A stochastic numerical model for wave-induced dynamic response in a spatially heterogeneous seabed around structures

Abstract

The interaction between waves, seabed, and structures is a complex phenomenon that involves multiple physical domains and processes. The spatial variability of properties in marine sediment can significantly affect the dynamic response of seabed. A stochastic numerical model is developed to investigate the response in a spatially heterogeneous poro-elastic seabed around a submerged breakwater. The model is implemented using the COMSOL platform, which allows for solving the wave and seabed sub-models within the same framework. The spatial variability of soil properties is simulated using the random field method employing the Karhunen-Loève expansion. To couple the generated random fields in MATLAB with the integrated model in COMSOL, a LiveLink program is developed, which incorporates a cycle algorithm for stochastic finite element analysis, enabling hundreds or thousands of runs. The model is validated by comparing its results with analytical solutions and experimental data from literature. Probabilistic analysis is performed using the stochastic numerical model and Monte Carlo simulations. The effects of coefficient of variation and correlation lengths in random field on the probabilistic analysis are investigated. The present study provides a valuable tool and insights for the probabilistic assessment of soil response in a spatially heterogeneous seabed around structures.