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New laboratory plate test method is proposed for the determination of geosynthetics performance and efficiency of the interlocking in mechanically stabilized layers. The laboratory equipment and experimental methodology are described in details. Proposed method was tested in a set of trials which are evaluated in the paper. Resulting methodology is based on matrix type of tests evaluation, the matrix is formed by several measured parameters. Experiments executed in the laboratory confirmed that the principle of the method is correct and the methodology can be applied for geogrid performance evaluation of various geogrids.

Geogrids are a class of geosynthetic materials made of polymer materials with widespread transportation, infrastructure, and structural applications. Geogrids are now routinely used in soil stabilization applications ranging from reinforcing walls to soil reinforcement below grade or embankments with increased potential for remote-sensing applications. Developments in manufacturing procedures have allowed new geogrid designs to be fabricated in various forms of uniaxial, biaxial, and triaxial configurations. The design flexibility allows deployments based on the load-carrying capacity desired, where biaxial geogrids may be incorporated when loads are applied in both the principal directions. On the other hand, uniaxial geogrids provide higher strength in one direction and are used for mechanically stabilized earth walls. More recently, triaxial geogrids that offer a more quasi-isotropic load capacity in multiple directions have been proposed for base course reinforcement. The variety of structures, polymers, and the geometry of the geogrid materials provide engineers and designers many options for new applications. Still, they also create complexity in terms of selection, characterization, and long-term durability. In this review, advances and current understanding of geogrid materials and their applications to date are presented. A critical analysis of the various geogrid systems, their physical and chemical characteristics are presented with an eye on how these properties impact the short- and long-term properties. The review investigates the approaches to mechanical behavior characterization and how computational methods have been more recently applied to advance our understanding of how these materials perform in the field. Finally, recent applications are presented for remote sensing sub-grade conditions and incorporation of geogrids in composite materials.

Poorly graded soils pose challenges due to their inconsistent particle sizes. Utilizing recycled waste materials in civil engineering applications offers promising benefits in enhancing soil quality and reducing waste generation. Locally available soil was stabilized with varying percentages of crumb rubber in conjunction with biaxial and 3D geogrid reinforcement separately. The aim was to advocate for the use of this combination as an alternative material for improving the geotechnical properties of poorly graded sands. Large-scale direct shear tests were carried out on soil–crumb rubber samples without geogrid, with biaxial geogrid, and with 3D geogrid. The results revealed that incorporating crumb rubber into soil in combination with geogrid reinforcement significantly improves shear strength parameters up to a certain crumb rubber content (by weight). This enhancement in shear strength is attributed to particle inter-locking, apparent cohesion, and frictional resistance arising from incorporating both, crumb rubber and geogrid reinforcement to the soil specimen and this not only enhances the geotechnical properties but also reduces reinforcement costs, contributing to a sustainable solution that mitigates the detrimental environmental impacts of waste rubber disposal.

The traditional stability analysis method of geogrid reinforced slopes does not consider the effect of lateral swelling, so it is not applicable to reinforced expansive soil slopes. This paper reports a new stability analysis method for geogrid reinforced expansive soil slopes. The additional pullout force of the free zone due to the lateral swelling and the anti-pullout safety factor of each geogrid layer were obtained by ensuring the overall stability of the reinforced slope. The optimum design was carried out to treat an expansive soil cut slope in Hubei Province, China, by changing the spacing and length of geogrid reinforcement. Calculation results show that the additional pullout force caused by lateral swelling has a great influence on the anti-pullout stability of geogrids, and the local stability of the reinforced slope will be overestimated if the swelling effect of soil in the free zone is not considered.

The factors influencing geogrid–soil interface characteristics are critical design parameters in some geotechnical designs. This study describes pull-out tests performed on gravelly soils commonly encountered in the Xinjiang region and reinforced with two types of geogrids. The factors affecting the geogrid–gravelly soil interface properties are investigated with different experimental loading methods (pull-out velocity, normal stress), geogrid types, and soil particle size distributions and water contents. The ultimate pull-out force increases with the normal stress and pull-out velocity. Furthermore, with increasing coarse particle content and water content, the ultimate pull-out force increases and then decreases sharply. Based on these research results, this paper provides reasonable parameters and recommendations for the design and pull-out testing of reinforced soil in engineering structures. In reinforced soil structure design, the grid depth should be increased appropriately, and the coarse particle content of the overlying soil should be between 30 and 40%. During construction, the gravelly soil should be compacted to the maximum compaction at the optimal water content, and the structure should have a reasonable waterproofing system. According to the calculation results of the interface strength parameters, the uniaxial geogrid–gravelly soil interface has a high cohesive force c sg , which should not be ignored in reinforced soil structure design.

Facing the challenges in field monitoring of the mechanical response of geogrids in asphalt pavements, this study integrated two types of Fiber Bragg Grating (FBG) sensors, unarmored and armored, into geogrids using the pillar-stitching technique on industrial warp-knitting production lines. The integrated FBG-geogrid systems were comprehensively evaluated in both wound and flattened configurations, enabling the selection of a sensor type suitable for industrial production. After precise strain calibration, a full-scale field damage test was performed during the construction of the Qu-Gang Expressway in Hebei Province, China. The results demonstrate that the helical steel armor layer significantly enhances the mechanical durability of the FBG sensor. Specifically, the armored sensor maintained stable optical transmission over its entire 60-m length, with an average performance retention rate of 98.86% in the flattened state. Moreover, a strong linear correlation was established between the wavelength shift of the armored FBG sensor and the tensile strain of the geogrids. In contrast, the unarmored FBG sensor underwent irreversible shear deformation during production and contained at least two breakpoints. Additionally, a protection scheme employing fiberglass-reinforced silicone rubber on the hot side and standard silicone rubber on the cold side effectively shielded the sensors from high-temperature and compaction loads during asphalt paving. Consequently, the proposed FBG-geogrid integration method and the corresponding field protection strategy provide technical support for the real-time monitoring of geogrid performance in asphalt pavements and have significant engineering value.

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 soil in Najaf City, an essential religious urban area in Iraq, faces serious challenges due to the presence of gypsum, and this percentage dissolves when the water level rises, causing cavities in the soil; this study highlights this problem. Nineteen model tests were conducted in a laboratory focused on the study of the combined effects on the behavior of the circular anchor plate with a diameter of 15 cm buried in sandy soil with water presence as a static state at a different head level (h =>30, 30, 20, 10, and 0 cm below ground surface of soil or h=0, 30, 40, 50 and 60 cm above the impermeable layer) for model tests without and with cavity with different diameters (10, 15, and 20 cm). The anchor plate is embedded at a constant depth of (H=30 cm) below the ground surface level of the sandy soil. The experimental work also illustrated the effect of the geogrid layer (B=60 cm) placed above the anchor plate in increasing the soil resistance and reducing the vertical displacement. The results show placing the geogrid layer in model tests is very effective for model tests with cavity. Also, the impact of the geogrid layer in submerged model tests is higher than in unsubmerged condition; the magnitude of the treated factor (Tf) for without cavity model test at unsubmerged condition reaches 29.3%, while for the same model test in the submerged condition, the treated factor (Tf) increasing until reaches at 60.82%.

Geosynthetics (GSN) are polymeric products used in Geotechnical Engineering for the purpose of improving the properties of the insitu soil. In this project, experimental work was carried out to determine the influence of presence of fines within granular soil on the CBR strength of soil reinforced with different GSN (Woven geotextile, Non-woven geotextile, Geogrid and Geonet). Two types of granular soil in disturbed state containing varying percentage of fines were selected from in and around the Chennai region. Soil type 1 contains high fines of about 40% (SHF) whereas soil type 2 contains less fines of about 7% (SLF). Unsoaked CBR (U-CBR) test was carried on unreinforced soil and on soil reinforced with different GSN placed at varying depths of D/5, 2D/5, 3D/5 and 4D/5 from top of soil (D is the total depth of soil), to determine the ideal depth of placement of GSN within SHF and SLF. Soaked CBR (S-CBR) test was carried on unreinforced soil and on soil reinforced with different GSN placed at an ideal depth determined from U-CBR test. Based on the experimental results, ideal depth of placement of GSN for SHF and SLF was found to be D/5 and 3D/5 respectively from top of the soil and Geogrid was found to be the best geosynthetic for reinforcing the granular soil containing high fines and less fines.

Geosynthetics are planar polymeric products, which are used in connection with soil, rock or other soil-like materials to fulfill various functions in geoenvironmental engineering. Geosynthetics are of ever-growing importance in the construction industry. Sealing of waste storage facilities to safely prevent the emission of wastewater, landfill gas and contaminated dust as well as the diffusion of pollutants into the environment and coastal protection against storms and floods and reconstruction after natural disaster are important fields of application. We will give an overview of the various geosynthetic products. Two examples of the material problems related to geosynthetics are discussed in detail: the effect of creep on the long-term performance of geocomposite drains and the numerical simulation of the interaction of soil with geogrids. Both issues are of importance for the use of these products in landfill capping systems. The various functions, which geosynthetics may fulfill in the protection of coastal lines, are illustrated by case studies. The geosynthetic market is evaluated and economical and environmental benefits, as well as environmental side effects related to the use of geosynthetics, are discussed.