Probabilistic Design of River Jetties by Monte Carlo Simulation

The design of coastal structures is inherently associated with multiple sources of uncertainty, among which the design wave height constitutes the most significant parameter. When the design wave height, determined through statistical methods, is directly substituted into the Hudson formula, the resulting design is based on a single deterministic value. However, under identical environmental conditions, the design wave height may exhibit considerable variability. Consequently, the adoption of a probabilistic design approach, rather than a purely deterministic one, becomes essential to ensure an adequate level of structural safety. Within the scope of this study, probabilistic design analyses were conducted using the Monte Carlo Simulation (MCS). The Monte Carlo Simulation of the Hudson Limit State Function facilitates the probabilistic design of jetties by explicitly accounting for uncertainties inherent in the governing parameters. The primary advantage of this approach lies in its capability to systematically evaluate uncertainties affecting the structure — particularly variations in the design wave height under design conditions — and to estimate the structural reliability more realistically and robustly. For the probabilistic assessment, a total of 30,000 simulations were performed by assigning appropriate probability distributions to key uncertain parameters, including the design wave height. The results obtained were found to agree with the design standard developed by Det Norske Veritas (DNV) in 1992 for marine structures, which specifies a target reliability level of 10⁻³. The reliability indices derived from the MCS exceeded this threshold, indicating that the proposed design approach achieves a higher level of structural safety. The findings of this study clearly demonstrate that probabilistic design represents the most reliable and rational solution for designing coastal structures, which are characterized by substantial inherent uncertainties arising from their environmental and operational conditions. In this context, incorporating probabilistic design methodologies into the regulatory frameworks of governing authorities responsible for coastal structure design is crucial. Within the scope of the study, the wind and wave climates of the case study were obtained using the HYDROTAM-3D model.