Performance Analysis of Vertical Breakwaters Designed by Partial Safety Factor Method

Kim, S.-W. and Suh, K.-D., 2013. Performance analysis of vertical breakwaters designed by partial safety factor method In: Conley, D.C., Masselink, G., Russell, P.E. and O'Hare, T.J. (eds.), Proceedings 12 th International Coastal Symposium (Plymouth, England), Journal of Coastal Research, Special Issue No. 65, pp. 296-301, ISSN 0749-0208. The partial safety factor method has been developed in Europe, Japan, and Korea to overcome the limitations of the deterministic method for design of the vertical breakwater. The practical engineers prefer the partial safety factor method because this method is relatively simple to use compared with other probabilistic methods. However, the partial safety factor method does not evaluate the displacement of the vertical breakwater, while only defining the boundary between safety and failure domains within a given target safety level. Therefore, it is required to examine the performance of the breakwater designed by the partial safety factor method in terms of caisson sliding distance. In the present study, the partial safety factors developed by an advanced research for vertical breakwaters are used with the target reliability indices of 2.33 and 2.0. The performance analysis of 12 cross-sections of five vertical breakwaters was conducted by the method based on the Monte-Carlo simulation. Especially, this method considers a technique to eliminate the unrealistic extreme values of the design variables. As a result, the breakwaters designed by the partial safety factor method with the target reliability index of 2.0 are found to be stable except for one cross-section with high uncertainty of wave height. On the other hand, all the breakwaters with the reliability index of 2.33 are found to be stable irrespective of any uncertainty of wave height. Finally, it is found that the vertical breakwaters designed with the reliability index of 2.33 satisfy the allowable exceedance probabilities for both repairable and ultimate limit states.