Large Deformation Finite Element Modeling of Rubble Mound Breakwater Built on Soft Seabed Using Coupled Eulerian–Lagrangian Method

Abstract

For the design of rubble mound breakwaters on soft soil, it is essential to predict the behavior of soft soil and large deformations phenomena occurring in the course of construction of the rubble mound breakwater. Large deformations in various problems can be well simulated using the coupled Eulerian–Lagrangian (CEL) method. In this study, the CEL method has been used to simulate the rubble mounds construction on soft soil and predict the resulting settlements. To validate the numerical model, the results of three experiments conducted in the physical modeling laboratory at Kharazmi University were used. Also, two case studies of real rubble mound breakwaters constructed on soft seabeds were numerically simulated and the results of the numerical model were compared with the recorded data. According to the obtained results, the finite element analysis by the CEL method is able to predict the deformations and settlement occurred during construction of rubble mound breakwaters on soft soils with a reasonable accuracy. In very soft soils with undrained shear strength less than 10 kPa, the CEL simulation outperformed the Lagrangian formulation. Then, parametric study was performed and the effects of height, crest width, breakwater slope and thickness and strength of the soft soil on the amount of rubble mound settlement were investigated.