Experiments by Invited Researchers


Large scale experiments for an alternative erosion control measure using sand-filled geosystems

Project acronym: H+-UPC-03-CIEM
Name of Group Leader: Adam Bezuijen
User-Project Title: Large scale experiments for an alternative erosion control measure using sand-filled geosystems
Facility: CIEM
Data Storage Report: data_report_geos.pdf

Large scale model test on sand-filled geosystems for coastal protection (GEOS)

Adam Bezuijen, Luciana Das Neves, Ivàn Caceres, Altomare Corrado,
Tomohiro Suzuki

Large scale model tests have been performed on a scale 1:5 in the ICTS-CIEM to test the stability of sand-filled geosystems, both tube and bags, and their effect on the morphological evolution of a beach profile. Tube and bags were buried in sand at the upper part of a beach profile with a slope 1:15 in the area where it was transitioning to a beach berm (horizontal flat section). Erosion of the beach during the experiment exposes the tube and bags to direct wave attack. Tests were done under the action of irregular waves with a significant wave height of 2.5 m in prototype. Also, the effect of two different water levels was considered.

The main objective of this project is: to evaluate the sand filled elements (SFE, tubes and bags) with respect to coastal protection and risk reduction by studying its influence on morphological changes in the coastal zone under storm wave conditions through large scale physical model testing.

Under the conditions tested, the erosion at the seaward side of the tube and bags was limited. Remarkable there was more erosion around the bags. As a consequence of the limited erosion, the stability of the structure was never a problem.

The tests indicate that an SFE dune toe protection is feasible. However, the tests described here are only a first indication. As mentioned, the erosion was limited, also the influence of tide and longshore current was not tested. However, the stability of the SFE structures and that, within the limits of testing, the influence of the water level is limited are promising results.

Figure 1. Sand filled bags installed in the beach profile.


Figure 2. Tube in the beach profile at the beginning of test.


Figure 3. Erosion profiles after 14 hours of testing with a water level equal to the top of the tubes or bags (P31 and P64) or 20 cm lower (P48) (model dimensions)