Geotextile Materials Research Articles

Research on the performance and application of waterproofing materials in tunnel engineering

Abstract With the rapid development of highway transportation, the volume and construction difficulty of tunnel engineering have been increasing year by yea. Many engineering problems are difficult to solve, among which leakage is one of them. Tunnel waterproofing materials are an important component of controlling leakage and ensuring the safety and reliability of tunnel engineering. This paper provides the types, characteristics, and applications of tunnel waterproofing materials in tunnel engineering. The classification of tunnel waterproofing materials is introduced, including grouting materials, geotextile materials, and waterproofing board materials. Then, the characteristics of each type of material are elaborated in detail, including durability, constructability, and environmental friendliness. Finally, combined with actual engineering cases, the application of these tunnel waterproofing materials in tunnel engineering is discussed. This paper aims to provide a reference for the design and construction of tunnel engineering, and to provide a theoretical and practical basis for the research and application of tunnel waterproofing materials.

Effects of Filter Material on the Permeability of Sapric Peat in Flexible Wall Permeability Tests

Introduction Installation of Prefabricated Vertical Drains (PVDs) is one of the alternatives for ground improvement used in peatland deposits. However, filter paper is commonly used as standard filter material to determine the permeability of peat rather than the PVD material itself. Aims This paper presents preliminary data on the effect of using two different filter materials on the permeability behavior of Sapric peat. Methods A series of flexible wall permeability tests (FWPTs) was conducted to evaluate the peat permeability behavior under compression using two filter materials. This study compared Whatman standard filter paper and Prefabricated Vertical Drain (PVD), which is a non-woven geotextile filter material. Results The results showed that both tests using filter paper and a PVD filter exhibited a high initial coefficient of permeability, which depends on the hydraulic gradient. The coefficient of permeability significantly decreased until a certain period and then diminished with time. The coefficient of permeability from PVD filter tests was found to be approximately 2.6 times higher than that of the standard filter paper under the same compression. The duration required to reach a semi-steady state flow condition from the PVD test was 0.9 times faster than the standard filter paper. The random error of the coefficient of permeability data from the tests using the PVD filter was lower than the data of the standard filter paper. Conclusion This preliminary result suggests that standard filter material might not represent the actual coefficient of permeability of Sapric peat. The coefficient of permeability value was less consistent compared to the PVD filter. The selection of filter material plays a crucial role in ensuring accurate and reliable results, especially when dealing with PVD construction in peat. Using the PVD filter in FWPT appears to be suitable for the design of PVD in peat. The findings of this study contribute to evaluating the correct parameters for engineers to design and analyze the effectiveness of the ground treatment method using PVD in peat.

Evaluation of the Tensile and Puncture Properties of Geotextiles Influenced by Soil Moisture under Freezing Conditions.

Freezing conditions under different humidity will influence the mechanical properties of geotextiles, leading to the gradual fracture of geotextiles. It brings hidden danger to the whole isolation, reinforcement and protection of rock and soil. It is particularly important to study the tensile and puncture properties of geotextiles considering low temperature and moisture content. In this paper, a series of tensile and puncture tests of geotextiles are performed under different low temperatures (0, -3, -6, -9, and -12 °C) and at different moisture content levels (0, 5, 10, 30, 50, and 80%). From the microscopic perspective, the failure mechanism considering the low temperature and moisture content was explained comprehensively. Experimental results indicate that with a decrease in freezing temperature, the tensile strength of geotextiles increases as a parabolic function while the elongation at failure decreases as an exponential function. Additionally, the puncture strength of geotextiles presented a parabolic increase with the decreasing temperature. Under the freezing temperature environment, the higher moisture content of geotextiles can generate a higher puncture strength increment. This research contributes to a more comprehensive understanding of the tensile and puncture properties of geotextile materials considering low temperature and moisture content. It can provide important guidance for the design of slopes, the reinforcement of earthen dams, and roadbed reinforcement with geotextiles in cold regions.

Bearing Capacity of Soft Clay Reinforced by Geotextile and Woven Bamboo

Bearing capacity is a value used to determine the ability of soil to withstand the pressure and load of a construction. One of the methods to increase bearing capacity of soft clay soil is use geotextile material as reinforcement material. The use of geotextile requires high operational costs, so it needs alternative replacement materials with lower prices and easily available, one of which is woven bamboo. The soft clay soil came from Purwosuman Village, Sidoharjo District, Sragen Regency, Central Java with a planned water content of 60.00% and was saturated. The parameters studied were the effect of depth variation using a footing width ratio of 100 mm (B) there are 0.5B, 1B, 1.5B, and 2B accompanied by the width of reinforcement at each depth variation based on the theory of pressure distribution in the soil 2 Vertical: 1 Horizontal. This study conducted physical properties of soil and loading frame testing. Based on the test, the maximum load retained by the soil with reinforcement is greater than the soil without reinforcement by 2455.71%. From the results of the analyses reviewed, the greater the dimension of the reinforcement width, the greater the maximum load value that will be able to withstand.

Village road restoration in electrical steam power plant area in Banten, Indonesia through embankment reinforcement using geoframe technology

This paper presents a case study of the restoration of village road located between Zone 2A and Zone 2B after the excavation for box culvert underneath it. Geotechnical investigations showed that the area will be constructed upon volcanic rock material. The height of the Geoframe is approximately 19.7 meters. This system is a combination of polyester strip for reinforcing element and connected with clamp to the facing made of galvanized steel as a permanent formwork and non-woven geotextile material for filter element. The inclination of Geoframe structure can reach almost vertical with over 85⁰ inclined facing. The result of this work, Geoframe’s facing can be grown with vegetation (grass) to accentuate a natural and green structure. From design perspective, the embankment safety factor was above the criteria stated in Indonesian National Standard for Geotechnical Design Requirements which is above 1.50 and design with pseudo-static earthquake load which is above 1.10. The system has proven to be easy to implement in the field, fast and can be carried out with good quality control.

Comparative Experimental Study of Geotube Groins and Mixed Clay–Geotube Groins under Various Flow Conditions

During the cofferdam construction of the toe reinforcement project at the Qiantang River Estuary, the scouring of the riverbed at the groin head often led to the collapse of geotube groins due to strong tidal currents. Based on field experience, employing a combination of clay and geotubes proved to be a more effective solution to this problem. This study adopted a flume model experiment to investigate the scouring and deposition around geotube groins and mixed clay–geotube groins. The results indicated that the influence of tidal surges on geomorphic changes surrounding the groins was more pronounced during spring tides than during neap tides. Under the same flow conditions, the scour depth at the head of the geotube groin was notably deeper than that of the mixed clay–geotube groin. Additionally, sediment silting behind the mixed clay–geotube groin was significantly greater than that behind the geotube groin. The clay component of the mixed clay–geotube groin served to mitigate the head scour, enhancing the overall structural stability to a certain extent. The geotube groin, with its surrounding scour pits expanding over time, experienced increasing tensile strain. This resulted in the rupture of the geotextile material, the loss of internal sand and, ultimately, groin collapse. It was found that mixed clay–geotube groins were better suited for cofferdam construction in strong tidal estuaries compared to geotube groin alternatives.

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 studies of reinforced clay bases of logging roads

The construction and operation of logging roads often takes place in unfavorable engineering and geological conditions. Very often, clayey soils with poor physical, mechanical and strength characteristics lie in the bases of logging roads. Improving these soil characteristics is an urgent task. For this purpose, reinforcement of soil bases with the help of geotextile materials is used. Most often, a horizontal arrangement of reinforcing geosynthetic layers is used. To date, there are a large number of studies of reinforced soil structures of logging roads, but they mainly concern the use of geosynthetics in sandy soils. Research in clayey soils is not enough. Therefore, experimental studies of the operation of reinforced foundations in clayey soils were carried out. The paper presents the results of stamp tests of clay soils reinforced with horizontal reinforcing layers. The studies were carried out in two stages. At the first stage, stamp model studies were performed, which made it possible to establish the optimal designs of reinforced clay bases. Based on the results of this stage, a single-layer horizontal reinforcing layer of geosynthetic material with a tensile rigidity of 2100 kN/m, an outer diameter equal to three stamp diameters, located at a depth equal to 0.25 stamp diameters was selected. The base soil was soft plastic clay. At the second stage, field stamping tests of the reinforced and non-reinforced clay base were performed. To study the stress-strain base, pressure sensors were selected to measure vertical normal stresses and a measuring system for their registration. Vertical displacements at various points of the active zone of soil foundations were evaluated by soil marks having a wire connection with deflection meters. The results of stamp tests showed that the bearing capacity of the reinforced base is 1.5 times higher than the bearing capacity of the unreinforced base. The deformation modulus of the reinforced base is 1.18 times higher than the unreinforced base in the load range from 0 to 100 kPa. The reinforcing layer is included in the work when the precipitation of the stamp is more than 30 mm. The stress-strain state of a reinforced base has significant differences from an unreinforced one. The reinforcing layer significantly reduces vertical stresses in the upper part of the active zone of the base, by an average of 22%/. The experimental stamp tests carried out made it possible to obtain a qualitative and quantitative picture of the operation of reinforced clay bases of logging roads.

О надежности бесполостного дренажа

Purpose: Based on the analysis of the performed theoretical, laboratory and field studies of cavityless drainage, both the authors of this article and other researchers established the conditions for ensuring the reliability of its operation during the standard service life. Methods: analysis of the causes and quantitative assessment of the entry of silting particles into the pores of drains from the soil surrounding the drain showed, that in the case of protection of drains from silting with geotextiles, the inflow of particles smaller than 0.05 mm is due to the fact that such particles are colmatizing and geotextiles, in accordance with the requirements for it, must pass them. Another source of their entry is the possibility of formation of filtration deformations at the contact of the drain filler with the surrounding soil when the filtration flow reaches velocities exceeding the erosive ones. Geotextile materials, which are widely used as protective and filtering materials, must pass water into the drainage in the spring, even while still in a frozen state. Results: it has been established that in the laminar regime, filtration deformations in cohesive soils at the contact of the filler with the soil surrounding the drain do not occur in the absence of vibrodynamic loading. In cavityless drainage used in industrial and civil construction, as well as in the case of draining agricultural fields, clogging particles let through by geotextiles reduce the cross-sectional area of drains by no more than 10%. When draining the railway subgrade by pipeless drainage, it is not advisable to protect the drain filler from above. At the same time, the height of the silted part of the drains does not exceed 10 cm for 100 years, which must be taken into account at the design stage. In the case of using geotextile materials as protective and filtering materials, their water loss coefficient μ should be ≥ 0.65 with porosity ≥ 0.8.

Prediction of non-woven geotextiles’ reduction factors for damage caused by the drop of backfill materials

The need for sustainable solutions in geotechnical works has encouraged the investigation of recycled construction and demolition wastes (RCDW) as backfill material. The possible damages caused by the launching (dropping) process of this “new” backfill material (RCWD) must be quantified for its combined use with geosynthetics. This study evaluated the influence of the backfill's grain-size distribution and the geotextile's mass per unit area in the damages caused by the launch of RCDW material and aimed to provide a prediction equation of the reduction factors. Five RCDW materials were launched from 1.0-m and 2.0-m height over five non-woven polyester needle-punched geotextile and specimens were exhumed to be tested under tensile. Databases were created with the results and subjected to machine learning to obtain a prediction equation for the reduction factor's values. The results show that the damages caused by the dropping height are complex. The 1.0-m increase in the drop height and the increase in the geotextile's mass per unit area cannot be associated with an increase in the damage. The geotextiles were more affected by the backfills with uniform gradation. A reduction factor's prediction equation is presented considering the three variables investigated (geotextile, drop height and backfill material classification). The artificial neural network is a more interesting solution than multiple linear regression since it does not possess several application criteria and provides more accurate predictions.

Design of large geotextile mat cofferdam over deep soft clay

This article describes an extensive investigation of the failure mechanisms of a large geotextile mat cofferdam over a deep soft clay layer, where the large geotextile mat was filled with sand. Finite element (FE) analysis was conducted to provide insight into the behaviour of large geotextile mats. The FE results were validated against 1 g model test data and centrifuge test data prior to undertaking a detailed parametric study. It is found that large geotextile mat cofferdam over deep soft clay has two distinctive types of failure mechanisms – global and local failure mechanisms. The global failure mechanism showed the whole dam sank downwards together, and the local failure mechanism included a central standing ridge with two dam sides sliding downwards. A formula, based on the results of the parametric study, was proposed to distinguish the potential failure mechanism of the dam and the foundation soil. For these two different failure mechanisms, both limiting fill height and safety factor of the dam could be predicted using the equations obtained from this study. Finally, a design framework was proposed to provide guidance for designing the large geotextile mat cofferdam over deep soft clay under construction.

Reliability of Soil and Ground Improvement Techniques in Niger Delta Region of Nigeria

This research work presents a study of the reliability of ground improvement methods in three states of the Niger Delta Area of Nigeria namely: Rivers, Bayelsa and Akwa –Ibom states. Natural soil which is peaty clay in nature was obtained from different locations in the area of study and improved with different percentages of chemicals, cement, ranging from 2% to 10% and geotextile materials after which reliability analysis was carried out on them for CBR and UCS tests. Results show that geotextile materials are not suitable for improving the peaty clay soils in the locations under study due to poor values of reliability while the reliability values obtained for soil improved with cement increases with increase in percentage addition of cement and curing period. Reliability values for soil improved with chemicals shows some variability but increase as curing period increases at percentage addition of chemicals from 2% to 6% for Calcium Oxide, Calcium Chloride, Calcium Hydroxide and Aluminium Hydroxide before a decrease in value. Sodium silicate reliability peaked at 8% while the optimal value of reliability for cement was realised at 10%.

An overview of water proofing system in concrete structures

Water Proofing is one of the methods to prevent leakage problems in buildings. For toilets, terraces, water tanks, and outdoor spaces, several methods of water proofing are suitable. Due to the concrete's tendency to shrink, fractures typically occur in the screed of the roof. However, the surface fracture will be partially repaired by casting the concrete in panels. This also happens due to temperature variation. Crystalline admix water proofing with water stops, water proofing with Atactic Polypropylene membrane, and injection are the water proofing systems most commonly used in basements. Using non-shrinking cementitious grout for waterproofing, concrete must have crystalline admixtures made of cementitious powder and water. For toilets in non-sunken places, water proofing with an elastomeric cementitious coating is used. In sunken areas, brick jelly cement concrete with inherent water proofing compound is used. Waterproofing without insulation and waterproofing with insulation are typically used in terraces. There are typically two different types of buildings: Air-conditioned buildings and Non Air-conditioned buildings. Buildings with air conditioning need to be insulated. Extruded polystyrene with geotextile mat is used as over deck insulation. Injection grouting is used in water tanks on the side walls and base slab. On the top surface of the slab and the outside face of the wall throughout the whole area, holes must be drilled using a pneumatic hammer in a zigzag pattern. Generally artificial area and extended basement needs to treat with proper water proofing system. Membrane is used to waterproof the landscape regions. Soil is used to fill in landscaped areas, and there will be a drainage layer to remove water. Materials should be made entirely of recycled polypropylene. In this paper it deals with the different types of water proofing system.

Technical feasibility of using a geotextile waste material as an alternative to agrofilm for mulching in lettuce

ABSTRACT In semiarid regions, water deficit can be a problem affecting agricultural production. Agrofilm mulches can be used to reduce soil water evaporation as well as to control weeds. The SoilTain DW® geotextile blanket, which is a solid waste material generated in water treatment plants, has the potential to be used for mulching in agriculture. The aim of this study was to evaluate the technical feasibility of using this geotextile waste material as an alternative to different agrofilms for mulching in lettuce under the semiarid conditions of the state of Alagoas, Brazil. Four experiments were carried out in 2020–2021, each with four mulching treatments (white and black polyethylene, geotextile blanket, uncovered soil). Soil surface temperature, plant density, weeds and biometric parameters of the lettuce were assessed and evaluated by univariate and multivariate statistical analyses. Significant treatments × experimental period interactions for all lettuce parameters were observed, except for root biomass. Experiment 2 (winter) presented the most favourable environmental conditions for plant development (mild temperatures) and resulted in an average yield of 25.0 Mg ha−1. In Experiment 1 (autumn/winter), high temperatures (47.9°C) under the black polyethylene reduced plant density (96,800 plants ha−1), though leaf length (16.2 cm) and yield (13.1 Mg ha−1) were not significantly affected. The two canonical variables explained 97.7% of the total variation, forming three similarity groups by Tocher method. All mulches effectively controlled the weeds. Application of the geotextile blanket was concluded to be technically feasible, but it was not recommended for use in the summer when temperatures are high.

Trafficability Study of Full-Scale Geosynthetic Portable Road Building System

This study describes the full-scale traffic evaluation of a prototype submersible matting system (SUBMAT) at a test site on the U.S. Army Engineer Research and Development Center’s campus in Vicksburg, MS. The SUBMAT prototype was designed to bridge the gap between high- and low-tide at a beach interface to enable 24-h vehicle offloading operations at an expeditionary watercraft landing site. This unique system is made from common geotextile materials, is filled with indigenous sand using simple commercially available pumps, and creates a robust driving surface. The results of the study showed that the SUBMAT system was able to sustain an accumulation of 1,000 Medium Tactical Vehicle Replacement, 350 Heavy Expanded Mobility Tactical Truck, and over 150 M1A1 main battle tank passes without experiencing any significant damage. The ease of deployment, relatively low cost, and trafficability results could make the SUBMAT a suitable candidate for expedient low-volume roads in austere environments such as stream beds, low-water crossings, recently flooded or flood prone areas, and areas with weak soil.

Behavior of the geotextile reinforced dykes on sand-overlying-clay deposit

An extensive investigation on the performance of large geotextile mat dykes on stiff-over-soft soil deposits is carried out undertaken through numerical simulation in this paper. The large mat is reinforced by geotextiles with a new type of arrangement, i.e. non-uniform geotextile reinforcement. The numerical model is validated against centrifuge test data and other previously testing results, prior to conduct parametric study. It is found that large geotextile reinforced dykes on sand overlying clay fails through a global mechanism that the whole dam sank downwards together. It is found that the thickness of the sand layer, the width of the dyke base, and the shear strength of soft clay are the key influence factors on the stability of the dyke. A design flow chart is then proposed to quantity the performance of the geotextile mat dyke with non-uniform reinforcement, in terms of predicting allowable dyke fill height and the corresponding safety factor, which can be employed to provide refer for its design and construction.

PERFORMANCE ANALYSIS OF DIFFERENT GEOTEXTILE MATERIALS IN EXTENSIVE ROOF GARDEN DESIGNS

Roof garden arrangements, which have emerged in recent years based on environmentally friendly approaches, not only increase urban aesthetics but are also a design approach that contributes to the solution of problems caused by climate change. In this study, the filtration performance of different geotextile materials was investigated based on the extensive roof garden model. The studies related to the research were carried out as an open field pot experiment in Ege University Bayindir Vocational School. Crassula ovata from succulent group plants was used as plant material. 3 filtration materials were tested as filter layers, namely glass fibre, raw cotton, and polypropylene fabric. Various statistical analyses were applied to determine the effectiveness of the filtration materials in extensive roof garden applications. According to statistical significance levels it can be said that the use of polypropylene fabric as filtration material would be more advantageous compared to alternative geotextile materials.

Influence of Geotextile Materials on the Fractal Characteristics of Desiccation Cracking of Soil

In recent years, the irregular cracks formed during the damage evolution of civil engineering materials have been able to be quantitatively described by using fractals. In this study, the fractal characteristics of the desiccation cracking of soil were investigated under different substrate contact and permeability conditions through a natural drying test in the laboratory. Three kinds of base contact conditions of soil, namely, grease, geomembrane, and geotextile, were designed, and two samples for each contact condition, including one parallel sample, were used. The continuous drying experiment was carried out at a constant ambient temperature. The crack morphology under different spacings was analyzed quantitatively using digital image processing technology. The fractal dimensions of three soil substrate contact conditions (grease, geomembranes, and geotextiles) were between 1.238 and 1.93. When the crack network on the soil surface stops developing, the fractal dimensions under the three experimental conditions are 1.88, 1.93 and 1.79, respectively. In the final state of crack development, the crack intensity factor of the sample with grease at the bottom is 2.99% and 4.02% higher than that of the sample with geomembranes and geotextiles at the bottom, respectively. The residual water contents of the samples with bottom contact conditions of grease, geomembrane, and geotextile increase successively, which are 3.12%, 5.76% and 9.71%, respectively. The effects of interface friction and permeability on soil cracking behavior are analyzed, and the evolution characteristics and formation mechanisms of cracks in soil are revealed.

Numerical Study of Geotextile-Reinforced Flexible Pavement Overlying Low-Strength Subgrade

Construction of low-volume flexible pavements on low-strength subgrade poses design, construction, and maintenance challenges. While researchers have generally acknowledged the potential for geosynthetics as reinforcement material, they mainly focused on permanent deformation. Therefore, this paper presents a numerical study of low-volume flexible pavement reinforced with geotextile material under static loading to determine the improvement due to reinforcement based on three criteria: rutting performance, geosynthetic placement location, and base course thickness reduction. Based on the Finite Element Method (FEM), three-dimensional modeling using Abaqus/CAE software was performed. From the study, a significant decrease in rutting of up to 25.2% for the unreinforced pavement system was attained with geotextile reinforcement at base–subgrade and AC–base interfaces. The deflection response behavior of the pavement system is affected by the elastic modulus of the geosynthetic material, placement location, and the number of reinforcement layers. As a result of reinforcement, a base course thickness reduction of up to 30% was achieved without sacrificing the pavement’s structural integrity.

Hydraulic Performance of Geotextile Sand Containers for Coastal Defenses

Laboratory experiments were performed in the wave flume of the Laboratorio di Idraulica e Costruzioni Marittime of the Università Politecnica delle Marche (Ancona, Italy) to study the hydrodynamic performance of coastal protection structures made of a new type of geotextile sand containers (GSCs). Such structures are used as softer and flexible alternatives to traditional hard coastal defenses made of concrete or rubble mound material. The GSC structures can also be used as temporary coastal protections during the winter period. The physical model reproduced two main configurations: in the former one, the GSCs were used as coastal revetments with three different slopes. In the latter one, the GSCs were applied to make detached submerged breakwaters with different submergences and berm widths. The geometric scale of the models was 1:10, and the weight of each GSC in the prototype was 5 t. The geotextile material of the containers and the wave characteristics were reproduced by using the Reynolds and the Froude similarity criteria, respectively. Reflection coefficients and hydraulic stability behaviors for the revetments, as well as transmission coefficients and piling-up amount for breakwaters, were obtained.