Vertical stiffness and shear strength of ballasts are significantly degraded when contaminated with sands. There is a lack of solutions/studies related to strengthening ballast against sand contamination. Addressing this limitation, a comprehensive laboratory investigation was made on effectiveness of geogrid reinforcement for improvement of mechanical properties of sand-contaminated ballast. To this

The self-healing of a GCL with artificial defects (circular holes and rectangular slits, both with and without the carrier geotextile preserved below the holes) upon hydration on a Godfrey silty sand (GSS) subgrade with wfdn = 5, 10 and 16% under 2–100 kPa is examined. Circular holes with the carrier geotextile missing below holes with diameters up to 25.4 mm self-healed on the wfdn = 5% and 10% GSS

Plate loading tests were conducted to investigate the effect of a bottom boundary condition on the pressure-settlement behavior of a footing on sand with a limited thickness involving geosynthetics. Seven boundary materials including geosynthetics were used to create different boundary conditions at the bottom of the sand. Interface direct shear tests were conducted first to determine the interface

The basic pore unit model is extended to predict the strained pore size characteristics of woven slit-film geotextiles subjected to unequal biaxial tensile strains. The strained per cent open area (POA) and analytical pore size are expressed as functions of the weft strain and the warp strain to weft strain ratio. The influence of the biaxial tensile strain on pore size characteristics is evaluated

Aqueous diffusion of trichloroethylene (TCE) and tetrachloroethylene (PCE) is examined for high density polyethylene (HDPE), linear low density polyethylene (LLDPE), polyurethane/urea, and two polyethylene (PE) geomembranes coextruded with ethylene vinyl alcohol (EVOH). Additionally, the diffusion of benzene, toluene, ethylbenzene, and xylenes through polyurethane/urea geomembrane is examined. Permeation

This study investigates the influence of clogging substances on pore characteristics and permeability of geotextile envelopes that were used for 3, 7 and 15 years in irrigated farmlands in Xinjiang region, which is arid and suffers from the soil salinity problem. Results show that the macropores (above 125 μm) of envelopes are evidently clogged, whereas the smaller pores less than 100 μm are still

Landfills are sequentially filled by solid waste lifts, thus normal stress on the liner interface changes in different shear stages, which may affect selection of interface strength in landfill slope stability analysis. Shear tests were conducted at the liner interfaces of geomembrane/geotextile (GM/GT) and geomembrane/geocomposite/sand (GM/GC/Sand), and the normal stress changed in different shear

Flexible, sand-filled, geotextile bags (geobags) have been used in both India and Bangladesh along the banks of the Brahmaputra for protection against riverbank erosion. Geotextile containers have been researched extensively for their use in coastal structures; however, there is a gap in knowledge of the application of smaller geobags used in riverbank protection structures. In 2018, flume experiments

This study proposes a procedure for predicting the required tensile strength of geosynthetics for three-dimensional (3D) geosynthetic-reinforced soil structures (GRSSs) comprised of cohesive backfills subjected to earthquake loadings. This procedure is undertaken using the kinematic approach of limit analysis together with a pseudo-dynamic approach. The influence of cracks is incorporated into the

This paper proposes a method to predict the lateral earth pressures on nonyielding retaining walls with geofoam inclusions. The previous study of the lateral stress-strain relation of the backfill was extended, and the solution was derived by the iterative method. The proposed solution could be applied without the known value of the compression of the geofoam inclusions. Model tests for nonyielding

This technical paper presents a unique comparison of geomembrane factory and field welded thermal seams for a large off-stream water reservoir project. The results of the comparison show that factory welded seams exhibit higher seam peel and shear strengths at yield, less variability, and more consistency than field welded thermal seams. In particular, the results show that factory seams are about

In this study, an experimental investigation has been conducted on a circular footing model subjected to eccentric load resting on the geonet-reinforced sand. To this end, five series of tests were carried out in order to evaluate the effect of reinforcement dimension and eccentricity on the bearing capacity, settlement, and rotation of the footing. Results show that the bearing capacity ratio (BCR)

This research evaluates the shear strength properties of unreinforced and geogrid-reinforced ladle furnace slag (LFS), electric arc furnace slag (EAFS) and a blend comprising 50% LFS and 50% EAFS (LFS50+EAFS50) using the large direct shear testing apparatus (DST). The large DST results of unreinforced steel slags indicated that LFS had the lowest shear stress ratio at the peak shear strength among

The paper examines the effects of settlement-induced downdrag on geosynthetic liner systems for a waste containment facility with steep side slopes for different design scenarios, and conducts the stability analysis of the waste mass during waste filling operations. Without the presence of a reinforcing layer above a geomembrane (GMB) liner, the liner experiences unacceptable tensile strains under

A simplified equation, which allows for the calculation of the tension force using the actual tube height and pumping pressure with the flexibility to use a coefficient of lateral pressure (K), is proposed and validated theoretically by comparing the proposed method with two well-known methods in the literature, and experimentally, by conducting several half cross-section tests. The half cross-section

This paper proposes using geofoam blocks to improve the safety of buried steel pipelines under permanent ground deformation due to strike-slip fault rupture. Since these geofoam blocks are deformable, they can compress during fault rupture and thus reduce the pressure imposed on the pipeline by the surrounding soil. This means that the pipe can sustain a higher level of tectonic deformations. For the

Rail tracks continue to deform due to degradation of ballast under the application of heavy train traffic. The resulting track deformations often lead to drainage impairment as well as loss of resiliency. For track replenishment, deep screening of ballast is usually adopted by Indian Railway (IR) either after 10 years or passage of 500 MGT traffic, whichever is earlier. To study the effectiveness of

This paper presents a study on stochastic evaluation of leakages through holes in wrinkle networks of composite liners. The statistical parameters of wrinkles are used as indexes to describe the spatial distributions of wrinkles in a wrinkle network and the wrinkle density is modeled as a random field in the proposed approach, which allows the construction of a database about how wrinkles may be distributed

This study proposes an analytical method for the calculation of the safety factor against lateral spreading in embankments, both for cases with and without basal reinforcement. Hence, a new limit equilibrium approach is presented based on the lower bound plasticity theorem, which allows the computation of the required distribution of stresses along presumed slip surfaces at the limit state. Comparing

Reliably estimating soil vertical compression under vacuum loading is still challenging for geotechnical engineers. In this paper, the soil vertical compression within the prefabricated vertical drain (PVD)-improved zone under vacuum pressure was investigated based on the theoretical analysis, reported laboratory tests and the case histories. A theoretical equation was developed to evaluate the effect

A scaled plane-strain shaking table test was conducted in this study to investigate the seismic performance of a Geosynthetic Reinforced Soil-Integrated Bridge System (GRS-IBS) with a full-length bridge beam resting on two GRS abutments at opposite ends subjected to earthquake motions in the longitudinal direction. This study examined the effects of different combinations of reinforcement stiffness

Deep cement mixed (DCM) soil columns have been widely utilized to improve soft soil to support embankments or seawalls. However, the influence of the time-dependent behavior of the soft soil on the performance of DCM column-supported embankments is not well understood. In this study, the finite element (FE) model was established to investigate the creep effects on settlements and load transfer mechanisms

This study focuses on the stability of stone column-supported and geosynthetic-reinforced embankments on soft soil. An upper-bound limit state plasticity failure discretization scheme (known as discontinuity layout optimization (DLO)), which determines the embankment stability without pre-assuming a slip surface, is used. The relationships between the stability of stone column-supported and geosynthetic-reinforced

This paper presents a series of model tests on geosynthetic-reinforced soil (GRS) foundations across a normal fault. The aim was to evaluate the performance of reinforced foundations as a mitigation measure for surface faulting hazards. Experimental tests modeled a 3-m thick foundation in prototype subjected to a fault displacement up to 90 cm. Test variables included the number of reinforcement layers

To understand the structural behavior of geogrid reinforced soil retaining walls (GRSW) with a deformation buffer zone (DBZ) under static loads, the model tests and the numerical simulations were conducted to obtain the wall face horizontal displacement, vertical and horizontal soil pressures, and geogrid strains. Results showed that compared with the common GRSW, the horizontal displacement of GRSW

The paper proposes a new approach to use measured data of the constant strain rate test (CRST) for analysis of consolidation by prefabricated vertical drains (PVDs). Each PVD has an influence zone that idealised as a unit cell. Consolidation behaviour of a unit cell is studied with an axisymmetric finite element (FE) model based on Biot's theory. From a CRST data, ASTM-D4186 or the back-analysis method

The hydraulic and swelling properties of a polymerized bentonite (PB), and the self-healing capacity of a geosynthetic clay liner (GCL) using the PB as the core material (PB-GCL) were investigated experimentally. Five different test liquids included of deionized water, NaCl solutions (0.1 M and 0.6 M) and CaCl2 solutions (0.1 M and 0.6 M) were used in this study. The PB exhibited a higher free swelling

This paper reports full scale experiments, under simulated heavy traffic, of geocell and EPS (expanded polystyrene) geofoam block inclusions to mitigate the pressure on, and deformation of, shallow buried, high density polyethylene (HDPE) flexible pipes while limiting surface settlement of the backfilled trench. Geocell of two pocket sizes and EPS of different widths and thickness are used. Soil surface

The seismic internal stability of reinforced, convex embankments that are three-dimensional in nature is analyzed. A limit equilibrium based three-dimensional rotational failure mechanism is adopted to calculate the required reinforcement strength to maintain the stability of convex embankments. The results are presented in the form of stability charts and the effects of various parameters on the three-dimensional

This research was conducted to investigate the shear strength at the interface between polymer concrete and asphalt concrete with geotextile as reinforcement at the interface of these two types of concrete. The samples were tested for the parameters of different surface conditions [rough and smooth], curing types [room and thermal curing], temperature effect and the impact of geotextile as reinforcement

For over fifty years, geosynthetics have been used for land reclamation of degraded areas. Several years ago for this purpose innovative geotextiles formed from meandrically arranged thick ropes were invented. The geotextiles were used for reclamation of abandoned lignite open-mine in Germany and disused gravel pit in Poland. The geotextiles were installed in abandoned mines. In next years positive

Clogging effect surrounding prefabricated vertical drains (PVDs) is a typical problem when vacuum preloading is applied to a dredged fill foundation. A large-scale model test was designed to clarify the cause and mechanism of the clogging effect, and the basic physical and mechanical parameters of the soil in the clogging zone were tracked during the test. The results demonstrated that a clogging zone

The seismic performance of soilbags-built retaining wall model was studied experimentally. A series of small-scale shaking table tests with the input of different amplitude sinusoidal waves and a large-scale shaking table test in a designed laminar shear box with the input of the Wenchuan earthquake wave were carried out on soilbags' retaining wall models. For comparison, the small-scale shaking table

Although natural fibers can improve the strength behavior of frozen-thawed soil, the reinforcing mechanism is still not fully understood. To investigate the effects of freeze-thaw cycles on the strength of natural fiber-reinforced soil, unconfined compression tests, single-fiber pull-out tests and scanning electron microscopy (SEM) tests under 0, 3, 5, 10, 15, and 20 freeze-thaw cycles were conducted

Fine-grained dredged sediments can be efficiently and sustainably handled by hydraulically filling containment facilities, which can then be reclaimed. This study presents two numerical modelling strategies, characterized by markedly different levels of complexity, that simulate the gradual filling and subsequent consolidation process. Both numerical models employ hydro-mechanical constitutive relations

The aim of this paper is to study the performance of plasticised polyvinyl chloride (PVC) geomembranes used in the rehabilitation of concrete and masonry dams. In such applications, the geomembranes are left exposed on the upstream face, without external protection, to environmental factors and weather conditions, especially to UV rays. Evaluation of the performance and the lifetime assessment of the

The behaviour of geosynthetic clay liners (GCLs) as part of a physical-environmental system is examined. Consideration is given to: (a) both the physical and hydraulic interactions with the materials, and the chemical interactions with the fluids, above and below the liner, (b) time-dependent changes in the materials, (c) heat generated from the material to be contained, as well as (d) the climatic

A GeoBarrier system (GBS) is a combination system of reinforced soil walls to stabilize near-vertical cut slopes and capillary barrier principles to protect the wall from the effect of rainfall infiltration. Singapore requires construction materials that are cost-effective to support sustainable urban development. Therefore, recycled materials are utilized as GBS materials to avoid the use of high-cost

Depletion of antioxidants in HDPE subjected to sunlight exposure was studied. Sunlight radiation was simulated using a laboratory xenon light weatherometer at three irradiation levels. Oxidative induction time (OIT) test was performed on different layers along the thickness of the test coupons to establish the antioxidant depletion throughout the exposure duration. The highest drop in OIT was obtained

This study investigates how the shear rate can affect the geomembrane – protective geotextile friction angle. Four types of geomembranes (GMB) were considered (EPDM, HPDE, PP, and PVC) and a single nonwoven needle-punched geotextile (GTXnw) was used to make the interfaces with the geomembrane. Three shear devices were used: a large-scale inclined plane (IP), a shear box (SB), and a small-scale shear

In this paper, shaking table tests were carried out on both a small-scale and a full-scale earth-fill dams with geosynthetic clay liners to examine their seismic performance. The behavior of these fully instrumented earth-fill dams when subjected to seismic loading was also simulated by numerical analysis. Firstly, in the small-scale shaking table test, no failure was observed along the geosynthetic

Tire derived aggregate (TDA) is currently being used as a cost-effective substitute for gravel in landfill leachate collection systems. TDA is composed of tires that have been shredded into pieces. However, the particles often contain a small portion of high risk protruding wires that may puncture a geomembrane placed below the TDA. The chance that these wires puncture is a function of the number of

The discharge capacity of a tunnel drainage system generally decreases with time because of the hydraulic deterioration of the geotextile filter. Hydraulic deterioration restricts groundwater flow into a tunnel and increases water pressure resulting in detrimental effects on the tunnel lining. Hydraulic deterioration of tunnel drainage system is unique in terms of clogging materials, deterioration

This paper examines the effect of the mobilized reinforcement tension within reinforced soil slope at a different level of soil-geosynthetic interaction. The mobilized reinforcement tension is assumed, in most design methods for the internal stability of reinforced slopes, to be equal to mobilized soil forces computed using a limit equilibrium method. However, comparison with the reinforcement tension

The effectiveness of the prefabricated vertical drains (PVDs) in the consolidation of ultra-soft dredged soil with various soil water contents (W) in Mae Moh mine, Lampang, Thailand was researched via a series of large-scale model tests and numerical analysis. Large settlements with the delay of excess pore pressures is a distinct behavior of ultra-soft soil. The PVD dimensions were found to have a

This paper presents the performance monitoring results and long-term numerical analyses of a 2.8-m-high test embankment with vertical drains on soft highly compressible clays during a four years and two months observation period (1525 days). The peculiar study site is characterized by thick layers of lacustrine soft clay with water contents up to 300%, void ratios between 7 and 9 and ratios Cα/Cc range

In sulfate-rich soils with high sodium sulfate contents, sulfate heave can occur and then generate severe damages to engineering facilities such as pavement, airplane runway due to the hydration of thenardite or crystallization of mirabilite when the temperature is below 32.4 °C. Based on the significant effect of expanded polystyrene (EPS) geofoam in reducing the temperature variations, a comparative

This paper presents a new geosynthetics isolator composed of stacked sandbags for buildings’ base-isolation method to improve human comfort under subway-induced environmental vibrations. The static and dynamic mechanical properties of the isolator are tested in a laboratory first. Then field experiments are performed with a full-scale building to investigate the effectiveness of the isolator. The results

This study numerically investigates the behaviour of a geosynthetic-reinforced soil (GRS) wall under surcharge loading. Data from a full-scale GRS physical model wall was used to verify the numerical analysis. The modelling was carried out using the two-dimensional finite difference computer program FLAC to verify the post-construction performance of a full-scale GRS segmental wall under surcharge

The improvement efficiency of a dredged slurry by vacuum preloading is greatly affected by the apparent clogging effect arising during the consolidation process, where the apparent clogging effect refers to the combined impacts of filter clogging and particle blinding around the drain due to particle migration and non-uniform consolidation. Three laboratory model tests with different types of soils

The behaviour and performance of different reinforced slopes during earthquake loading were investigated through a series of shaking table tests. Concrete-canvas and composite reinforcement (geogrid attached to concrete-canvas) were proposed for reinforcing slopes. By considering the effects of different reinforcement methods, the seismic responses of the reinforced slopes were analysed, along with

Air booster vacuum preloading is a newly improved method applied in land reclamation projects. Highly pressurized air can provide an additional pressure difference between the prefabricated vertical drain (PVD) and injection point, thereby increasing the hydraulic gradient and generating small fractures that can improve the soil permeability and the transmission efficiency of the vacuum pressure. However

Resistance to oxidation of a polypropylene (PP) woven geotextile was determined by performing and evaluating various high-pressure autoclave tests (HPAT). Unlike that proposed in the corresponding ISO standard and the majority of HPAT studies published, tests were performed at slightly elevated oxygen pressures (pO2) of up to 500 kPa. Extrapolations were carried out with regard to temperature and oxygen

Geosynthetics have been widely applied in flexible pavements for decades. However, the mechanistic-empirical analytical approach for geosynthetic-stabilized flexible pavements based on the elastic solution derived from the layered elastic theory has not been established. In this study, the solution for a typical three-layer geosynthetic-stabilized flexible pavement was derived according to the layered

This paper presents the results of laboratory model tests carried out on two closely-spaced interfering footings resting on the surface of geogrid-reinforced and unreinforced sand bed. The effect of aspect ratio (or shape) of the footing on interference behavior is studied by adopting three pairs of model footings of different sizes. The length (L) to width (B) ratio (i.e., aspect ratio) of the footings

This paper presents the results of a laboratory investigation into the behavior of a geosynthetic encased stone column (GESC) installed in sand under cyclic loading using a reduced-scale model. A number of test variables were considered, such as the geosynthetic encasement stiffness and the cyclic loading characteristics, including loading frequency and amplitude. The results indicate among other things

The assessment of the internal stability of geosynthetic-reinforced earth retaining walls has historically been investigated in previous studies assuming dry backfills. However, the majority of the failures of these structures are caused by the water presence. The studies including the water presence in the backfill are scarce and often consider saturated backfills. In reality, most soils are unsaturated