In performance-based design, it is crucial to understand deformation characteristics of geocell layers in soil under footing loads. To explore this, a series of laboratory loading tests were carried out to investigate the influence of varying parameters on the strain levels within the geocell layer in a sandy soil under axial strip footing loading. The results were analyzed in terms of maximum strain levels, strain variation along the geocell layer and the correlation between horizontal and vertical strains. In this study, the maximum observed strain levels for geocellreinforced strip footing systems reached 2.3 % for horizontal (tensile) strain and 1.4 % for vertical (compressive) strain. Furthermore, most strain levels were concentrated within a distance of 1.5 times the footing width from the axis of strip footing. In geocell-reinforced footing systems, the interaction between horizontal and vertical strains becomes a key factor, with the ratio of horizontal to vertical cell wall strains ranging approximately from 1 to 2.5. The outcomes of this study are expected to contribute to the practical applications of geocell-reinforced footing systems.

Buried pipes are subjected to static and dynamic loads depending on their areas of use. To mitigate the risk of damage caused by these effects, various materials and reinforcement methods are utilized. In this study, five buried uPVC pipes designed in accordance with ASTM D2321 standards were reinforced with three different ground improvement materials: Geocell, Geonet, and Geocomposite, and experimentally subjected to dynamic impact loading. Acceleration, velocity, and displacement values were obtained from the experiments. Subsequently, finite element analysis (FEA) was performed using the ABAQUS software to determine stress values and volumetric displacements in the pipes, and the model was validated with a 5-7% error margin. In the final stage of the study, a parametric analysis was conducted by modifying the soil cover height above the pipe and the Geocell thickness in the validated finite element model. The parametric study revealed that the displacement value in the pipe decreased by 78% with an increase in soil cover height, while a 16% reduction was observed with an increase in Geocell thickness. The results demonstrate that the soil improvement techniques examined in this study provide an effective solution for enhancing the impact resistance of buried pipeline systems.

Geocells are three-dimensional, interconnected cellular geosynthetics widely used to enhance the overall strength of soils. Their foldable structure can cause variations in pocket shape during installation, depending on the extent of extension. Understanding the impact of these shape variations is essential for optimizing reinforcement efficiency and reducing the associated geocell application costs. The aspect ratio, defined as the ratio of the cell's transverse (welded) axis to the longitudinal (wall summit) axis, is proposed to evaluate the degree of extension of the most commonly utilized honeycomb-shaped geocell. A coupled continuum-discontinuum numerical method was employed to investigate the behavior of honeycomb-shaped geocell reinforced soils across various aspect ratios under confined compressive loading. The simulation results indicate that a geocell with an aspect ratio of 1.0 exhibits optimal reinforcement efficiency, and whereas reinforcement efficiency decreases as the aspect ratio deviates from 1.0 causing pocket geometries to flatten. The superior performance of rounded geocells is attributed to their enhanced ability to promote load-bearing in strong contact subnetworks. This results in denser packing structures, higher contact force anisotropy from a microscopic perspective, and greater confinement capacity against deformation from a macroscopic perspective.

Freeze-thaw (F-T) cycles are a primary contributor of pavement damages in seasonal frost regions. Geosynthetics stabilization has been a promising solution for enhancing the roadways performance in cold regions. However, in comparison with the practical applications, research on the geosynthetics stabilization in cold-region roads is scarce and its efficacy is yet to be quantified. This study presents the full-scale test on geosynthetics-stabilized sections in a flexible pavement in Sturgeon County, Alberta. It focused on the investigation of three separate test sections with bases stabilized by two types of geocells and one geogrid composite, each fully instrumented with earth pressure cells, thermocouples, and moisture sensors. This experimental program consisted of plate loading tests and trafficking tests on each test before and after the first F-T season, and monitoring of soil temperatures, moisture contents, and loads transferred to subbases while the sections were open to general traffic. The results showed seasonal F-T cycles resulted in increased pavement settlement, decreased load transfer ratio, and increased stress distribution angle under the plate loading. The traffic-induced stress on the subbases increased during the spring thaw but decreased afterwards.

Although Novel Polymeric Alloy (NPA) geocells have been applied to stabilize road bases against the freeze-thaw (F-T) damage in practice, the relevant research lags the application. A scarcity of research has been reported to comprehensively evaluate the benefits of geocell stabilization in enhancing the F-T performance of bases. This study aims to investigate quantitatively the F-T performance of geocell-stabilized bases, focusing on two influencing factors-i.e., water supply and degree of compaction in the bases. A series of model-scale experimental tests (19 tests) was conducted using an upgraded customized apparatus. The results showed that the inclusion of geocells was beneficial for reducing frost heave and thaw settlement as well as mechanical properties (i.e., stiffness and ultimate bearing capacity) of road bases. The benefit of geocells was more remarkable for the well compacted bases than for the poorly compacted bases. The benefit was more pronounced in the open system than in the closed system.

Geocells have become an integral part of many geosystems like road and railway embankments, retaining walls and foundations, attributed to their multiple merits in terms of stability and strength, but their contributions towards liquefaction mitigation are unknown. The present study aims to understand the role of geocell reinforcement on the liquefaction and post-liquefaction shear response of saturated sands through monotonic and cyclic triaxial tests. Low-strength geocells of required physical and mechanical properties were fabricated through ultrasonic welding of 3D printed polypropylene (PP) sheets. The liquefaction benefits of including a single geocell in sand were quantified in terms of the reduction in pore water pressure, retardation in stiffness degradation and delay in the retardation of effective stress. In general, the inclusion of geocells delayed liquefaction, with higher beneficial effects at lower initial confining pressure, higher cyclic strain amplitude and higher cyclic loading frequency. The maximum benefit measured in terms of percentage rise in the number of cycles needed to liquefy was calculated to be about 230 %. Geocell reinforcement also helped in the quick regain of post-liquefaction shear strength and stiffness.

Record-breaking rainfall from February to July 2022 caused widespread damage to multiple road sections within the local government area of Shoalhaven NSW, Australia. With approximately 2059 mm of rainfall in the Kangaroo Valley area alone, which was more than double the rainfall what residents would normally experience, Shoalhaven City Council experienced the wettest year on record. As a direct result of this rainfall, multiple sections along several roads have been severely affected by slope instability resulting in road damage (including 98 landslips affecting 23 roads) restricting local residents from accessing even nearby towns. Accordingly, the local Council sought feasible options that could provide temporary yet safe access to local residents. Among a number of feasible options considered, the proposed use of geocell reinforcement was selected as the preferred short-term remediation option to temporarily restore road use and facilitate safe passage. This paper presents a case study of the performance of a landslide-impacted of Wattamolla Rd, Woodhill, NSW that was stabilised with geocell reinforcement. Limit equilibrium method and finite element analysis were undertaken to design the temporary access through the landslide affected of the road. This study showed that geocell can effectively be used as a temporary solution and has feasibility as a permanent solution, where roads are impacted by landslide. Results showed that by confining infill material, geocell minimised axial deformations and lateral spreading and provided a semi-rigid platform that improved the stability of the road embankment.

Polymer-blend geocell sheets (PBGS) have been developed as substitute materials for manufacturing geocells. Various attempts have been made to test and predict the behaviors of commonly used geogrids, geotextiles, geomembranes, and geocells. However, the elastic-viscoplastic behaviors of novel-developed geocell sheets are still poorly understood. Therefore, this paper investigates the elastic-viscoplastic behaviors of PBGS to gain a comprehensive understanding of their mechanical properties. Furthermore, the tensile load-strain history under various loading conditions is simulated by numerical calculation for widespread utilization. To achieve this goal, monotonic loading tests, short-term creep and stress relaxation tests, and multi-load-path tests (also known as arbitrary loading history tests) are performed using a universal testing machine. The results are simulated using the nonlinear three-component (NLTC) model, which consists of three nonlinear components, i.e. a hypo-elastic component, a nonlinear inviscid component, and a nonlinear viscid component. The experimental and numerical results demonstrate that PBGS exhibit significant elastic-viscoplastic behavior that can be accurately predicted by the NLTC model. Moreover, the tensile strain rates significantly influence the tensile load, with higher strain rates resulting in increased tensile loads and more linear load-strain curves. Also, parametric analysis of the rheological characteristics reveals that the initial tensile strain rates have negligible impact on the results. The rate-sensitivity coefficient of PBGS is approximately 0.163, which falls within the typical range observed in most geosynthetics. (c) 2024 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/ licenses/by-nc-nd/4.0/).

Geocell has a confinement effect, limiting the deformation of soil and enhancing the strength of reinforced soil, and has a wide range of application prospects in traffic transportation subgrade engineering. To investigate the confinement effect of geocell on the mechanical characteristics of reinforced sand subgrade, this paper analyzes the macro-mechanical properties of reinforced sand subgrade using triaxial tests, investigates the micro- reinforcement mechanism employing discrete element method (DEM)-based simulations. The potential macro- -micro linkages are studied. The experimental results revealed that the volumetric strain of the geocellreinforced samples increased with the material's elastic modulus, exhibiting a shear shrinkage phenomenon. The deformation pattern of the reinforced samples presented segmental deformation, which differed from that of the unreinforced sand samples. The geocell enhanced the cohesion intercept of the sand samples while having a minimal impact on friction angle. Through the analysis of numerical simulation results, it was found that the geocell constrained the displacement of the soil particles, altering the shear band development trend of the sample and resulting in segmental deformation. The geocell facilitated the concentration of force chains, enhancing their stability and resulting in improving the strength in the macro. Additionally, it was observed that the confinement effect of the geocell significantly reduced the fabric and force anisotropy of the granular soil, promoting consistent vertical alignment of force chains. This, in turn, enhanced the vertical force transmission capacity of the sample, explaining the micro-mechanism by which the confinement effect of the geocell increases the peak shear strength of the samples.

Most forest roads are unpaved, connecting rural and forest areas and enabling access for firefighting and commercial purposes. Low traffic levels lead to reduced functional demands, while rapid development of deformations results in frequent maintenance. Using geocells as reinforcements reduces deformations, minimizing maintenance needs. Herein, geocell-reinforced soil design methods were collected and categorized based on their result: increase in confining pressure; bearing capacity; height of the base layer. The goal was to compare methods reported in the literature, from a user perspective and within each category, using a base scenario. The methods were analysed to better understand their differences and application conditions. Methods that estimate the increase in confining pressure refer to static or cyclic loading, leading to results that are not directly comparable; often, the reinforcement contribution is represented by an apparent cohesion, with no physical meaning and misleading. Methods that estimate the increase in bearing capacity due to geocell consider its contribution differently (lateral resistance, vertical stress dispersion, and membrane effects) and distinct combinations. For geocell reinforcement, the membrane effect can be neglected. Methods that estimate the height of the base layer can be used directly for an expedite design of unpaved roads. When geocell reinforcement is adopted, the minimum height of the base layer should coincide with that of the geocell. Thus, while current methods contribute and support the design of unpaved roads, further work is essential to develop methods that are of simple and of expedite application for forest engineers, adaptable to local conditions and requirements.