—This paper presents a case study of a conceptual breakwater design to address wave overtopping experienced at the Churchill Barrier No. 2, in the Orkney Islands, UK.
Four approaches to size armourstone have been investigated to account for uncertainty within nearshore wave estimates. A deterministic design approach combined with a joint probability analysis resulted in a stable rock armour weight of 9 tonnes. The use of an ultimate limit state based the unlikely scenario of a 200-year wave, water level and 95th percentile climate change estimate occurring simultaneously resulted in rock armour of 13 tonnes. The use of a probabilistic design incorporating partial safety factors resulted in rock armour of 20 tonnes. The use of Monte Carlo approach indicated an armour weight of 12 tonnes would capture 95% of the uncertainty within simulated 200-year extreme events, which is supporting the ultimate limit state calculations.
—Breakwater, probabilistic design, rock armour.
The authors are with JBA Consulting, Broughton Hall, Skipton, UK (e-mail: email@example.com, firstname.lastname@example.org).
Cite:Daniel Rodger and Josh Harris, "Reducing Design Risk for a Nearshore Breakwater in the Orkney Islands," International Journal of Environmental Science and Development vol. 5, no. 5, pp. 479-483, 2014.