High-resolution time-dependent probabilistic assessment of the hydraulic performance for historic coastal structures: application to Luarca Breakwater

Abstract

Historic coastal structures have played a key role in small- to medium-size ports, being the driving force for the local development of coastal communities. Because coastal managers require reliable risk-based analysis of the whole life cycle of these coastal structures, previous lifetimes should be studied. This is a differentiating factor with respect to the newly built breakwaters. For this reason, in this work, a methodology for assessing how the hydraulic performance of an expired lifetime has evolved over the years is presented. It is performed following a probabilistic approach due to the uncertainty related to both the involved variables (wave climate, geometrical and structural breakwater variables) and the hydraulic response of the structure. The first ones are characterized by reliable probability distribution functions. The second ones are characterized by reliable formulae for the analysis of the hydraulic response. However, their non-conventional designs located in shallow-water locations require site-dependent formulae. To overcome this problem, a novel methodology to apply CFD numerical models is presented. Finally, it is integrated in a high-resolution time-dependent probabilistic methodology which takes into account the stochastic behaviour of all the involved variables, coastal and structural processes with a good uncertainty level. This article is part of the theme issue ‘Environmental loading of heritage structures’.

Environmental loading of heritage structures

“…The field monitoring on La Jument determined natural frequencies and damping coefficients of the structure during a dramatic wave impact [4]. The stereo imaging technique that has been described in La Jument [3] is also being implemented on Wolf Rock lighthouse this summer, with expert advice from Alvise Benetazzo one of the paper co- More generic heritage coastal structures have been included in this special issue, as it features the historic Luarca breakwater in Spain [10]. Away from the coastal zone, and experiencing significant wind loading, two unusual heritage structures are investigated: masonry chimneys in Portugal [11] and steel transporter bridges in the UK [12].…”

“…The versatility of the Bayesian method is reflected in the applications present in this issue: Bartoli et al [13] use a Bayesian model updating framework with probabilistic structural analyses leading to fragility curves for seismic loading and Raby et al [1] use a Bayesian method with informative prior distributions to consider how the wave climate may change 50 years into the future at the Wolf Rock and show the potential implications on the lighthouse. Finally, a time-dependent contemporary probabilistic design approach is applied to the Luarca breakwater in Spain by Lara et al [10], showing how the structure serviceability and stability have been evolving over time in a context of uncertainty.…”

Catania Harbor Breakwater: Physical Modelling of the Upgraded Structure

“…Great part of the historical coastal and harbor defense structures is in shallow-waters and consists of non-conventional breakwaters, which have been repeatedly modified over the years and usually converted into rubble mound structures (Lara et al 2019). Therefore, traditional empirical design formulae defined for new structures may be not able to properly characterize the hydraulic behavior of both damaged and restored breakwaters, whose actual composition in terms of material and layers geometry is often unknown, because of the lack of documents and reports regarding the modifications implemented during their lifetime.…”

“…In addition, some investigations on implemented restoration projects are available, that however only describe the design procedures, without defining formulae or models suitable for the design of upgrading options or testing the applicability of the traditional state-of-art design equations (Jensen et al 2018;Ligteringen et al 1993;Main et al 2018;Santos-Ferreira et al 2015). As regards the available numerical models, they have not been sufficiently calibrated to simulate all the common restoration concepts, particularly concerning the stability of the armor layer (Burcharth et al 2014;Lara et al 2019). As a consequence, physical modelling represents the most reliable approach to describe the response of existing or upgraded rubble mound structures and their possible failure modes (Burcharth et al 2014;Croeneveld et al 1984;Lara et al 2019;Foti et al 2020).…”

“…As regards the available numerical models, they have not been sufficiently calibrated to simulate all the common restoration concepts, particularly concerning the stability of the armor layer (Burcharth et al 2014;Lara et al 2019). As a consequence, physical modelling represents the most reliable approach to describe the response of existing or upgraded rubble mound structures and their possible failure modes (Burcharth et al 2014;Croeneveld et al 1984;Lara et al 2019;Foti et al 2020).…”