study, the authors measured the settlement and deformation of marine clay soil beneath a raft foundation where variations occur in groundwater level. The study investigates the vertical settlement behavior of marine clay ground beneath a raft foundation under different groundwater levels (GWLs). Laboratory tests conducted according to Vietnamese Standards (TCVN) and a numerical method (PLAXIS 3D) were used to simulate vertical settlement (deformation) and the groundwater-level conditions at depth. Both experimental and simulation results show that the maximum settlement reached 20.77 cm at a GWL depth of 22.3 m under a loading of 800 kN/m². Moreover, the results include the deformation modulus (K_deformation), cohesion (K_cohesion), Young's modulus (K_Yelastic), shear resistance (K_{shear resistance}), the vertical displacement (K_dis), pore water pressures, and other parameters, which are shown partially at the depths where the clay ground is located near the coastal regions. The study's findings provide valuable references for the fields of geotechnical engineering, infrastructure construction, and underground works in the future.