Embedded rocking measurement of single layer armour units

Embedded rocking measurement of single layer armour units: Development and first results

Houtzager, Daan (Student TU Delft; Reefy)
Hofland, Bas (TU Delft Hydraulic Structures and Flood Risk; Deltares)
Caldera, Ganga (Student TU Delft; Delta Marine Consultants)
van der Lem, Cock (Royal HaskoningDHV)
van Gent, M.R.A. (TU Delft Coastal Engineering; Deltares)
Bakker, Pieter (Delta Marine Consultants)
Antonini, A. (TU Delft Coastal Engineering)

2023

Randomly placed breakwater armour units under wave loading can sometimes start rocking, which can lead to breakage of armour units. This failure mechanism can especially become important for single layer randomly placed armour units for which full displacement of units will only happen at higher stability numbers compared to older types of units, and where unit breakage can more easily lead to progressive damage to the armour layer. However, unlike older types of units, hardly any quantitative information is available on the impact velocities, and the number of impacts is mostly assessed using somewhat subjective visual observations. In design the observed number of rocking units is limited to the amount of visually observed rocking units. Hence a good quantification of impact velocities could lead to a more optimal design. This paper describes the further development of embedded rocking sensors to measure the motions of individual smart armour units. Multiple smart rocking sensors have been applied in a physical model of a breakwater and measurements were collected to determine the number of impacts and impact velocity of the armour units. The results have been compared to visual observations and the first results will be presented. It is concluded that the new technique can be used to obtain much more information on rocking, including impact velocities, and that more rocking occurs than is observed visually.

http://resolver.tudelft.nl/uuid:88317cb3-aa42-4bce-9bd3-c9e1b3d3f8d7

Institution of Civil Engineers

2023-10-27

Procedings ICE Breakwaters conference 25-27 April 2023

ICE Breakwaters 2023, 2023-04-25 → 2023-04-27, Portsmouth Marriott Hotel, PO6 4SH, Portsmouth, United Kingdom

Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.

Institutional Repository

conference paper

© 2023 Daan Houtzager, Bas Hofland, Ganga Caldera, Cock van der Lem, M.R.A. van Gent, Pieter Bakker, A. Antonini