Dimensionless wave height parameter for preliminary design of scour protection in offshore wind farms

Abstract

Matutano, C., Negro, V., López-Gutiérrez, J.S., Esteban, M.D. and del Campo, J.M, 2013. Dimensionless wave height parameter for preliminary design of scour protection in offshore wind farmsThe scour phenomenon jeopardizes the operating capacity of offshore structures since it compromises their stability. The study of this phenomenon in the field of offshore wind farms began few years ago. Considering that these structures are subjected to waves, currents and tides.This article describes the results of an investigation aimed at the analysis methods used in the design of the protections against scour phenomenon on offshore wind farms in transitional waters, using medium and large diameter monopile type deep foundations.In order to do this, a thorough review of those premises was performed, from one of the first experiences in 1991 (Denmark), to the recently implemented and proposed in the UK, defining its main characteristics (acting maritime climate, the correlation between wave height and period associated with a given recurrence) and the type of protection used (weight average, nominal diameter in the case of breakwater type protection, width and behavior).Taking into consideration the experience with offshore wind farms in current operation, the design data analysis, the basis of climate and the soil-structure interaction, the dimensionless wave height parameter (H0), the erosion extension (Lext), and the quantification of maximum scour depth (Smax) have been calibrated for a preliminary design of protections around a large diameter pile, obtaining initial values for H0 in the vicinity of 6 and 15, and values for the extension of protection design between L/4 and L/2.