Design Criteria for Wave Run-Up on Artificial Islands

Abstract

This paper discusses the design criteria for determining the freeboard height of artificial islands against wave run-up and overtopping. A method based on the overtopped volume of water is proposed. Various types of artificial islands have been used recently in arctic waters for oil and gas exploration purposes because of their economic attractiveness and their ability to resist ice forces. In some regions, ice loads govern the island design freeboard height. In other areas, the design criteria for wave run-up and overtopping can be significant in the island crest height determination. The existing methods for estimating the wave run-up and overtopping are based on experimental data for coastal structures such as seawalls and breakwaters. This paper describes a method to estimate the wave run-up and overtopping on the leeside as well as the exposed side of circular shaped artificial islands. The wave run-up and overtopping is estimated using the proposed method for three islands in water depths of 20, 40, and 60 ft at hypothetical locations in the Beaufort Sea. Both sloped and vertical sided islands were examined. Most of the existing designs for wave run-up have been based on the criteria suggested for breakwaters and seawalls for which themore » structural stability is the main concern. This paper suggests the designer assesses the consequences of wave overtopping; i.e., the effect of overtopped water on the facilities and operations on the island, and the drainage requirement on the island top. Excessive wave run-up and overtopping can cause serious operational difficulties and damage to drilling or production facilities on artificial islands.« less