Geotextile Layer Research Articles

An evaluation of square footing response on lime-treated geotextile-reinforced silty sand: contrasting experimental and computational approaches

Improving soil strength and reducing the anticipated settlement and construction cost is a great paradox for civil as well as geotechnical engineers. In this paper, these aspects and other suitable types of ground improvement are discussed based on the principles of using geosynthetics for soil reinforcement. A series of load-settlement tests were also performed to compare strength and settlement of the silty sand reinforced with lime and one layer of geotextile. The study finds the maximum insertions of geotextile at 0.2D (3.0 cm) beneath the square footing base, and the lime percentage of 5.0% increases the UBC substantially. The UBC of lime-treated and geotextile-reinforced silty sand was to an optimum of 1,360 kN/m2 that has shown an enhancement of 258% compared to that of untreated and unreinforced silty sand that is approximately 380 kN/m2. Furthermore, comparative analysis between two ANN models was performed to provide improved estimate of the UBC, namely artificial neural network (ANN) and extreme learning machine (ELM). The developed computational models were then compared with experiment data, which proved that such models are more economical and effective than the expensive and time consuming conventional techniques. Consequently, based on the results, it was further validated that ELM possesses better generalization capability compared to ANN for predictive efficiency and thereby proves the efficiency of the model in estimating the ultimate bearing capacity of square footings incorporated with geotextile and lime-treated silty sand. This places the ELM model as a useful tool in the initial conceptual as well as the design for improvement steps of soil reinforcement.

Experimental Investigation of Embankment Wedge Failure’s Stability under the Effect of the Number and Spacing of Geotextile Layers in the Reinforced Retaining Wall

Experimental Investigation of Embankment Wedge Failure’s Stability under the Effect of the Number and Spacing of Geotextile Layers in the Reinforced Retaining Wall

Study on the formation and dewatering process of the surface filter cake of geotextile on the lateral boundary of geotextile tubes under constant flow grouting

In this article, physical model test and numerical simulation are used to study the formation of filter cake and the filtration performance of the geotextile on the lateral boundary of the ultra-fine tailings grouting geotextile tubes from macro and micro levels. At the macro level, the effects of different grouting flow rates and tailings slurry mass concentrations on the surface filter cake formation and the dehydration performance of geotextile on the lateral boundary of the geotextile tubes were analyzed. At the micro level, the use of CFD-DEM method for fluid and particle of two-way coupling numerical simulation research, lateral drainage boundary of superfine tailings in tubes filter cake forming process is analyzed. The research shows that the increase of grouting flow rates and tailings slurry mass concentrations will make the thickness of filter cake great and the structure more compact, which will lead to more serious silting of the surface layer of geotextile and greatly reduce the dehydration performance; The numerical simulation results regularity is consistent with the results regularity of physical model test on the formation of filter cake on geotextile surface of geotextile tubes: the larger the slurry inlet speed and particles concentrations, the more complete the formation of filter cake on geotextile surface, the denser the cake structure, and the less tailings loss. By studying the effects of grouting flow rates and slurry mass concentrations on the surface filter cake formation and tubes dehydration, this article aims to find suitable slurry filling construction conditions and explore the main influencing factors caused by dehydration and consolidation of ultra-fine tailings grouting geotextile tubes, so as to provide some help for the subsequent flocculating of ultra-fine tailings to solve the problem of surface drying and internal wetting of geotextile tubes.

Assessing the key concerns in snow storage: a case study for China

Abstract. Snow security plays a crucial role in ensuring the success of winter sports events and supporting the ski industry. One effective approach to enhancing snow reliability is through snow storage. Despite its potential benefits, investigations of snow storage in China have been limited. To address this gap, we implemented snow storage covered with geotextiles at two venues, namely the Big Air Shougang (BAS) in Beijing for the Beijing 2022 Winter Olympic Games and the National Biathlon Center (NBC) in Chongli for the Beijing 2022 Winter Paralympic Games, in response to possible extreme meteorological conditions. To assess the key concerns associated with snow storage, ablation (the process of snow loss) and snow properties, we introduced a fine-snow-pile monitoring system and the SNOWPACK model. Our observations revealed that, by 18 February, the snow pile at BAS had lost 158.6 m3 of snow (equivalent to 6.7 % of the initial volume). Subsequently, the accelerated ablation was influenced by meteorological conditions and a thin geotextile layer. Between 16 January and 15 April, the snow pile at BAS experienced a total loss of 1242.9 m3 of snow (corresponding to 52.7 % of the original volume). Regarding snow properties, no significant variations were modeled at the study sites, except for the upper part of the snow piles. Notably, the evaporation of the geotextiles contributed to slowing the ablation process. Consequently, we discourage the use of impermeable coverage schemes for snow storage. Instead, the thickness of the cover played a vital role in preserving the snow pile. At Beijing and Chongli, the 0.7 and 0.4 m thick cover layers, respectively, were found to protect approximately half of the snow pile height over the summer season. Importantly, the evolution of snow properties was consistent across the different cover thicknesses. The findings of our study have implications for the ski industry in China, as they provide valuable insights into snow storage techniques and their impact on snow reliability.

ANALISIS STABILITAS TIMBUNAN TANAH DENGAN PERKUATAN GEOTEXTILE MENGGUNAKAN SOFTWAREPLAXIS (Studi Kasus Pembangunan Jalur Ganda Antara Solo Balapan – Kadipiro - Kalioso)

This research aims to determine the stability of embankments without reinforcement and with reinforcement and the amount of settlement that occurs in accordance with the SNI geotechnical standard 8460 of 2017. The research location is in KM. 96 + 400 to 104 + 900 between Solo Balapan – Kadipiro – Kalioso. The analysis was carried out using Plaxis 2D Software version 8.6 without reinforcement, a safety factor value of 1.2 was obtained, where the result was below 1.5, which did not comply with the requirements of SNI 8460:2017 article 7.5.5. as well as a 30 day decline of 1,707 cm, a 100 day decline of 1.6 41cm and a 365 day decline of 1,691 cm. So it can be concluded that the embankment at that location is unstable. For this reason, additional geotextiles are added as reinforcement, after adding geotextiles. In the analysis of the embankment at KM 98 + 550 with the addition of embankment reinforced with geotextile, manual calculation results were obtained with a total of 5 layers of geotextile. The minimum geotextile length is 2.338 m and the stability of the bearing capacity is SF = 4.37 > 1.5. For embankment analysis at KM 98 + 550 after adding geotextile reinforcement. After adding alternative geotextile reinforcement, it was found that the safety factor value increased to 1.7, where this value was greater than 1.5 as indicated by SNI 8460: 2017 article 7.5.5, while the decrease at 30 days was 1,056 cm, the decrease at 100 days was 1,056 cm, and the decline in 365 days was 1,056 cm, so it can be concluded that the embankment at that location is considered stable.

Enhancing clay soil stability in seasonal freezing areas through waste cherry marble powder and geotextile reinforcement

In this study, the mechanical and durability performance of clay soils reinforced with different proportions of Cherry Marble Powder (CMP) and non-woven geotextile configurations, both independently and in combination, is investigated in detail at both the macro and micro levels. The effectiveness of reinforcement in the stabilization of clay soils in cold climates has been evaluated by means of Gray Correlation Analysis (GCA). The results show that as the CMP ratio and the number of geotextiles increase, the peak strength of the soil increases, with higher CMP levels showing perfect plastic behavior and more geotextiles showing linear strain hardening, particularly in combination. Substantial strength reductions post-7th cycle ranged between 91.09 % and 103.38 % for 12 % CMP and 219.83 % and 270.42 % for three-layered geotextile groups. Cohesion increased by 59.76 % and 179.41 %, while the internal friction angles remained stable and decreased after F-T cycles, except with additives. Failure modes shifted with CMP content, F-T cycles and confining pressure. The transition was from strain hardening to strain softening, with increased shear fracture planes and brittleness. The energy absorption capacity (EAC) increased with the CMP ratio, with the geosynthetic reinforcement increasing the EAC by a factor of 1.5 before and after the F-T cycles. The combined use of CMP and geotextiles in soil stabilization improved the engineering properties in areas of frost, with the optimum gradation being three layers of geotextile and a CMP ratio of 12 %, which effectively mitigated the effects of the maximum F-T cycle.

Numerical analysis of soil–steel composite structure performance at ultimate load: impact of stiffening ribs and geotextile reinforcement

This study investigates soil–steel composite structures, emphasizing the role of stiffening ribs and geotextile reinforcement through comprehensive numerical modeling. This study presents a two-dimensional finite element analysis (FEA) and compares the influence of stiffening rib and geotextile on the ultimate bearing capacity of the soil–steel composite structures. The results of this study demonstrate a significant enhancement in load capacity. Specifically, a notable 47% improvement was observed with a stiffening rib, and a 26% increase was noted with the use of a single layer of geotextile. Under peak load, the vertical displacement at the crown exceeds the permissible standard for all models except for one model, while bending moments reach their limits, marking a failure mode of composite system considered. Structures with stiffened ribs reach their load capacity due to the creation of a plastic hinge around the shoulder and haunch of the shell. On the other hand, in structures without stiffening ribs, the crown and haunch section of the shell becomes fully plastic under peak load. The maximum axial thrust is shown in geotextile-reinforced structure, reaching 78% of the shell maximum capacity due to compression. Eventually, stiffening rib substantially improves overall load-bearing capacity of the soil–steel composite structures, and geotextile placement in the upper part of the backfill reduces shell deflection due to bending.

Experimental evaluation of performance of geo-mat system on weak to intermediate subgrade

Geo-mat system is considered as an alternative to a flexible or rigid pavement that can be used for fire lanes, parking areas, or roadway shoulders for cars, pickup trucks, utility/delivery trucks, and fire trucks. Also, it can be used to reduce the thickness of the base course in unpaved roads. In this investigation, six cyclic loading tests were conducted to assess the efficacy of the geo-mat system on weak to intermediate subgrade layers, characterized by California Bearing Ratios (CBR) of 2%, 3%, and 4%. Control sections, consisting of a 300-mm thick base course over subgrade layers with CBR values of 2% or 4%, were compared against the test sections comprising a geo-mat system placed atop aggregates of varied thickness (150 or 50 mm) on a geotextile layer over the same subgrade layers. Each test section underwent cyclic loading, progressively increasing from 17.8 to 71.2 kN using a 300-mm diameter steel plate. The results demonstrate that the geo-mat system, particularly when placed over a 150 mm-thick aggregate base, exhibited comparable or superior performance to the control sections with a 300 mm thickness, especially under substantial cyclic loading. This was evidenced by the reduced permanent deformations beneath the loading plate and a wider load distribution. The increase of the subgrade CBR value reduced the permanent deformation significantly. When the intermediate subgrade with a 4% CBR was used, the geo-mat system played a more important role than the aggregate base and the base thickness had a minor effect on the performance.

LANDFILL STABILITY ANALYSIS USING CORRUGATED CONCRETE SHEET PILE (CCSP) WITH PLAXIS 2D V22 SOFTWARE

Landfill in road projects requires a stable condition before it can be continued on further work. The stability factor of the landfill depends on the bearing capacity of the subgrade, the shear strength of the soil, the planned elevation, and the angle of inclination of the landfill. This research is located on one side of the Jagorawi Toll road and the Bogor Outer Ring Road, near the South Sentul Toll exit gate. The results of the soil investigation obtained a clay type soil classification at a depth of 0 – 13 m (N-SPT value 3-5). Initial analysis shows the need for landfill height, varies along the road (ranging 4.9 m - 2.4 m). The purpose of this research is to compare the stability of the landfill in the following 2 conditions, 1st condition from STA 1+789 – STA 1+850 (4.9 m height of landfill) using Corrugated Concrete Sheet Pile (CCSP) reinforcement on the left and right of the road side with a 2 m deep geotextile layer, and 2nd condition from STA 1+850 – STA 1 +950 (2.4 m height of landfill) does not use any reinforce. The research approach uses quantitative descriptive, research data including other soil classifications, bor logs, N-SPT values, soil properties from samples (C, Ø, γ, etc.) taken from the site. Apart from that, data on the geotextile and CCSP parameters that will be used is also needed. Analysis was carried out using the Finite Element approach and Plaxis 2D V22 software. The results show that in 1st condition, the safety factor value is 3.7, where the reinforcement system provided is able to withstand 3.7x the working load (vehicles and active soil). Meanwhile, on the 2nd condition produces a safety factor value of 5.2. The analysis results show that these 2 areas have a safety factor that exceeds the existing literature requirements, namely 1.5.

Removal and fate of microplastics in permeable pavements: An experimental layer-by-layer analysis

The increasing prevalence of microplastics (MP) in urban environments has raised concerns over their negative effects on ecosystems and human health. Stormwater runoff, and road dust and sediment, act as major vectors of these pollutants into natural water bodies. Sustainable urban drainage systems, such as permeable pavements, are considered as potential tools to retain particulate pollutants. This research evaluates at laboratory scale the efficiency of permeable interlocking concrete pavements (PICP) and porous concrete pavements (PCP) for controlling microplastics, including tire wear particles (TWP) which constitute a large fraction of microplastics in urban environments, simulating surface pollution accumulation and Mediterranean rainfall conditions. Microplastic levels in road dust and sediments and stormwater runoff inputs were 4762 ± 974 MP/kg (dry weight) and 23.90 ± 17.40 MP/L. In infiltrated effluents, microplastic levels ranged from 2.20 ± 0.61 to 5.17 ± 1.05 MP/L; while tire wear particle levels ranged between 0.28 ± 0.28 and 3.30 ± 0.89 TWP/L. Distribution of microplastics within the layers of PICP and PCP were also studied and quantified. Microplastics tend to accumulate on the pavements surface and in geotextile layers, allowing microplastic retention efficiencies from 89 % to 99.6 %. Small sized (< 0.1 mm) fragment shaped microplastics are the most common in effluent samples. The results indicate that permeable pavements are a powerful tool to capture microplastics and tire wear particles, especially by surface and geotextile layers. The study aims to shed light on the complex mobilisation mechanisms of microplastics, providing valuable insights for addressing the growing environmental concern of microplastic pollution in urban areas.

ANALISIS STABILITAS TIMBUNAN DENGAN MEMBANDINGKAN BRANKAL DAN GEOTEKSTIL

Construction activities in road infrastructure development are never separated from earthworks which often become obstacles due to differences in land contours due to excavation and embankment work which is closely related to geotechnical engineering. Embankment and excavation are very interesting things to study because they are closely related to slope safety factors and require special handling. In this research, we examine the use of geotextiles by comparing the handling using safes on embankment stability using PLAXIS Version 8.2 software. The results of embankment stability analysis with safes, settlement at 1 year consolidation was 5.6 cm and settlement at 10 years consolidation was 5.7 cm. in accordance with applicable criteria. The results of the analysis using 2 layers of geotextile showed that the settlement at 1 year consolidation was 4 cm and at 10 years consolidation was 4.1 cm, which is in accordance with the applicable criteria.. Meanwhile, the results of the slope safety factor using bract treatment at 1 year consolidation were 1.475 and the safety factor for 10 year consolidation was 1.478, not in accordance with the design criteria of 1.5. The results of the safety factor using 2-layer geotextile treatment at 1 year consolidation was 1.853 and the safety factor for 10 year consolidation was 1.855, which is in accordance with the design criteria of 1.5.

A circular economy approach for geotextile reuse following lake water filtration

Eutrophication in lake systems is intensifying. To reduce this possible scenario, a method for suspended solids and associated nutrient removal by a novel on-site remediation has been investigated, using nonwoven geotextiles as filter media. These procedures generate clogged geotextile layers with captured suspended solids on them. To become more sustainable, circular economy principles were employed, more precisely reuse. Thus, this investigation aims to assess the potential reuse strategies by washing clogged layers and determining their possible reuse. The washing method was pressurized water (i.e., using a gardening pump sprayer). Preliminary results have shown the efficiency of the washing method in removing visible geotextile (non-woven) clogging, with permeate flow rates reaching values close to the initial process values. The geotextile apparent opening size increased by an order of 20%. Also, no geotextile fibre disruption was observed by scanning electron microscope (SEM) imagery, indicating its possible reuse. The dilute liquid waste preliminary findings showed high concentrations of some metals such as manganese, (112.72 μg/L) and zinc (88.12 μg/L) in addition to phosphorus (120.18 μg/L) which requires additional studies. The washed geotextile leaching test did not indicate any contaminants in the permeate which would enable geotextile layer reuse for lake water filtration.

Geotextile Reinforcement Model Laboratory Test on Silt Soil

Merauke Regency is a lowland area that has soft soil which predominates. One of the methods to overcome the subsidence in silt soil, it is necessary to strengthen it by using geotextiles. The function of the geotextile is to hold the soil surface so that there is no subsidence in the soil. This study aims to determine the carrying capacity of silt soil before and after being given geotextile reinforcement.The study used an experimental method using the addition of Geotextile (non-woven type TS600) to strengthen the carrying capacity of silt soil. The silt soil carrying capacity test was divided into several variations, namely without using geotextile reinforcement and reinforced with 1 layer, 2 layers, and 3 layers of geotextile at a depth of 10 cm, 20 cm and 30 cm.The results of research conducted in the laboratory, the use of geotextile materials to increase the carrying capacity of silt soil has increased compared to the initial conditions. Soil without using geotextiles has a greater decrease, namely at a load of 5 kN there is a settlement of 20.3 mm. By using a single layer geotextile reinforcement material at a load of 5 kN there was a decrease of 10.97 mm, while using a two layer geotextile reinforcement material at a load of 5 kN there was a decrease of 8.09 mm, and using a three layer geotextile reinforcement material with a load of 5 kN there was a decrease of 6.01 mm. It can be concluded that the use of geotextile reinforcement can reduce the settlement of silt soil.

Experimental and Numerical Investigation of Geosynthetic-Reinforced Pile-Supported Embankments for Loose Sandy Soils

This research focuses on advancing the geosynthetic-reinforced pile-supported embankment technology over loose sandy soil. A small-scale laboratory model supported by floating piles and a geotextile layer was constructed, and a numerical model was validated against laboratory measurements. This study aims to achieve a more uniform distribution of the load over all piles of the system via a parametric study that analyzes the influence of embankment fill material, horizontal reinforcement scenarios, pile cap shape, and pile type. The results demonstrate that using embankment fill with high cohesion and internal friction properties leads to a significant reduction of 46% and 37% in maximum settlements, respectively, and similarly, results in a noteworthy reduction of 48% and 50% in differential settlements. The incorporation of two geotextile layers contributes to a reduction of up to 30% in maximum settlement. The utilization of plus-shaped caps in small areas, with an area equal to three times the cross-sectional area of the pile, has been substantiated as the preeminent approach for the reduction of settlements. Piles with caps also present better behavior regarding differential settlements compared to longer piles and piles with bigger diameters under the same volume condition.

Physical Modeling of the Effect of Using Scaled Geosynthetic Reinforcements on Bearing Capacity and Settlement of Strip Footing

This study evaluated the strip foundation bearing capacity and settlement on sandy soil reinforced with scaled geocomposite and geotextile by laboratory model testing. Therefore, several reinforcement compounds were used in different layers (one to four), including identical and various vertical distances from each other and the footing base. The geocomposite used in this study consisted of geogrid and geotextile layers. The most crucial consideration in this research was the application of scaled reinforcement with a factor of 7.5 to create more precise laboratory models. Based on the results, all models failed in the lower settlement, which in most cases was 7% of the width of the footing. Test results indicated that the maximum increasing factor in bearing pressure of foundation in the case of ultimate bearing was 3.4, which could be related to using four layers of geocomposite at optimal distances. The percentage of decreasing footing settlement at the maximum value was about 86% in the two-layer geocomposite state. Its value remained constant with increasing number of layers. Percentage variation in bearing capacity value indicated that geotextile had a better performance in increasing the bearing capacity at the high settlement level. It was close to the values of the geocomposite.

Experimental study on bulge deformation of geotextile under ring-restrained conditions

Geotextile layers are arranged on and below the geomembrane to prevent the geomembrane from being punctured and damaged. The geotextile not only plays a role in physical protection, like anti-puncture but also makes a great difference to the mechanical properties of the geomembrane’s air expansion deformation. In this paper, the bulging deformation of geotextile is simplified as spherical bulging deformation under ring-restrained conditions. Using the special bulging deformation test equipment, the bulging deformation experiment of geotextile is realized, the main factors affecting the bulging deformation are analyzed, the law of bulging deformation and failure of geotextile is summarized, the failure mechanism of geotextile and the Influence of geotextile on the properties of geomembrane are discussed, and the following conclusions are drawn. The failure of bulging deformation of geotextiles belongs to tensile failure, which is characterized by fast speed and high strength. The typical failure mode is spindle-shaped cracks distributed along the crown, whose failure mechanism belongs to tensile failure produced in weak areas. The bulging deformation of the geotextile shows nonuniformity, with the largest deformation at the crown top and the smallest deformation at the ring constraint. When the geotextile is covered on the geomembrane, bulging pressure is shared by both the geomembrane and the geotextile. At the initial deformation stage, the geomembrane replaces it, and then the geotextile bears more internal pressure and plays a decisive role till destruction.

Reducing Deep Percolation Losses Using a Geotextile Layer at Different Soil Depths and Irrigation Levels for Lettuce Crop (Lactuca sativa L. var. capitata) (Limor)

Due to rising food demand and the limitation of water resources, achieving water security is essential. The lettuce crop is affected when grown under limited water supplies as it produces small heads, especially during the late growing stage. For this reason, it is important to maximize water use efficiency and crop productivity. Two successive experiments were conducted during 2021 and 2022 to reduce losses via deep percolation using a geotextile layer at different soil depths under different irrigation levels of the lettuce crop (Lactuca sativa L. var. capitata). This study aims to reduce water losses due to deep percolation and improve crop growth and yield parameters for iceberg lettuce under subsurface drip irrigation in sandy loam soil conditions. In order to achieve these aims, different amounts of irrigation (100, 80, and 60% of crop evapotranspiration “ETc”) and a geotextile layer at different soil depths (20, 30, and 40 cm from the soil surface) were used. The results revealed that the use of a geotextile layer with 20 and 30 cm depths significantly improved irrigation application efficiency and noticeably increased soil water content in the root zone. The observed results during both seasons showed that geotextile layers at 20, 30, and 40 cm depths under irrigation of 100% ETc significantly increased vegetative growth characteristics (plant height, head diameter, head circumference, head volume, plant fresh weight, and leaf area) and crop productivity compared to the control (without geotextile). In particular, the geotextile layer at a 30 cm depth under irrigation of 100% of ETc was the most statistically effective treatment in this study, with yield values of 69.3 and 67.5 t ha−1 in the two seasons, respectively. However, the treatments of geotextile layers at 20 and 30 cm depths under irrigation of 80% of ETc also recorded statistically effective results for crop growth parameters and yield in this study. In general, geotextiles can be used at different depths as an irrigation management practice to reduce deep percolation in the field.

Model study on geotextile reinforced railway subgrade

The high speed trains in railway infrastructure impose high level of stress in the railway subgrade. In order to have high bearing capacity, for the construction of railway subgrade, high strength materials should be used. In the present study the railway subgrade with layers of geotextile is proposed. CBR test has been carried out at OMC and soaked conditions. Samples have been prepared by static compaction and the experiment has been carried out for five types of samples with reference to geotextile layer placement in the mould. A load vs. settlement curve has been plotted for each case mentioned above. Then a graph is drawn in order to study the variation of CBR value with number and location of geotextile layer. The purpose of CBR test has been to study the effect of location and number of geotextile layer on CBR value of subgrade soil. A model box of size 1 m × 1 m × 1 m has been constructed from steel sheets. A simple hydraulic jack loading system manually operated with a calibrated proving ring of capacity 5000 kN has been used for loading arrangement. The silty sand was placed in the box in three layers, each being 12 cm thick and compacted at OMC. The base course (aggregate size 20 mm) and sub-base course (aggregate size 40 mm) was of 7.5 cm each. The plate used for applying load is of mild steel with 20 cm diameter. Load is applied by jack and settlement was observed by dial gauge. The plate bearing test has been carried out on model subgrade section.

Improvement of Subgrade CBR Using Geotextile

The main purpose of our project is to test the improvement in the CALIFORNIA BEARIBG RATIO of SUBGRADE SOIL upon usage of GEOTEXTILE layer in the soil. We planned to test the effect of geotextile under different conditions of placement height, soil characterstics and moisture content. We performed experiments in the laboratory to determine the results and variation of CBR value and plotted it to draw inferences. Key Words: CBR, Geotextile, Subgrade, Moisture Content, Silty soil, Sandy soil.

Investigation the effect of geotextiles on the absorption of oil contamination and soil geotechnical properties

Oil-contaminated soil is detrimental to the ecosystem. There are various methods for purifying and controlling oil-contaminated soil. Among these, the use of oil absorbent geotextiles is considered a new method, and its performance requires more research. The separating by geotextiles has the advantages such as absence of chemicals in the separation process, less energy, simple control and implementation. This study presents an environmentally friendly sustainable solution using spacer geotextile layers to absorb crude oil and improve the geotechnical properties of contaminated soil. The variables include contamination percentage, number of fibrous substrate layers, soil overhead load pressure and duration of exposure to contaminated soil. The response variable is the internal friction coefficient of soil obtained from the direct shear test. By comparing soil samples containing geotextiles with samples without geotextiles, it was concluded that spacer geotextile layers could increase the internal friction coefficient of the soil and thus lead to improved soil properties. Increasing the number of geotextile layers, loading and the presence time of geotextile layers in the soil had increased the internal friction angle. But as the oil percentage in the soil increases, the internal friction angle of the soil decreases. Also, in this study, a linear regression model has been used to investigate the effect of existing parameters and the model was in good agreement with the experimental data.