Numerical Analysis of the L-Shaped Caisson Quay Wall on Sandy Soil

Abstract The L-shaped caisson has been extensively utilized in marine infrastructure projects, particularly for deep-water ports and artificial islands. Numerical studies were conducted in this article to investigate the deformation and stability of the L-shaped caisson quay wall on sandy soil under live load. The accuracy of the numerical model was validated by the laboratory model tests in the literature. Parametric studies were conducted to examine the effects of caisson dimensions, live loads, and backfill soil properties on the stability of the L-shaped caisson quay walls. It is found that the heel length of the L-shaped caisson, the loading distance and width of the loading plate, and the effective friction angles of the soil heavily influence the stability and deformation of the L-shaped caisson quay wall. The horizontal displacements decreased by 49% with increasing heel length and by 92% with increasing loading distance. Four failure modes can be categorized based on the shapes and numbers of failure surfaces generated in the sand backfill. A method for determining failure modes was developed based on a statistical analysis of 130 numerical simulation cases. The predictive accuracy of the proposed classification criteria was verified to be 94% for the failure Mode I, 77% for Mode II, and 82% for Mode III.