Influence of the Spatial Pressure Distribution of Breaking Wave Loading on the Dynamic Response of Wolf Rock Lighthouse

Journal article (2021)

Authors

Darshana Dassanayake University of Plymouth, University of Sri Jayewardenepura
A. Antonini Coastal Engineering - CEG
Athanasios Pappas University College London
Alison Raby University of Plymouth
James Mark William Brownjohn University of Exeter
Dina D’Ayala University College London
Research Group
Coastal Engineering (CEG) (TU Delft)
Copyright: © 2021 Darshana T. Dassanayake, A. Antonini, Athanasios Pappas, Alison Raby, James Mark William Brownjohn, Dina D’Ayala
DOI: https://doi.org/10.3390/jmse9010055
More Info
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Published Date

2021

Language

English

Faculty

Civil Engineering & Geosciences

Department

Hydraulic Engineering

Research Group

Coastal Engineering

Abstract

The survivability analysis of offshore rock lighthouses requires several assumptions of the pressure distribution due to the breaking wave loading (Raby et al. (2019), Antonini et al. (2019). Due to the peculiar bathymetries and topographies of rock pinnacles, there is no dedicated formula to properly quantify the loads induced by the breaking waves on offshore rock lighthouses. Wienke’s formula (Wienke and Oumeraci (2005) was used in this study to estimate the loads, even though it was not derived for breaking waves on offshore rock lighthouses, but rather for the breaking wave loading on offshore monopiles. However, a thorough sensitivity analysis of the effects of the assumed pressure distribution has never been performed. In this paper, by means of the Wolf Rock lighthouse distinct element model, we quantified the influence of the pressure distributions on the dynamic response of the lighthouse structure. Different pressure distributions were tested, while keeping the initial wave impact area and pressure integrated force unchanged, in order to quantify the effect of different pressure distribution patterns. The pressure distributions considered in this paper showed subtle differences in the overall dynamic structure responses; however, pressure distribution #3, based on published experimental data such as Tanimoto et al. (1986) and Zhou et al. (1991) gave the largest displacements. This scenario has a triangular pressure distribution with a peak at the centroid of the impact area, which then linearly decreases to zero at the top and bottom boundaries of the impact area. The azimuthal horizontal distribution was adopted from Wienke and Oumeraci’s work (2005). The main findings of this study will be of interest not only for the assessment of rock lighthouses but also for all the cylindrical structures built on rock pinnacles or rocky coastlines (with steep foreshore slopes) and exposed to harsh breaking wave loading.