| Autor: |
Raby AC; School of Engineering, University of Plymouth, Drake Circus, Plymouth PL4 8AA, UK., Antonini A; Department of Hydraulics Engineering, Delft University of Technology, 2628 CN Delft, The Netherlands., Pappas A; Civil, Environmental and Geomatic Engineering, UCL, Gower Street, London WC1E 6BT, UK., Dassanayake DT; School of Engineering, University of Plymouth, Drake Circus, Plymouth PL4 8AA, UK., Brownjohn JMW; College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter EX4 4QF, UK., D'Ayala D; Civil, Environmental and Geomatic Engineering, UCL, Gower Street, London WC1E 6BT, UK. |
| Abstrakt: |
Lighthouses situated on exposed rocky outcrops warn mariners of the dangers that lurk beneath the waves. They were first constructed when approaches to wave loading and structural response were relatively unsophisticated, essentially learning from previous failures. Here, we chart the evolution of lighthouses on the Wolf Rock, situated between Land's End and the Isles of Scilly in the UK. The first empirical approaches are described, followed by design aspects of the present tower, informed by innovations developed on other rocky outcrops. We focus on a particular development associated with the automation of lighthouses: the helideck platform. The design concept is described and the structure then scrutinized for future survivability, using the latest structural modelling techniques of the entire lighthouse and helideck. Model validation data were obtained through a complex logistical field operation and experimental modal analysis. Extreme wave loading for the model required the identification of the 250-year return period wave using a Bayesian method with informative prior distributions, for two different scenarios (2017 and 2067). The structural models predict responses of the helideck to wave loading which is characterized by differential displacements of 0.093 m (2017) and 0.115 m (2067) with associated high tension forces and plastic strain. This article is part of the theme issue 'Environmental loading of heritage structures'. |
