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The paper presents results of numerical analysis of the gabion retaining wall stability. A real, complicated object is analysed. Gabions are modelled using a homogenized Mohr-Coulomb model for mesh and filling. Interface elements are used to allow discontinuous deformation field between adjacent gabions and between gabions and subsoil. A parametric study of the influence of the mesh and joints between gabions strength on the stability of the structure is performed. Different modelling approaches are compared. Numerical simulations were performed using ZSoil v25 Finite Element Method (FEM) system. Efficiency of the proposed approach is shown.

River banks protection is one of the most significant challenges due to the impact of flowing ‎water and the erosion caused. The accurate estimation of morphological changes due to the generated scour around environmentally friendly spurs, such as gabion spurs is crucial for sustainable and safe hydraulic design. This study aims to analyze the effect of different grades of median gravel size (d mg = 15, 27, and 45 mm, for grade 1, 2, and 3 respectively) of rectangular gabion spurs on the scour hole characteristics under clear water condition by experimental investigation. The experiments were conducted in horizontal laboratory flume with non-cohesive sand (d 50   =  0.72 mm) for varied ranges of flow intensity ( 0.5 ≤ V/Vc ≤ 0.998) and flow depth (7 and 10 cm). For tested gabion spurs, when the size of median gravels diameter decreases, it was found that the scour hole dimensions increase ‎as intensity of flow increases. According to the experiments results, the maximum relative scour (d s /y) equals to 1.886, 1.786, and 1.657 for grade1, 2 and 3 respectively. Furthermore, a comparisons have been characterized for the effect of the influence parameters such a flow intensity, and Fraud’s number on the morphological scour hole around modelled gabions spurs. According to the extracted results of the present study and based on dimensional analysis ‎technique and statistical indicators, new validated empirical formula has been presented to estimate the scour depth near gabion ‎spurs utilizing multiple nonlinear regression. Finally, findings underscore that gabion spurs with finer gravel require careful design to mitigate excessive scour, while the formula provides a practical tool for optimizing erosion control in river engineering.

Lee, B.W.; Yoon, J.-S.; Ko, D., and Song, H.-G., 2023. Optimization of structural scales for ripraps and gabions at seadike closure. In: Lee, J.L.; Lee, H.; Min, B.I.; Chang, J.-I.; Cho, G.T.; Yoon, J.-S., and Lee, J. (eds.), Multidisciplinary Approaches to Coastal and Marine Management. Journal of Coastal Research, Special Issue No. 116, pp. 6-10. Charlotte (North Carolina), ISSN 0749-0208. This paper presents the results of a long-term hydraulic experiment examining the fabricated ripraps and gabions used in the construction of the final closure on the Saemangeum seadike. While focusing on a sill-crest, a bottom protection, and a dam face, the critical velocities were measured at different cross-sections in this experiment. Due to limitations in terms of the size and volume of ripraps that could be collected on-site for this experiment, an alternative study was conducted to compare the critical velocities of fabricated gabions with those of ripraps. Moreover, critical velocities were measured in cases where ripraps and gabions were used together. Based on the above investigations, this study provides suitable mixing ratios for gabions in cases where the sizes and critical velocities of ripraps are insufficient. Critical velocities were obtained from data for previously predicted daily and hourly velocities during the construction of the final closure. Further, riprap sizes were provided for different water depths with consideration of the changes in water depth caused by the construction. As a result, losses of materials (i.e., ripraps and gabions) were minimized during the construction, and this study could contribute to the final closure on the Saemangeum seadike.

The current study used the genetic programming technique to re-analyze the data of the classical shape of the gabion baskets in a trial to find the best solution to represent the energy dissipation term of this type of hydraulic structures. For that, the resulted data from using five different gabion baskets with different filling materials put respectively within a flume channel with a range of discharges between (0.7 − 15.0 l/s) were tested using the “GeneXproTools 5.0” computer program, and compare the resulted formulas by those formulated previously by the non-linear regression analysis. The conclusion of this study approved the fact that using of the genetic programming technique gives a flexible treatment in analyzing the resulted data of the experimental works especially for this type of hydraulic structures, whereas the used technique gave a mathematical expression of the raw data of the experimental work with an acceptable solution compared by the solutions of the former used technique. Keep changing the ratio of both the training and validation data is the better way to achieve the best solution, whereas the ratio of (60% training:40% validation) gave higher value of R2 equal to 0.94 compared by that for non-linear regression analysis, but the resulted formulas of the gabion baskets for all cases showed a complex expression compared by those resulted from the non-linear regression analysis of the literature studies, and that probably make the manual field application goes difficult compared by the direct analysis style. Although, all the resulted formulas of the gabion baskets by the used technique showed high accuracy validation values which make them acceptable for design and future development purposes of this kind of weirs.

To reveal the mechanical behavior and deformation patterns of geotechnical reinforcement materials under tensile loading, a series of tensile tests were conducted on plastic geogrid rib, fiberglass geogrid rib, gabion steel wire, plastic geogrid mesh, fiberglass geogrid mesh, and gabion mesh. The full tensile force–strain relationships of the reinforcement materials were obtained. The failure modes of different geotechnical reinforcement materials were discussed. The standard linear three-element model, the nonlinear three-element model, and the improved Kawabata model were employed to simulate the tensile curves of the various geotechnical reinforcement materials. The main parameters of the tensile models of the geotechnical reinforcement materials were determined. The results showed that a brittle failure occurred in both the plastic geogrid rib and the fiberglass geogrid rib subjected to tensile loading. The gabion steel wire presented obvious elastic–plastic deformation behavior. The tensile resistance of fiberglass geogrid mesh was higher compared to that of plastic geogrid, which was mainly caused by the difference in the cross-sectional areas of these two types of geogrid. Due to a hexagonal mesh structure of gabion mesh, there was a distinct stress adjustment during the tensile process, resulting in a sawtooth fluctuation pattern in tensile curve. Compared to the strip geogrid material, hexagonal-type gabion mesh could withstand higher tensile strain and had greater tensile strength. Brittle failure occurred in both the plastic geogrid rib and the fiberglass geogrid rib when subjected to tensile loading. The gabion steel wire presented obvious elastic–plastic deformation behavior. The standard linear and nonlinear three-element models as well as improved Kawabata model could all well reflect the tensile behavior of geotechnical reinforcement materials before the failure of the material.

The interface friction mechanics of reinforcement material with filler is an essential issue for the engineering design of reinforced soil structure. The interface friction mechanics is closely associated with the properties of filler and reinforcement material, which subsequently affects the overall stability. In order to investigate the interface mechanism of a double-twisted hexagonal gabion mesh with a coarse-grained filler derived from a weathered red sandstone, a large laboratory pullout test was carried out. The pullout force–displacement curve was obtained by fully mobilizing the gabion mesh to reach the peak shear stress at the interface between the gabion mesh and the coarse-grained filler. The change of force–displacement characteristics and the distribution of tensile stress in gabion mesh during the pullout process were obtained. A 3D numerical model was established based on the pullout test model, and the model for analyzing the interface characteristic between the gabion mesh and the coarse-grained filler was modeled using the FLAC3D 6.0 platform. The interface characteristics were further analyzed in terms of the displacement of soil, the displacement of reinforcement, and the shear stress of soil. The strength and deformation behaviors of the interface during the entire pullout process were well captured. The pullout force–displacement curve experiences a rapid growth stage, a development transition stage and a yielding stabilization stage. The critical displacement corresponding to peak pullout stress increases with the increase in normal stress. The normal stress determines the magnitude of shear stress at the reinforcement and soil interface, and the displacement distribution of a gabion mesh is not significantly affected by normal stress when the applied normal stress is within a range of 7–20 kPa. The findings are beneficial to engineering design and application of a gabion mesh-reinforced soil structure.

The work considers the use of gravitational retaining walls made of gabion structures to strengthen the sea slopes. A wide range of possibilities for using gabions in construction is noted. An analysis of the technical and regulatory literature leads to the conclusion that the issue of using gabion structures to strengthen marine coastal slopes is not well understood. The paper describes the experience of using gabions to strengthen and protect against erosion of the sea slope from the moment of creation to complete destruction. A change in the state of the structure during long-term operation and their causes are recorded.

Although gabion has been utilized in geotechnical engineering fields, research on its failure mechanics lags behind its practical applications due to the discrete nature of its mechanical behavior and the multiple factors. Leveraging uniaxial compression testing, this study compares and analyzes the disparities in failure patterns and mechanical characteristics of gabion elements. The deterioration of gabion elements predominantly exhibits in the form of crushing of the rockfill and the fracturing of the gabion mesh. The undulating nature of the load-ACR curve throughout the loading procedure stems from the continual reconfiguration of the contact force chain among the rockfills. Notably, gabion elements possess exceptional ductility, retaining a substantial load-bearing capacity even under significant deformation conditions. The intricate relationships between experimental mechanics, the external gabion mesh, and the internal rockfill are elucidated. It was found that gabion elements exhibit the highest deformation modulus and peak strength when they feature smaller gabion mesh side lengths, larger rib diameters, higher rockfill strengths, and natural rockfill gradation. Furthermore, the crushing of the rockfill and the failure patterns of the gabion mesh are intricately linked to the strength of the rockfill and the rib diameter. In scenarios where the rockfill strength is substantial, the peak strength of the gabion elements is primarily governed by the rockfill itself. In contrast, under other test conditions, the gabion mesh plays a pivotal role. The order of deformation modulus of gabion elements with different rockfill types is sand pebble > shale > red sandstone. The ultimate failure mechanism of the gabion elements often manifests as the enlargement of mesh openings due to the breakage of mesh ribs, leading to the expulsion of internal rockfill. Notably, gabion elements filled with larger rockfill gradations exhibit the most severe hoop distortions and inferior mechanical properties. Conversely, gabion elements containing sand pebble and natural rockfill size demonstrate superior mechanical characteristics. The methodologies, analytical approaches, and insights presented in this study provide valuable references for selecting gabion structure in practical engineering applications.

The current study focus on the effect of using stepped gabion weir in a laboratory channel on the hydraulic jump distance which form at its toe. A series of 175 operation tests and 25 laboratory experiments were conducted by using a laboratory flume 10 m long, 0.3 m wide, and 0.5 m deep. The tested gabions had different five lengths 0.72 m, 0.84 m, 0.96 m, 1.08 m, and 1.20 m respectively, and the material used to fill the gabions was natural quarry mono graded gravel in five different sample sizes of diameters ranged between (09.5-14.0) mm, (14.0-19.0) mm, (19.0-25.0) mm, (25.0-37.5) mm, and (37.5-50.0) mm. The operation flow rate values ranged between 2.33*10-3 to 50.00*10-3 m3/s/m. Dimensional analysis was used to generate dimensionless parameters, and correlated them using the Buckingham Pi-Theorem. The results of this study showed that the hydraulic jump distance increases by increasing the flow rate value, but increasing the values of both of the gravel sample used and the total length of the weir have an undular effect on the hydraulic jump distance.