Civil Engineering and Architecture 13(3): 1668-1676, 2025 http://www.hrpub.org DOI: 10.13189/cea.2025.130317 Fin Gabions: A Solution for River Bend Stability Mas Mera, Yolanda Wulandari, Junaidi, Februarman * Department of Civil Engineering, Universitas Andalas, Indonesia Received December 19, 2024; Revised February 5, 2025; Accepted March 17, 2025 Cite This Paper in the Following Citation Styles (a): [1] Mas Mera, Yolanda Wulandari, Junaidi, Februarman , "Fin Gabions: A Solution for River Bend Stability," Civil Engineering and Architecture, Vol. 13, No. 3, pp. 1668 - 1676, 2025. DOI: 10.13189/cea.2025.130317. (b): Mas Mera, Yolanda Wulandari, Junaidi, Februarman (2025). Fin Gabions: A Solution for River Bend Stability. Civil Engineering and Architecture, 13(3), 1668 - 1676. DOI: 10.13189/cea.2025.130317. Copyright©2025 by authors, all rights reserved. Authors agree that this article remains permanently open access under the terms of the Creative Commons Attribution License 4.0 International License Abstract River bends are susceptible to sedimentation near the inner bend and erosion near the outer bend due to uneven velocity distribution. This study investigates the effectiveness of fin gabions in mitigating these issues through physical modeling. Five experimental setups were conducted in a laboratory flume: (1) Baseline: A leveled sand bed with regular gabions placed on the outer bend; (2) Lower Fin Gabion: A fin gabion embedded at the lower part of the bend. This setup addresses topography issues encountered in post-simulation of setup 1; (3) Mid-Bend Fin Gabion: An additional fin gabion embedded at the middle of the bend. Topography challenges in post-simulation of setup 2 necessitated this configuration; (4) Reinstalled Gabions: Reinstallation of all gabions from setup 3. This setup is implemented to ensure that the gabion configuration in setup 3 can maintain the baseline without changing significantly; and (5) Surface-Placed Gabions: All gabions placed on the surface without embedding. This setup aims to ensure that the fin gabions are firmly embedded. Results demonstrate that the fin gabion configurations, especially setup 3, significantly reduced sedimentation near the inner bend by up to 72%. This reduction led to a more uniform flow distribution, mitigating erosion at the outer bend. The findings highlight the potential of fin gabions as an effective solution for enhancing river bend stability. Keywords Fin Gabion, Erosion, Sedimentation, Inner Bend, Outer Bend 1. Introduction River bends are prone to sedimentation near the inner bend and erosion near the outer bend due to uneven velocity distribution [1]. The higher velocity near the outer bend leads to erosion and potential bank collapse [2]. Similar issues can arise around bridge pillars [3]. While rainfall can exacerbate erosion, especially during extreme events, the most severe erosion often occurs at the ends of the bend [4]. Bank protection structures like gabions are particularly vulnerable at these locations, with the lower end experiencing more rapid damage [5]. Gabions are often chosen due to their economic efficiency and effectiveness [6, 7]. In addition to their role in bank protection, gabions are also employed as weir structures [8]. Conversely, the lower velocity near the inner bend promotes sedimentation. The severity of both sedimentation and erosion is influenced by the bend angle, with sharper bends leading to more pronounced effects. In sloping areas, factors like rainfall, topography, land use, and soil type also contribute to sedimentation [9-11]. The combined impact of these factors can lead to the failure of gabion structures [2]. While gabions are commonly used for bank protection, Hasan and Toda explored the use of groins in meandering rivers [12]. Numerical simulations indicated that cross-bar groins, extending from the bank to the river's mid-channel, can inadvertently increase erosion risk. This research objective is to control sedimentation near the inner bend of a flume bend by utilizing fin gabions attached to regular gabions on the outer bend. While both types of gabions have identical dimensions, their distinct placements within the flume result in different functions. The hypothesis is that fin gabions can effectively alter the flow velocity distribution, shifting it from the outer bend towards the inner bend. This present research employs physical modeling to simulate sedimentation and erosion