Target reliability of caisson sliding of vertical breakwater based on safety factors

Abstract

This paper presents two methods that evaluate the target reliability of caisson sliding of a vertical breakwater. First, the statistical characteristics and probability density function are obtained for the safety factors of the breakwaters designed by deterministic methods in the past. The first method calculates the probability density of reliability index by applying the Monte Carlo simulation to the safety factor for various combinations of uncertainties of load and resistance. The significant target reliability index is then calculated by averaging the highest one third of the reliability index. The second method uses the Chebyshev inequality which describes the lower limit of reliability index. Again the Monte Carlo simulation is used to calculate the probability density of the lower limit of reliability index. The maximum of the possible lower limits is then taken as the target reliability index. The application of the methods has given the target reliability indices close to one another and also close to the value used in a recently published design standard.