Development of Load and Resistance Factors for the Reliability based Design of Harbor Facilities

In this study, a Load and Resistance Factor Design (LRFD) method applicable to gravity-type port structures (caisson composite breakwaters and caisson-type quay walls) was developed based on probabilistic reliability analysis methods. To this end, representative domestic design cases distributed across all coastal areas of the East, West, and South coasts were systematically collected and analyzed to evaluate the quantitative failure probability levels for each limit state of the structures. A reasonable target reliability index was established by comprehensively considering the consistency between the results of intrinsic safety margin analyses of existing structures and the reliability indicators of domestic and international design codes. Based on this, code calibrations using the First Order Reliability Method (FORM) and Monte Carlo Simulation (MCS) were performed to determine the optimal load and resistance factors. Applying the proposed load and resistance factors enables the implementation of a rational limit-state design that consistently satisfies the target reliability levels in both structure stability and subgrade design; this is expected to contribute as an advanced technical and academic standard for future revisions to Korea’s reliability-based port design codes.