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This paper provides insight into the causes of post-peak strength loss for textured geomembrane (GMX) and nonwoven geotextile (NGT) interfaces. The NGT can be part of a geosynthetic drainage composite (GDC) or a stand-alone NGT. The study used ring shear tests where one of the two interface materials was replaced after reaching a residual strength condition and the test was restarted to measure the change in interface strength. The interface strength loss from peak to large displacement (LD) strength primarily comes from three mechanisms: (1) geomembrane wear, (2) breakage and combing of fibers in the NGT, and (3) reduction of the hook and loop effect between GMX asperities and fibers of the NGT. The source of interface strength loss from LD strength to the residual value mainly comes from breakage and continuous combing of NGT fibers parallel to the direction of shear in ring shear tests. Scanning electron microscopy photographs of the GMX and NGT before and after shearing confirm wear and smoothing of GMX asperities and the combing of NGT fibers in the direction of shear. [ABSTRACT FROM AUTHOR]

This study investigated the performance of unreinforced and geogrid-encased cement-stabilized dredged slurry columns by uniaxial compression tests to simulate the extreme case where the surrounding soil offers no confinement. The objective was to understand the strength characteristics and visualize the deformation damage patterns of the columns with respect to the water content, cement content, length-to-diameter ratio, and geogrid strength. The results show that the unreinforced specimens exhibited strain-softening behavior, whereas geogrid encasement induced strain-hardening, with high-strength geogrids showing superior strain-hardening capacity. Notably, regardless of geogrid strength, encasement enhanced the resistance to deformation and ductility of the columns. Increasing the cement content, reducing the water content, and decreasing the length-to-diameter ratio all contributed to higher peak strength in both unreinforced and geogrid-encased specimens. Geogrid encasement provides confinement that enhances peak strength. The influence of geogrid encasement on peak strength becomes more pronounced at lower cement contents, higher water contents, and higher length-to-diameter ratios. Geogrid encasement also affects failure modes, altering the predominant inclined shear failure observed at the top of unreinforced specimens. Specimens encased with geogrids of higher tensile strength exhibit enhanced integrity and deformation resembling compression strut buckling, with a symmetrically inclined failure trend at the top and bottom. [ABSTRACT FROM AUTHOR]

Lateral restraint is the primary stabilization mechanism associated with the interlocking of aggregate particles in the geogrid apertures. This paper presents findings from a laboratory study which quantifies the local stiffness enhancement of aggregates through micromechanical interlocking provided by two different types of geogrids. These findings are applied to model the resilient response characteristics of geogrid-stabilized base course composite systems. Using three pairs of bender elements as shear wave transducers, horizontal stiffness profiles were determined above mid-heights of aggregate specimens. For two types of geogrids with square- and triangular-shaped apertures, the shear modulus profiles decreased moving away from the geogrid location. Based on a relationship for aggregates, resilient modulus was estimated from the shear modulus. Considering the variations in resilient moduli with distance from the geogrid location, the local stiffness enhancements provided by the two geogrid types were assigned to modulus profiles of a geogrid-stabilized aggregate base course in flexible pavement mechanistic analysis and modeling. The modeling results demonstrate the effect of geogrid base stabilization on the computed pavement resilient responses for both geogrid types. The sublayering approach which properly considers modeling of the geogrid influence zone could be effectively used in mechanistic analysis of a geogrid-stabilized pavement system. [ABSTRACT FROM AUTHOR]

The effect of thermal-oxidative ageing on in-isolation and in-soil stiffness is investigated for two high-density polyethylene (HDPE) and two polyester (PET) geogrids when incubated in an oven at 90°C. It is shown that the in-isolation and in-soil stiffness of three out of the four geogrids decreased during the 4-month ageing time with a faster degradation of the two PET geogrids. In contrast, one of the HDPE geogrids examined with thicker rib showed slower degradation compared to the PET counterparts. It is also shown that a geogrid might have a higher unaged stiffness, but less aged stiffness compared to another geogrid made of the same polymer type. It is suggested that the ageing approach used in this study could be adopted for the selection of geogrids based on their long-term stiffness for structures such as reinforced embankments or mechanically stabilized earth walls that require a long service life. Moreover, results indicate that the stiffness improvement factor for PET geogrids decreases with ageing time. On the contrary, the stiffness improvement factor of the HDPE geogrid increases with time and hypothetically might keep increasing followed by a sudden drop to zero at full degradation of the geogrid. [ABSTRACT FROM AUTHOR]

Geocell reinforcements are proposed as a thrust countermeasure for shallowly buried pipeline bends and tees. The proposed method is easy to construct and has shorter construction time than the use of conventional concrete blocks since it does not require curing. Lateral loading tests were conducted on plates reproducing pipe bends or tees to verify their effectiveness while understanding deformation mechanisms. In addition to changing the plate width and geocell pocket size, additional experiments were conducted with different geocell reinforcement dimensions, geocell tensile stiffnesses and tensile properties of the seams. An equation for predicting the force–displacement relationship was developed as part of the proposed design method. The experimental results showed that the sides of the reinforced ground were not fully integrated when the width of the geocell reinforcement was large relative to the plate width. It was also found that the maximum force hardly decreased, although the displacement increased slightly due to the reduction of the tensile stiffness of the geocells and the tensile force at the geocell seams. Moreover, a hyperbolic approximation of the force–displacement relationship of the geocell reinforcement was developed and the calculated values agreed well with the experimental values. [ABSTRACT FROM AUTHOR]

Most of the world's railways run on ballasted track. However, ballast accumulates differential settlement with trafficking, hence the correct track level must be restored periodically – typically by tamping, which is costly. To reduce the cost of maintenance, several interventions have been proposed with the objective of increasing the interval between tamps by reducing the rate of differential settlement. These include broader ballast gradings, geogrids and under-sleeper pads. A possible alternative is the addition of unbound random fibres to the ballast. Fibres formed from polymer materials, randomly mixed with sands and gravels, have been shown to increase their shear resistance owing to the additional effective confinement associated with the mobilisation of tension in the fibres. However, the effect of the fibres on the permanent strain accumulated under cyclic loading has not been extensively investigated. This paper presents the results of an experimental programme carried out to assess the performance of full-size ballast reinforced with different proportions of polyethylene strip fibres of different lengths and widths. It shows that the addition of a moderate amount (0·6–0·7% of the volume of solids) of narrow fibres has negligible influence on grain packing and can reduce ballast plastic settlement without affecting track resilient stiffness. [ABSTRACT FROM AUTHOR]

Freeze-thaw (F-T) cycles are a major cause of pavement distress in seasonal frost regions, and the presence of fines in bases can accelerate the pavement degradation induced by cyclic freeze and thaw. Among countermeasures used to mitigate the F-T induced damages in pavements, geocell-reinforced bases can be an effective solution in mitigating F-T damage to cold region roads. However, there is almost no research dedicated to understanding the potential benefit of geocells and the underlying mechanisms in this regard. This study employed a custom-made model test device to investigate the F-T performance of geocell-reinforced sands considering different fines contents. The experimental results showed that the increase in fines content substantially increased the peak heave and thaw settlement and decreased the stiffness and ultimate bearing pressure. The application of geocells reduced the peak heave and thaw settlement by 11–18% and 22–35%, respectively, but this benefit was negligible at high kaolin content (12%). The use of geocells increased the stiffness and ultimate bearing pressure by about 43–90% and 41–73%, respectively, after five F-T cycles. The findings of this study are relevant to the design of geocell-reinforced bases under F-T cycles and advance the understanding of the underlying mechanisms. [ABSTRACT FROM AUTHOR]

Interface shear characteristics have an important impact on the stability of geosynthetically reinforced soil structures. The shear characteristics of three-dimensional (3D) geogrid–sand interfaces were investigated using large-scale direct shear tests and the discrete element method (DEM). Geogrids were manufactured by 3D printing. The effect of mesh pattern and transverse-rib thickness on the stress–displacement relationship, strength parameters, coordination number and porosity distribution were evaluated. The results showed that the mesh pattern and transverse-rib thickness have an impact on the interface shear characteristics. The peak and residual interface shear strength of the modified geogrid mesh pattern exceeded that of biaxial geogrids. The average coordination numbers of the modified geogrid mesh pattern were greater than those of biaxial geogrids. The variability of particle compactness, as characterised by the porosity distribution, shows how the modified mesh pattern increases the interface shear strength. The interface shear strength of the geogrid–sand interface was improved by thickening the transverse ribs of the modified geogrid mesh pattern. [ABSTRACT FROM AUTHOR]

Small- and large-scale 1g experiments were conducted to investigate the bearing capacity failure of geosynthetic-reinforced soil walls. The small-scale experiments (1/10) provided fundamental insights into the development of failure based on digital image correlation analysis. Since these tests suffered from scale effects, large-scale tests (1/1.67) were performed to quantify the ultimate load-bearing capacity of a 1.2 m high wall. A vertical load was applied on top of the structures and internal soil movements and stresses, wall deformations and reinforcement strains were measured. The experimental results revealed that the failure was initially triggered at the rear end of the bottom reinforcement. The wall rotated to the backfill and the ground surface in front of the wall was uplifted. The results confirmed the quasi-monolithic behaviour of the reinforced zone. A multi-body failure mechanism was observed below the base of the wall, consisting of an active and a passive wedge connected by a transition zone. Important scaling factors were discussed using the two different scales which has shown important conclusions that are relevant for experimental studies. The analytical calculations revealed that a reduced reinforcement length needs to be considered in the analytical approach to predict a rather conservative load-bearing capacity. [ABSTRACT FROM AUTHOR]

The use of geogrids to anchor Sheet Pile Walls (SPW) is relatively new. A series of small-scale tests was performed to investigate the behaviour of geogrid-anchored SPWs subjected to strip footing surcharge loading. Particle Image Velocimetry (PIV) techniques were used to measure soil displacement and analyse the global failure mechanism and dominant soil-geogrid interaction mechanisms. One of the tests was duplicated in a test box that was eight times as wide, showing that the influence of the small width of the test box was acceptably small. A 2D finite element model (PLAXIS) was used to simulate the tests and there was a reasonable match with the test results. The position of the strip footing load, and the length and number of the geogrid anchors, proved to be key factors in determining the bearing capacity. The results provide new insights into the stabilising effect and the effective length of the geogrid anchors, in other words the length along which geogrid-soil friction is mobilised. Contrary to the Dutch design guidelines for reinforced soil walls and conventionally anchored sheet pile walls, the results showed that the geogrid provides resistance in the active zone under the strip footing surcharge loading. [ABSTRACT FROM AUTHOR]

Different waste materials, such as fly-ash and bottom-ash, slag waste and construction and demolition waste have been extensively studied to replace depleting natural granular materials for fill applications. Waste foundry sand (WFS), a by-product from the aluminium metal-casting industry, is one such waste material that can be a viable fill material. In the current study, extensive large-scale model experimental tests were carried out on geogrid-reinforced WFS beds to understand their load–settlement behaviour. Basic characterisation studies on WFS included gradation, specific gravity, morphology, chemical composition and compaction testing. During large-scale model experimental testing, the geogrid reinforcement was placed at an optimum placement depth, and the maximum improvement in the load-carrying capacity of the footing resting on the reinforced WFS layer was quantified in terms of bearing capacity ratio (BCR). The BCR of reinforced WFS beds was found to be in the range of 1.3–2.0 based on the test conditions considered in the study. The reduction in the settlement of footing on reinforced WFS beds was also quantified. Additionally, the environmental impact of using WFS in reinforced foundation beds was assessed through leachate tests. The dissolved metal concentrations from leachate studies were found to be within permissible limits. [ABSTRACT FROM AUTHOR]

Many researchers suggest using construction and demolition materials (C&D) in engineering applications rather than virgin aggregates (VA). However, the engineering properties of C&D tend to be poorer than those of VA. This study presents the results of plate loading tests performed on unpaved roads with C&D, reinforced by different types of geosynthetics on the soft subgrade. As part of these tests, the effects of some geosynthetic parameters such as (a) the embedment depth, (b) the height and pocket opening of the geocell, (c) the embedment depths and number of geogrids, (d) the distance between geogrids and (e) the stiffness of the geotextile on the bearing capacity of the unpaved road were investigated. Moreover, the same plate loading test was also conducted on an unpaved road built with VA. As a result of this study, although the performance of C&D was determined to be lower than that of VA, it was concluded that C&D performed well enough to be used as an alternative to VA on unpaved roads. Furthermore, with a very small number of geosynthetics, it was determined that C&D could have a better performance than VA. [ABSTRACT FROM AUTHOR]

Five spring-based trapdoor tests allowing continuous displacement during both fill placement and localised static loading were conducted. Quartz sand was used as the test fill. Biaxial geogrids with and without ribs, having two different reinforcement stiffnesses, were used as reinforcement materials. Test results show that when two low-stiffness geogrid reinforcement layers were used, higher reinforcement spacing ratios (defined as the ratio of the reinforcement spacing between two reinforcement layers to the trapdoor width) induced more stable and efficient load transfer generally. Consequently, an optimum value of 0.3 and a worst-case value of 0.1 for the reinforcement spacing ratio were obtained and considered as representatives of two low-stiffness reinforcement layers for comparison with a single high-stiffness reinforcement layer, where their total reinforcement stiffnesses were approximately same. Generally, the inclusion of two low-stiffness reinforcement layers induced more stable load transfer. More importantly, compared with a single high-stiffness reinforcement layer, two low-stiffness reinforcement layers with the optimum reinforcement spacing ratio enhanced load transfer and induced less overall tensile forces, whereas the reinforcement arrangement with the worst reinforcement spacing ratio induced similar load transfer efficiency and overall tensile forces. [ABSTRACT FROM AUTHOR]

In this study, the tensile strength, failure mechanism and ductile behaviour of geogrid-reinforced high-strength self-compacting concrete discs subjected to both the Brazilian tensile strength test and a biaxial compressive test are studied. To determine the combined effects of geogrid layer numbers and inclination angle on the ultimate tensile strength of concrete samples, 21 experiments were conducted with up to three layers of geogrids inclined at angles of 0° to 90°, at increments of 15°. In addition, discrete-element numerical simulations were conducted using two-dimensional particle flow code to examine the failure behaviour of geogrid-reinforced high-strength self-compacting concrete discs. The numerical models were first calibrated by the experimental results and then the failure behaviour of models containing geogrids was investigated. Both experimental and numerical results demonstrate that augmenting the concrete discs with geogrids increases the ductility of specimens, especially after failure. As the number of geogrid layers increased, the tensile strength of specimens also increased, whereas the tensile strength and absorbed energy were the same for specimens with different numbers of geogrid layers and inclination angles of 75° and 90°. The specimen with three horizontal geogrid layers had the highest tensile strength, biaxial compression strength and ductility of all specimens tested. [ABSTRACT FROM AUTHOR]

The reuse of waste materials can help alleviate problems related to placing them in landfill and can also preserve fast dwindling natural granular materials. Waste foundry sand (WFS) can be a promising candidate as a backfill material in the construction of mechanically stabilised earth (MSE) walls. In the design of such MSE structures, the interaction properties between WFS and geogrid reinforcement are important input parameters. In the present study, the interaction properties of a wide range of different polyester (PET) uniaxial geogrids with WFS in two common modes – direct shear and pullout – were evaluated using large-size interface direct shear and pullout tests. In the pullout mode, the interaction of the geogrid embedded in WFS under axial and transverse pullout was studied. The direct shear interface coefficients of four PET geogrids with WFS were found to be in the range observed in conventional fill materials. Higher axial and transverse pullout resistance factors were observed for geogrids with higher tensile strength and higher opening area ratio. Empirical equations were proposed to estimate the axial and transverse pullout resistances of geogrids at two pullout displacements. Finally, sensitivity analyses were carried out to identify the parameters significantly influencing the axial and transverse pullout resistances of geogrids in WFS. [ABSTRACT FROM AUTHOR]

This paper addresses unpaved and paved roads improved with geosynthetics, such as geotextiles, geogrids and geocells. The paper examines the mechanisms associated with the use of geosynthetics to improve roads, describes the principles of the design methods used to quantify the benefits of geosynthetics used in unpaved and paved roads, presents case histories to demonstrate the use of geosynthetics to solve challenging road problems, and discusses the relevance of tests and trials to real roads. This paper is supplemented by four presentations in pdf format that contain more than 800 slides. These four presentations are updated versions of the four presentations made during a one-day short course at the 11th International Conference on Geosynthetics held in Seoul, Korea, in September 2018. The paper that follows contains a summary of each of the four presentations, with special emphasis on key issues. [ABSTRACT FROM AUTHOR]

Analytical solutions for geosynthetic reinforced fills over a void have appeared in the literature starting in the 1980s. Current solutions pay little or no attention to the influence of the creep-reduced stiffness of the geosynthetic reinforcement under tensile loading. This paper addresses this gap by introducing a reinforcement stiffness limit state in the design of these systems. The choice of reinforcement stiffness is based on a simple two-parameter hyperbolic isochronous load–strain model developed by the authors and applied to a large database of uniaxial and biaxial geogrids and woven geotextiles. The paper provides a design chart procedure that can be used with four well-known analytical solutions to compute the maximum reinforcement load. In addition to the stiffness limit state, the design chart approach includes vertical deformation and reinforcement strain serviceability limit states, and a tensile strength limit state. A novel feature of the design charts is a quantitative link to the ultimate strength of the reinforcement to estimate the isochronous stiffness of the reinforcement for different elapsed loading times and strains. There are many instances in the literature where the reinforcement stiffness was taken from a constant rate-of-strain tensile test. The paper shows that this is non-conservative for design. [ABSTRACT FROM AUTHOR]

This paper reports on the performance analysis of an embankment over a soft soil deposit during construction. The study section is part of the duplication of the Brazilian federal highway, BR 470, a major infrastructure project that crosses several soft clay deposits in the state of Santa Catarina, Brazil. To guarantee stability and accelerate the landfill consolidation, the project provided geotechnical solutions as follows: basal reinforcement with geogrids, equilibrium berms, stage constructions of the landfill (slow construction), preloading and prefabricated vertical drains. The performance during field construction was mostly evaluated through instrumentation considering the evolution of horizontal displacements (distortion and distortion rates) and the Asaoka method to evaluate the stabilisation of settlements. Given the limitations of the methods used for control during construction, and a discrepancy between field settlements and original project predictions, the soil profile and geotechnical parameters were revaluated during construction and used in a revised performance analysis. Some important considerations were observed from this back-analysis that could have been used to modify the construction process during execution. In addition, to analyse the effects of the inherited variability, a sensitivity analysis to determine levels of possible settlements and time of consolidation was performed. [ABSTRACT FROM AUTHOR]

This paper presents heave and pullout studies of plain granular pile-anchors (GPAs) and geogrid-encased GPAs. Experiments were conducted in California bearing ratio (CBR) moulds and fabricated moulds of size 381 × 381 × 457 mm in expansive clays. The GPA method is an innovative technique developed for reducing heave and improving bearing capacity and pullout capacity. In this study, GPAs were encased in geogrids to augment the engineering performance of the system. Tests were conducted in CBR moulds and fabricated larger moulds to study and compare the heave and pullout behaviour of plain GPAs and geogrid-encased GPAs. The results indicated that the clay beds reinforced with geogrid-encased GPAs showed better heave and pullout behaviour. Heave decreased by 90.8% and 92.5%, respectively, in the case of plain and geogrid-encased GPAs installed in the CBR moulds and by 95.12% and 98.3% in the case of plain and geogrid-encased GPAs installed in fabricated large moulds. Pullout load on geogrid-encased GPAs in CBR moulds improved by 42.17% over that on plain GPAs and pullout load on geogrid-encased GPAs in the fabricated large moulds improved by 52.25% over that on plain GPAs. [ABSTRACT FROM AUTHOR]

A research study involving full-scale unpaved road test sections was carried out to investigate the performance of unpaved roads reinforced with geogrids. Ten test sections were constructed with two different base course thicknesses. Three biaxial geogrids of different tensile stiffness and one geogrid with triangular aperture were evaluated. Geogrids were placed at the subgrade–base course interface. The sections were instrumented for measuring road response to traffic loading. Traffic loading was provided by a single-axle dump truck. Field measurements of rut depth and surface deformation were recorded at selected traffic intervals. An analysis of the measured performance data indicated that the geogrids effectively reduced surface rutting and improved the performance of unpaved thin base layers and the benefit became more pronounced when a stiffer geogrid was used. The results suggested reductions in the thickness of the base layer by using geogrids of up to 18%. The improvement by geogrids was shown to be less for increasing base layer thickness. In addition, the ability of the design procedure by Giroud and Han to predict rutting performance using the test section parameters as design inputs was assessed. The results indicated that the method underpredicted the required base thickness to support the applied traffic loads. [ABSTRACT FROM AUTHOR]

Pullout behaviour of geogrids is critical to understand for the design of mechanically stabilized earth walls. The pullout coefficients are determined through laboratory testing on geogrids embedded in structural fill. Random forest (RF) is a data-driven ensemble learning method that uses decision trees for classification and regression tasks. In the present study, the use of the RF regression technique for estimation of pullout coefficient of geogrid embedded in different structural fills and at variable normal stress based on 198 test results has been investigated using five-fold cross-validation. 80% of the data has been trained on the model algorithm and the accuracy of the model is then tested on 20% of the remaining dataset. The performance of the model has been checked using statistical indices, namely R2, mean square error, as well as external validation methods. The validity of the model has also been checked against laboratory tests conducted on geogrid embedded in four different fills. The results of the RF model have been compared to results obtained with three other regression models, namely, Multivariate Adaptive Regression Splines, Multilayer Perceptron, and Decision Tree Regressor. The results demonstrate the superiority of the RF-based regression model in predicting pullout coefficient values of geogrid. [ABSTRACT FROM AUTHOR]

Reducing differential settlement between bridges and their embankments caused by an earthquake is necessary to maintain traffic, especially emergency vehicles accessing affected areas. The confined-reinforced earth (CRE) method has been proposed to strengthen the subgrade layer at the bottom of a road pavement and to ultimately reduce road surface unevenness. The method uses granular soil, geogrid layers and confining tie rods. This study presents model experiments designed to investigate the effects of embedded geogrid lengths on CRE behavior under differential settlement and cyclic (vehicle) loads. The CRE was constructed on a fixed plate to simulate a bridge abutment, and on a movable plate to simulate the settlement of an embankment. The results showed that the surface settlement distribution and the maximum surface slope of the CRE decreased with an increase in embedded geogrid length until the geogrids are sufficiently long. Beyond this length value, the deformation only changed slightly. The tensile strain in the geogrids also increased with increased embedded geogrid length under settlement, and the maximum tensile strain increased linearly with increasing settlement. The increment of tensile strain due to the cyclic load was larger for lower geogrid layers than for upper geogrid layers. [ABSTRACT FROM AUTHOR]

The article presents an experimental study of a geosynthetic-reinforced soil (GRS) bridge abutment (BA). The BAs are seated on a saturated soft foundation layer and support a 16 m long concrete bridge. Laboratory tests were conducted on the foundation soil, geogrid, and fill material. The BA is constructed from 14 geogrids and has a total height of 4.2 m. The strain values in the geogrids were measured and recorded during the construction of the abutments and after installation of the bridge structure. The test results show that more than 50% of the total strain in the geogrids was developed during the construction of the BAs, mostly embedded in the ground. The remainder of the measured strain was a consequence of installing the prefabricated bridge girders, back fill placement, concreting the top slab, and placing the asphalt concrete. The strain distribution along the geogrids shows that the maximum strain was recorded below the sill, and was 50% higher than at the center of the BA. Based on an analysis of the construction costs, it can be concluded that conventional reinforced concrete abutments could cost up to five times the amount of optimally designed GRS-BAs. [ABSTRACT FROM AUTHOR]

In this study, a large-scale laboratory test was developed to analyze the contribution of geogrid reinforcement to the improvement of unpaved roads. A detailed experimental protocol was established regarding the road base soil preparation, installation, and soil compaction procedure. Eight tests were performed under a circular plate load test in a box 1800 mm in width, 1900 mm in length, and 1100 mm in height. Under this configuration, three repeat tests were performed to verify the developed protocol. Furthermore, the plate load tests were used to compare different road base thicknesses and geogrid types. Once the developed protocol was confirmed, three tests, using the developed simulator accelerator of traffic (SAT), were performed. Indeed, the same road base configuration was tested, but this time it was placed in a box 5000 mm in length. The prepared road base was subjected to two different loadings: a specific plate load and a traffic load. The results showed the efficiency of the geogrids, the influence of the road base thickness, and the role of the loading type. Moreover, it demonstrated different mobilized mechanisms of the geogrid, depending on the type of product. [ABSTRACT FROM AUTHOR]

Soil erosion can cause serious damage to the environment and significant economic losses since uncontrolled erosion processes have detrimental consequences for agriculture and may cause damage to existing civil infrastructure. Geosynthetic products to protect soils against erosion are available, such as geomats, geoblankets and geocells. This paper investigates the performance of geomats and geoblankets for the protection of slopes against erosion caused by intense rainfall by means of laboratory tests using a rainfall simulator. The influence of the presence of vegetation on the slope was also investigated. Two geomats and three geoblankets were tested. The results obtained showed that these products can provide efficient soil protection, but due attention must be paid to some factors such as the product's physical and hydraulic characteristics, good contact with the soil surface, soil cover ratio and endurance under high rainfall intensities. The results also showed that the presence of vegetation is beneficial against soil erosion, but the level of performance improvement brought by the vegetation will depend on geomat and geoblanket characteristics and properties. [ABSTRACT FROM AUTHOR]

Geocells are three-dimensional cellular expandable mats used to improve the load-carrying capacity of weak subgrades. The expanded geocell pockets take the shape of a honeycomb connected to their neighbouring pockets. This manuscript deals with the importance of considering the exact shape of the geocell pockets in three-dimensional numerical modelling. The data for the calibration of the numerical models was obtained through laboratory plate load tests. The numerical simulations were carried out using finite difference software, Fast Lagrangian Analysis of Continua in Three Dimensions (FLAC3D). The walls of the geocell were modelled using geogrid elements having only tensile load capacity. The interfaces between the geocell walls and the infill soils were modelled using Mohr-Coulomb yield criterion. Three shapes of geocell pockets, viz. an exact honeycomb shape and simplified shapes (square and diamond), were considered in the numerical simulations. The numerical models with an exact shape of pockets have shown better agreement with experimental data, while the models with approximated shape overestimated the actual load capacity. The paper describes the modelling approach and the reasons for more accurate numerical predictions with the exact shape of geocell pockets compared to simplified pocket shapes. [ABSTRACT FROM AUTHOR]

This paper presents experimental and numerical investigations of dense sand slopes supporting an embedded strip footing, considering both unreinforced and geotextile-reinforced cases. The effect of footing location, defined in terms of embedment depth D and edge distance e, on the bearing capacity of the footing was investigated. The results show that the bearing capacity of the footing increased with an increase in D and e. The inclusion of one layer of geotextile reinforcement in the dense sand slope further increased the bearing capacity. This benefit was expressed in terms of BCRu, which is defined as the ratio of the ultimate bearing capacity for the reinforced case to the ultimate bearing capacity for the unreinforced case. The maximum value of BCRu(≈ 2·5 − 3) was observed for D/B = 0 and e/B = 0 where B is the width of the footing, while the minimum value of BCRu(≈ 1·5) was obtained for D/B = 1 and e/B = 3. [ABSTRACT FROM AUTHOR]

The wraparound reinforcement technique has been studied recently by researchers as a way of improving the bearing capacity and load−settlement characteristics of a sand bed supporting a strip footing with a constant land width for foundation, but with the use of varying width of geotextile reinforcement. This research study presents an experimental evaluation of geotextile-reinforced sand bed enhanced with a wraparound reinforcement technique having partially and fully wrapped ends with the use of constant width of the geotextile reinforcement, but with varying land width of the foundation. Laboratory model tests were conducted to investigate the influence of the lap length coverage of wraparound ends on the load−settlement behaviour of reinforced sand. Additionally, an instrumentation programme with pressure cells was designed to study the pressure distribution in foundation sand beneath the geotextile layer. The test results reveal that fully wrapped models possess the most improved behaviour, with about 50% improvement in the bearing capacity and 50% reduction in the land width occupied by the reinforcement compared with a reinforced model without wraparound ends. [ABSTRACT FROM AUTHOR]

Although tire-derived aggregate (TDA) has been used as an alternative backfill in geotechnical engineering applications, the interaction between TDA having large particle sizes (e.g. TDA with a maximum particle dimension of 300 mm) and reinforcing geosynthetics has not been studied. This paper presents results from pullout tests on uniaxial and biaxial geogrids embedded in Type B TDA using a new large-scale pullout device having internal areal dimensions that can accommodate TDA layers with a height up to 1470 mm. Normal stresses ranging from 10 to 60 kPa were applied to TDA layers using dead weights atop a rigid plate and the pullout force was applied via hydraulic actuators operated in displacement control to a bolted-epoxy sandwich-type grip mounted on slide bearings that permit pullout displacements of up to 810 mm. The maximum pullout force increased with normal stress, with a displacement at maximum pullout force ranging from 100 to 350 mm. Internal displacements measured using tell-tales indicate gradual mobilization with pullout force, and the TDA layers all contracted during geogrid pullout. Uniaxial and biaxial geogrids with square-shaped apertures showed higher pullout capacity than uniaxial geogrids with rectangular-shaped apertures, but they experienced combined tensile-pullout failure at higher normal stresses. [ABSTRACT FROM AUTHOR]

The objective of this case study is to evaluate the development of soil arching in an embankment being widened. In two test sections, earth pressures at different locations were monitored to reveal the load redistribution mechanism due to soil arching. Tensile forces in uniaxial plastic geogrids were measured to evaluate the performance of geosynthetic reinforcement in the widened embankment. The soil arching effect was quantified in terms of stress concentration ratio, soil arching ratio and geomembrane effect. Several existing methods were selected to compare with the measured results. The results of the field tests indicate that a two-dimensional plane soil arch with some eccentricity affects the fill load distribution on pile caps and subsoil between piles, and a realistic critical arch height of less than 2.0 m with a ratio of 1.4 times the pile clear spacing was identified. Although few existing methods could generate close results comparable to the measured values, most of the methods overestimated the load carried by the geosynthetic layer. The results also suggest that the foundation soil reaction underneath the geosynthetic layer should be taken into account in the load transfer mechanism of geosynthetic-reinforced and pile-supported widened highway embankments. [ABSTRACT FROM AUTHOR]

This paper deals with geogrid-reinforced artificial barriers used as mitigation works against debris avalanches. Deformable Geosynthetic-Reinforced Barriers (DGRB) can be made of coarse-grained materials reinforced by high tenacity polyester (PET) geogrids, wrapped around the facing and arranged in layers. The peak dynamic impact pressure is here calculated as the sum of a landslide velocity-related component and a static component dependent on landslide height. Dynamic analyses are carried out through the commercial Finite Differences Method code (FLAC, Itasca) capable of adequately reproducing small and large displacements of the impacted barrier. The soil is modeled as elastic perfectly-plastic non-associative granular soil, the geogrids are simulated as traction-resistant, and the iron mesh framework is modeled as beam elements resistant to both traction and bending. Frictional interfaces are considered at soil-geosynthetic contacts. The displacements of specific control points and the global behaviour of the barriers are computed versus time. Tensile stresses in the geosynthetics are evaluated for different combinations of materials. Out of three geometries of the barrier, the more massive with the steeper impact front is outlined as the best choice. More deformable geosynthetics appear to be more effective in dissipating the impact energy inside the barrier. [ABSTRACT FROM AUTHOR]

Using recycled construction and demolition waste (RCDW) in geosynthetic reinforced soil (GRS) structures presents attractive environmental and economic aspects. However, bearing in mind installation damage can be responsible for significant changes in geosynthetic tensile-strain behavior, the damage caused by the RCDW must be assessed and quantified. This study aims to investigate the occurrence of mechanical damage during the installation of geogrids with RCDW backfill material using an in-field test facility. In order to understand the mechanisms related to the damage, the influences of the dropping height and compaction method were investigated. Statistical analysis using the Student's t-distribution was carried out to validate the occurrence of damage and calculate reduction factors for geogrids' tensile strengths. Results revealed that dropping processes reduced the geogrid ultimate tensile strengths, but the compaction methods caused the highest reductions. The reduction factor values encourage the design of GRS structures with RCDW, an interesting option to satisfy the technical and economic aspects required for these structures in agreement with the environmental concerns. [ABSTRACT FROM AUTHOR]

A series of large-scale direct shear tests was conducted to capture the interface shear behaviour of ballast with and without geogrids. A fresh granite ballast with a maximum particle size (Dmax) and average particle size (D50) of 65 and 42 mm, respectively, and five geogrids having different aperture shapes and sizes were used in this study. Laboratory experiments were performed at different applied normal stresses (σn) and rates of shearing (Sr) ranging from 35 to 140 kPa and 2·5 to 10·0 mm/min, respectively. The test results confirmed that the shear strength of the ballast was highly influenced by σn and Sr. The internal friction angle of the ballast (ϕ) was found to decrease from 66·5 to 58° and the dilation angle (ψ) from 25·24 to 8·05° with an increase of σn and Sr. Moreover, sieve analysis of ballast samples after testing revealed that a significant amount of particle breakage occurred during shearing. The breakage of the ballast, evaluated in terms of Marsal's breakage index (Bg), increased from 5·12 to 13·24% with an increase in σn and Sr. However, the inclusion of geogrids was found to have a profound influence on the interface shear strength and reducing the extent of the dilation angle and particle breakage. [ABSTRACT FROM AUTHOR]

Stability of geosynthetics along slopes in covers and liners of landfills depends partly on their tensile strength and partly on the efficiency of anchors holding the geosynthetics at berms or the top of the slope. The pull induced in these geosynthetics is in an inclined direction parallel to the slope. But due to difficulty in modelling inclined pullout behaviour experimentally, very few studies have so far been conducted on geosynthetics embedded in anchor trenches. This paper presents details of a device that can perform inclined pullout tests on geosynthetics at variable inclinations. Since geogrids are widely used as veneer reinforcement, inclined pullout tests are conducted on geogrids embedded in run-out, I-type and L-type anchors in sand. The maximum pullout force in the geogrid increases by more than 20% as the pull inclination increases from 0° to 20° in all the three types of anchors. The geogrids exhibit markedly different force-displacement behaviour for the three types of anchors, though the length of reinforcement remains the same. The peak pullout force for the I-type anchor was 1.6–1.7 times higher, and that for the L-type anchor was 2 times higher than that of the run-out anchor at all pullout inclinations. [ABSTRACT FROM AUTHOR]

Mechanical and hydraulic properties of recycled concrete aggregate (RCA) were evaluated for use as backfill in mechanically stabilized earth (MSE) walls. Large-scale drained triaxial tests, direct shear tests and pullout tests were performed to obtain mechanical properties of RCA interacting with various geosynthetics. Long-term filtration (LTF) tests were performed to evaluate hydraulic conductivity of RCA-geotextile systems. Results showed that the RCA had an internal friction angle of 49°, which was within the typical range. The RCA-uniaxial geogrid had the highest interface friction angle of 36° – and the interface friction angles of RCA-biaxial geogrid, RCA-nonwoven geotextile, and RCA-woven geotextile were 32°, 26° and 22°, respectively. Reinforced RCA showed comparable pullout capacity to reinforced sand. No slippage was observed between the RCA and geotextiles or geogrids, and the failures occurred mainly due to rupture of the geotextiles and geogrids during the pullout test. Results of the LTF tests showed that, over a filtration period of 2500 h, the ratio of mean hydraulic conductivity of RCA only to that of RCA-nonwoven geotextile and RCA-woven geotextile systems remained between 0.91 and 3.2, suggesting that the clogging of the geotextiles with RCA was minimal. [ABSTRACT FROM AUTHOR]

Use of geosynthetic reinforcement may improve the performance of many geotechnical systems, including anchors. In this study, the uplift capacity of geocell-reinforced sand is studied based on a series of near large-scale experiments and calibrated three-dimensional Finite Element (FE) models. Using the verified FE models, a comprehensive parametric study of over 270 models was performed to assess the influence of friction angle, geocell stiffness, embedment depth, anchor size, and geocell-anchor width ratios on uplift capacity. Uplift capacity increases with embedment depth and friction angle, but the relative increase is more pronounced for loose sand. The observed shape effects are amplified in reinforced installation. The increase in uplift capacity observed decays for geocell-anchor width ratios greater than 3, but an increase in geocell stiffness demonstrates increased uplift capacity through the increased mobilization of geocell resisting uplift. Finally, based on the verified numerical models, a semi-empirical equation is proposed to enable estimation of uplift capacity in geocell-reinforced sand, demonstrating good agreement with results from numerical simulations. [ABSTRACT FROM AUTHOR]

Geogrids have been found to improve the performance of unbound aggregate layers in transportation applications by providing confinement and arresting movement through interlock between individual aggregate particles and their apertures. Geogrid reinforcement offers an effective remedial measure when railway structures are susceptible to track geometry defects resulting from excessive movement and particle reorientation within the ballast layer. This paper presents an ongoing research study at the University of Illinois aimed at quantifying the effects of geogrid reinforcement on the shear strength and permanent deformation behaviour of geogrid-stabilised railroad ballast. Geogrids with triangular, rectangular and square apertures were tested in the laboratory experiments. Cylindrical ballast specimens were prepared and tested with geogrids placed at different heights within the specimen using a large-scale triaxial apparatus. An imaging-based discrete-element-method approach was developed to model triaxial test results and investigate geogrid-reinforcement mechanisms. With the capability to create actual ballast aggregate particles as three-dimensional polyhedron elements having the same particle-size distributions and imaging quantified average shapes and angularities, the modelling was able to capture the ballast behaviour with and without geogrid reinforcement reasonably accurately. [ABSTRACT FROM AUTHOR]

Full-scale test sections were constructed and trafficked at the U.S. Army Engineer Research and Development Center (ERDC) to provide performance data for comparing the effectiveness of multi-axial geogrid stabilised flexible pavement sections with an unstabilised flexible pavement section. Two test sections containing differing multi-axial geogrids were constructed and trafficked under shelter in ERDC's hangar 2 pavement test facility. The test sections were subjected to accelerated traffic loading using a dual-wheel tandem-axle configuration simulating typical highway loadings. Permanent surface deformation, rutting, pavement stiffness and instrumentation response data were collected at designated traffic intervals. The results of the study indicate that the geogrid stabilised sections improved the performance of the pavement section when compared with the unstabilised section. [ABSTRACT FROM AUTHOR]

In this study, laboratory-scale experiments are carried out to investigate the interference effect on bearing capacity and settlement behaviour of two closely spaced identical footings placed on the surface of a sand layer of limited thickness underlain by a soft clay layer with geogrid at the interface. Three pairs of model footings of different sizes are used in the study. The width (B) and length (L) of the footings are chosen in such a way that the L/B ratio (aspect ratio) of the footings is varied as 1.0 (square), 1.5 (rectangular) and 2.0 (rectangular). It has been observed that there is an optimum spacing where the bearing capacity of the interfering footing reaches the maximum value. The optimum spacing is found to be 2.0 times the width of the footing for all shapes of footings at H/B = 0.75, where H is the thickness of sand over soft clay. The maximum interference factor for bearing capacity (for a square footing) in homogeneous reinforced sand is 18% more than the sand-clay layered soil. The influence of footing interference increases with an increase in L/B ratio. The strain distribution along the reinforcement is also investigated and it is found that the strains in the reinforcement vary with the spacing ratio. [ABSTRACT FROM AUTHOR]

This report presents a new large-scale test apparatus (LSTA) developed to assess the efficiency of a geosynthetic reinforcement for the limitation of deformations of a geosynthetic lining system (GLS) over a 0.5 m wide cavity. Two experiments were conducted. The first one involved a geosynthetic clay liner, a nonwoven needle-punched geotextile and a high-density polyethylene geomembrane. For the second experiment, a 50 kN/m polyvinyl alcohol geogrid was imbedded within the sand layer below the geosynthetic clay liner to provide reinforcement above the cavity. An overburden pressure varying from 10 to 100 kPa was applied to the top of the GLS. Strain gauges were used to measure the strain within the geogrid and the geomembrane. The results proved that the 50 kN/m geogrid reinforcement beneath the geomembrane reduced the maximum strain within the geomembrane, compared to the case where the geomembrane was unreinforced, by 25% on average. The results showed that the overall strain within the geomembrane was 31% to 42% less than that of the geogrid above the cavity. Finally, the results showed that the spatial distribution of the strain within the geomembrane and that of the geogrid differed because of a conical shape of the collapsed zone. [ABSTRACT FROM AUTHOR]

This paper presents the results of numerical simulations of one physical full-scale unreinforced embankment and two reinforced embankments taken to failure using a strip footing. The embankments were 3.4 m in height and were constructed with the same slope using the same sand backfill. One reinforced embankment was constructed with a relatively weak and extensible geogrid material and the other with a relatively stronger and stiffer geogrid product. Deterministic finite element method (FEM) and random finite element method (RFEM) analyses were carried out and the results compared to observed performance. Analyses were performed assuming vertical spatial variability in soil strength at a scale of fluctuation matching the compaction lift thickness of the physical tests and treating the soil as a random (homogeneous) material. Both deterministic and probabilistic analyses showed good agreement with the measured bearing capacity of the footing in each full-scale test. However, the assumption of vertically anisotropic spatial variability in soil strength was shown to achieve a better match with the observed failure mechanism in each of the embankments. [ABSTRACT FROM AUTHOR]

This paper presents a full-scale test of high-speed railway embankments over completely decomposed granite soil foundations in order to investigate the performance of geosynthetic-reinforced and pile-supported (GRPS) embankments. The emphasis is placed on the study of the load-transfer mechanisms in those GRPS embankments and on verifying the existing design approaches, taking into account soil arching effects. To do so, four fully instrumented embankment sections were studied, with two sections of geogrid-reinforced and cement-mixing pile-supported embankments and the other two of geogrid reinforcement only. Six commonly used existing design methods for GRPS embankments were tested to show their limitations and applicability. Experimental data from field monitoring for nearly 2 years in these sections were obtained. Results show that all of the six existing design methods tested significantly over-predict the pile efficiency at the end of full embankment, thus leading to a conservative design. BS 8006 and modified BS 8006 yield an overestimation of geogrid strains and thus a conservative estimation. However, all the other methods tested for geogrid strain calculation may lead to an unsafe design. Therefore, it is highly recommended to compare the design results using different approaches in order to optimise the design. [ABSTRACT FROM AUTHOR]

A series of experiments on the unreinforced sand bed (USB) and geogrid-reinforced sand bed (GRSB) placed over a group of floating stone columns in soft clay and their numerical simulations have been conducted. Three-dimensional numerical simulations were performed using the finite-element package ABAQUS 6.12 for modeling the USB and GRSB placed over a group of stone columns floating in soft clay. In finite-element analysis, geogrid is modeled as an elasto-plastic material. Compared to unreinforced clay, 1.72-fold, 2.83-fold and 5.30-fold increases in bearing capacity can be achieved by the provision of only stone columns, stone columns with USB and GRSB, respectively. The critical thickness of USB and GRSB can be taken as equal to 0.3 times and 0.2 times the diameter of the footing; above this thickness, improvement in the bearing capacity is marginal. Both the improvement factor and stress concentration ratio of the stone columns with GRSB show an increasing trend with an increase in settlement. The optimum length of the group of floating stone columns with GRSB is six times the diameter of the column. Plastic strain developed in the stone column material is much higher than that in the geogrid planar sheet. [ABSTRACT FROM AUTHOR]

Geocell-reinforced retaining walls are widely used in engineering practice due to their advantages of light weight, simple construction, low environmental impact and aesthetics. However, limited studies can be found on the failure mechanisms and method of stability analysis for this type of earth structure. In this study, limit equilibrium analysis to predict the global stability of geocell-reinforced retaining walls is conducted. The results indicate that the classical Rankine and Coulomb theories of earth pressure are not suitable for analyzing the stability of geocell-reinforced retaining walls. Instead, the failure mechanisms of geocell-reinforced retaining walls are similar to those of slopes. The general limit equilibrium method, with an assumption of a polygonal failure surface and assisted by the improved Monte Carlo searching technique, may reproduce the critical failure surface. The analyzed factor of safety along the critical failure surface may be somewhat higher than the actual one; this difference is related to the soil density and progressive failure of soil along the critical failure surface. The effectiveness of the analytical approach is validated by two sets of model tests. It is shown that the stability of geocell-reinforced retaining walls may be analyzed by the general limit equilibrium method, provided that the apparent cohesion of geocell-reinforced soil is accurately estimated and the shape of the critical failure surface is properly assumed. [ABSTRACT FROM AUTHOR]

Model plate load tests of rigid rectangular footings of different aspect ratios resting on sand overlying soft soil with or without a layer of geogrid at the interface are presented. The width ( B) and length ( L) of the footings are chosen so that the L/ B ratio (aspect ratio) is varied as 1.0, 1.5, and 2.0. The study aims to investigate the effects of the aspect ratio of the rectangular footings and the thickness of the sand layer on bearing capacity, settlement characteristics, load-spread angle, and sizes of geogrid layer (at optimum sand thickness). The strain distribution along the reinforcement is also studied. Based on the test results, an analytical method is proposed to calculate the load carrying capacity of rectangular footings resting on reinforced or unreinforced sand over soft soil. It is found that the optimum sand thickness to footing width ratio is not dependent on the aspect ratio of the rectangular footings. However, the optimum sizes of geogrid reinforcement increase with an increase in aspect ratio of the footings. Also, the load-spread angle increases with an increase in aspect ratio. It is also observed that the load-spread angle in the lengthways direction of a footing is smaller than that in the widthways direction, and it is more pronounced in the case of reinforced soil compared to unreinforced soil. [ABSTRACT FROM AUTHOR]

Residual deformations due to sustained and cyclic loading, acting on full-scale reinforced soil-retaining walls, could lead to an unacceptable serviceability limit state. In the present study, the writers carried out an extensive experimental programme comprising several monotonic and multistage tensile tests on a high-density polyethylene (HDPE) uniaxial extruded geogrid. Based on analysis of the test results, a combined empirical model has been developed that can predict the tensile behaviour of a specific HDPE geogrid subject to cyclic tensile loading. The paper presents the results and analyses of the effect of cyclic tensile loading histories (varying pre-stress tensile load, frequency, amplitude and number of cycles) on those parameters that are characteristic of hysteresis loops (i.e. the maximum and residual strains cumulated during each cyclic loading, tensile stiffness and area of the hysteresis loops). The results show that the average strain rate and the loading time affect the material's tensile response, as well as the combination of pre-stress tensile load and loading amplitude. The writers also investigated the difference between the load-strain relations for the monotonic test and those for the multistage tests, and concluded that the effects of cyclic loading histories are not due to material degradation. [ABSTRACT FROM AUTHOR]

In a previous study, a series of 9 model tests performed on embankment models resting on soft clay treated with and without ordinary stone columns (OSC), encased stone columns (ESC), and with horizontal layer of geogrid at interface and at 0·1 h height has been carried out to investigate the behaviour of piled (stone columned) and geogrid reinforced embankments. In this paper, these tests are simulated numerically by the finite element method using the program Geostudio (SIGMA/W). Firstly, reanalysis was done of experimental work of embankment models constructed on soft clay treated with OSC and ESC. Secondly, embankment models reinforced by a horizontal layer resting on soft clay strengthened with OSC and ESC were analyzed. A horizontal layer of geogrid is embedded at different levels of embankment height. It was concluded that in the embankment models constructed on soft clay treated with stone columns at a spacing s = 2·5 d with length to diameter ratio L/d ratio = 8, the maximum bearing improvement ratio (qt/qunt) equals 1·33 for the ordinary stone columns and 1·59 for the encased stone columns and about 1·13 and 1·23 when one layer of geogrid is embedded at interface or at 0·1 h height, respectively. [ABSTRACT FROM AUTHOR]

A well-designed field experiment was carried out to enhance the understanding of a geogrid-reinforced and floating pile-supported (GRFPS) embankment constructed on alluvial soil with medium-low compressibility (ASMLC). Two test sections with identical reinforcement solutions and fill load were chosen for field monitoring which lasted approximately 32 months. The measurements, including pore water pressure, settlement, soil stress, strain in geogrid, and lateral displacement during and after the embankment filling, were reported and the performance of GRFPS embankment was examined. The results indicate that the downward movement of the floating pile allowed the fill load to transfer from the pile (cap) to the subsoil and mobilised more counter support from the subsoil. Less soil arching effect and tensioned membrane effect were observed, and so were the stress concentration ratio and strain in the geogrid. The floating pile with limited embedment depth is sufficient to control both the total settlement and lateral displacement. The existing design procedures are expected to be overly conservative for GRFPS embankment constructed on alluvial soil with medium-low compressibility, and some recommendations are proposed to help with the design. [ABSTRACT FROM AUTHOR]

Although geogrids and geotextiles have been successfully used for over a quarter of a century to reinforce soil, there are currently no commonly agreed analytical methods to model their deformation behaviour. The serviceability limit state is becoming an ever more important design consideration, as structures are built with increasingly tighter tolerances. Although there are many deformation databases and design charts available, providing information and guidance on the sensitivity to certain design variables, these are largely focused on facets such as height, shear strength and geogrid ultimate strength and do not consider construction method. Following a review of existing analytical and empirical guidance, this paper presents numerical modelling-derived guidance for flexible faced geogrid-reinforced structures constructed using cohesionless fill that incorporates installation methods. The modelling approach is validated against measured results from three varied case studies, before analysing the changes in deformation distribution resulting from two different construction methods (layer-by-layer and full height construction). For the conditions analysed, including height of the structure, the lateral deformation resulting from layer-by-layer construction, was shown to be consistently greater, than for full height construction. In contrast, an analysis of post-construction deformation, for each of the construction methods, found full height construction to be more sensitive to post-construction loading, for the conditions considered. For low wall height structures constructed using the layer-by-layer method, < 5 m, the present study indicates that horizontal face deformations are underestimated by current guidance. [ABSTRACT FROM AUTHOR]