An experimental study on the performance of geotextile tubes in beach nourishment applications

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Thesis Type: Postgraduate

Institution Of The Thesis: Middle East Technical University, Graduate School of Natural and Applied Sciences, Turkey

Approval Date: 2019

Thesis Language: English

Student: EMRECAN IŞIK

Supervisor: Cüneyt Baykal

Abstract:

In this study, performance of submerged geotextile tubes as toe protection for the beach nourishment applications was investigated through physical model tests. Crossshore sediment transport volumes and sand protection performances of geotextile tubes were evaluated based on the measured post-storm beach profile changes and recessions or progressions of shoreline. In the experiments, the effects of fill material sediment grain sizes, fill angles, negative freeboards of geotextile tubes, and wave steepnesses were investigated. According to the profile measurements, the increase in the significant wave height and wave steepness were found as augmentative factors of beach erosion. It was observed that the increase in sand grain diameter reduces the sediment movement in nearshore, while steepening of the fill angle strengthened the effect of the erosive and accretive waves. It was also observed that using tubes as toe protection in beach nourishment applications in wave breaking zone did not have positive effects on recessions or progressions, instead geotextile tubes placed outside of breaking zone as submerged breakwaters worked more efficient.