Geotextiles are a class of permeable geosynthetic materials. They are fabrics made up of polymers like polypropylene and polyester that act as selective filters in soil. It prevents the mobility of very fine soil particles that could go into drainage systems or weaken the integrity of soil. Geotextiles are superb in drainage, separation of dissimilar soil layers, and erosion control. The wide range of applications makes them of great utility in civil engineering applications. Geotextiles come in two basic forms: woven geotextiles that are similar to cloth, and nonwoven geotextiles that have a felt-like texture.
The need for geotextiles was borne out of the need for optimal substitutes for granular soil filters in the 1950s. It had a large range of applications. R.J. Barrett pioneered the work on geotextiles when he started working on the uses of geotextiles for shoreline protection. Permeability with simultaneous retention of soil particles was quite a challenge for design.
Extensive research was eventually done on geotextiles. Based on that work, a higher variety of geotextile designs were developed. It met the specific requirements of different applications. From filtration and drainage on streets and railways to erosion control and slope stability, this new variety of geotextiles provided customized solutions to the varied requirements of the engineers. The numerous advantages that geotextiles possessed were further extended by the advent of newer manufacturing techniques like needle-punching and heat-bonding.
What makes geotextiles stand out is their ability to interact with the soil through five key processes: separation, drainage, filtration, reinforcement, and protection:
Separation: Geotextiles work as barriers between dissimilar soil materials, preserving the individual characteristics of those materials. This is, for example, noted in the road construction where the geotextiles separate the fine subgrade aggregate from the coarse aggregates of the base layer, leaving the drainage capacity of the road intact.
Drainage: Bidirectional water flow, supplemented by the restriction of movement of the fine soil particles, are ensured by the geotextiles. Lateral drainage flow and the hindrance to the capillary rise of ground water make the geotextiles useful around the houses, roads, and curbs.
Filtration: Water filters through geotextiles in both directions, and nothing will pass through the filters. They are laterally drainable but they are good against capillary rise. Geotextiles are installed horizontally and vertically. Applications around houses, roads, and curbs are the best.
Reinforcement: Geotextiles are designed for tackling critical factors such as preventing movement, carrying loads, and changing the bearing failure planes. Weaker soils can be reinforced with geotextiles to allow the construction of steep embankments without hindrances.
Protection: Geotextiles in several layers are used to protect the integrity of embankments by reducing erosion of fine materials. This property makes geotextiles useful in rock beaching, mattress structures, and underwater deployment. In addition, some of the geotextiles can be infused with asphaltic emulsions to make them impermeable, suitable for moisture barriers in pavement repairs.
Based on their manufacturing process, geotextiles are categorized into three primary types: woven, non-woven, and knitted.
Woven geotextiles were the first class of geotextiles. They were developed through adapting weaving techniques commonly used in textile production. Woven geotextiles have a characteristic appearance with two sets of parallel threads. In this structure, the warp threads run longitudinally and the weft threads perpendicularly. Woven geotextiles are manufactured from polypropylene in various forms, like extruded tapes, monofilament yarns, or multifilament yarns.
In contrast to woven geotextiles, non-woven geotextiles are created by bonding short staple fibers or continuous filament yarns. They can be bonded thermally, chemically, mechanically, or by combining these techniques. The kind of fiber (staple or continuous) has negligible impact on the properties of the non-woven geotextile. Thermally bonded nonwovens put forth a wider range of opening sizes and have a thickness range of 0.5 to 1 millimeter. Conversely, chemically bonded nonwovens are generally thicker, around 3 millimeters. Mechanically bonded varieties require a larger quantity of polymer filaments and thus tend to be thicker (2–5 millimeters) and heavier.
As the name suggests, knitted geotextiles are manufactured by knitting which involves interlocking a series of yarn loops together. There is only a finite supply of knitted geotextiles that are commercially available. As a consequence, they often combine knitting with another manufacturing method, like weaving.
Conventional methods of reinforcement fail to provide the numerous benefits geotextiles possess. These advantages stem from their ability to interact with soil in various ways.
Improved soil stability: Geotextiles boost the stability of the soil by distributing structural loads across a wider area. Consequently, the risk of settlement and failure is diminished by a wide margin. Geotextiles can also prevent differential settlement as they curb the undesirable mixing of different soil layers.
Cost-effective solutions: Geotextiles are a prevalent choice in civil engineering projects owing to their cost-effectiveness. They are more adept at reducing stress on the pocket and the soil than gravel and concrete. The need for excavation is also eliminated with the help of geotextiles, leading to time and cost savings.
Ease of installation: Workers and engineers alike do not experience complicated installation processes as geotextiles require minimal equipment to set up. It is possible to deploy them in various weather conditions and uneven terrain, reducing installation time and cost.
Environmentally friendly: Geotextiles are composed of synthetic or natural biodegradable fibers that lower the environmental impact. They also improve the soil quality, which positively influences the ecosystem.
Versatility: Gravel and concrete can be combined with geotextiles to improve structural strength and stability. They are suitable for drainage, filtration, reinforcement, erosion control, and soil stabilization applications.
Reinforcement and load distribution: The tensile and shear strengths of the soil get multiplied upon the installation of geotextiles. This attribute stems from a geotextile’s ability to help the soil function as a uniformly distributed reinforcement layer. The applied loads are effectively dispersed, thereby tapering any cases of deformation.
Isolation and leakage prevention: For construction projects, geotextiles keep different soil layers from mixing and leaking into each other. A characteristic is often seen in road construction where geotextiles prevent the base layer from mixing and being contaminated by the superimposed materials.
Drainage Properties: Certain geotextiles facilitate the rapid removal of moisture from the soil as they possess excellent drainage capabilities. This addresses any issues related to moisture accumulation and infiltration. Optimal drainage helps with soil stability and reduces hydrological stress.
Chemical corrosion resistance: Geotextiles possess excellent resistance to chemical corrosion. This does not just guarantee long-term stability but also helps in their deployment in multiple situations.They can be deployed in varying engineered environments like chemical plants, landfills, and agricultural sites.
Convenient construction and maintenance: Easy customization and cutting properties of geotextiles help engineers devise specific solutions for specific challenges. Their ease of installation and handling make them a valuable asset. Soil, concrete, and rock can also be integrated with geotextiles to further strengthen the structure.
Geotextiles come with countless benefits for engineering applications. However, it is important to be mindful of the areas where they fall short:
Limited load capacity: Compared to concrete and gravel, geotextiles possess a limited capacity to bear loads. As a consequence, they are not suitable for high-load support applications.
Durability concerns: Exposure to UV radiation, oxidation from heat and light, hydrolysis, and chemical attacks are a few factors that can cause degradation in geotextiles. The long-term strength can be adversely affected by these factors.
Environmental impact: The hydrocarbons, petrochemicals and fossil fuels used to manufacture synthetic geotextiles increase the percentage of greenhouse gas emissions. These non-biodegradable materials also harm soil, water, air, and the ecological balance. It is recommended that research be conducted to explore and reduce the environmental impact of synthetic geotextiles.
Limited Lifespan: Geotextiles have a shorter lifespan when compared to more sturdy materials. Their efficiency in water control and soil conservation hinges on their ability to perform at their peak throughout their lifespan.
A project to modernize a causeway in Titusville, FL, aimed to replace an aging bridge linking the city to the NASA Kennedy Space Center. The construction required building approaches on both sides of the bridge while keeping the road open to ensure access for NASA employees, researchers, public visitors, and dignitaries.
The challenge was to maintain uninterrupted access to the Space Center during construction. This required a phased construction approach while working in a sensitive marine environment prone to storms. The project needed a flexible, temporary retaining wall system to support the bridge approach while accommodating both traffic and environmental factors.
A temporary reinforced soil wall was chosen, incorporating StrataGridTM geogrids wrapped in nonwoven geotextile (ST 160). The geotextile served as a protective face wrap for the geogrids, ensuring stability and erosion control. The system provided a robust and aesthetically pleasing structure while allowing rapid construction and flexibility to work around obstacles, including a large-diameter pipe.
● Cost-effective: Utilized locally sourced materials to minimize expenses.
● Robust design: Engineered to support full traffic loads expected over the bridge approach.
● Flexibility: Designed for easy installation and removal, accommodating large-diameter pipes within its structure.
● Aesthetic appeal: The façade was designed to be visually appealing due to high-profile traffic.
● Rapid construction: Quick assembly minimized downtime, crucial in the storm-prone South Florida environment.
Strata Global’s reinforced soil wall solution effectively ensured continued access to NASA Kennedy Space Center during critical infrastructure upgrades. This project highlights Strata’s ability to deliver innovative engineering solutions tailored to complex environmental and logistical challenges.
Civil engineering projects have greatly benefited from the use of geotextiles in recent years. These fabrics are designed to interact with soil environments in multiple ways. They excel in five key functions: separation, filtration, reinforcement, protection, and drainage. Functioning as barriers between dissimilar soils, they prevent fine soil particles from migrating and improve the soil for steeper embankment construction. Geotextiles also protect embankments from erosion and act as effective drainage filters. Considering the many advantages they offer, geotextiles are a step towards the future. They improve soil stability, promote drainage, and curb erosion, all while being a cost-effective solution.
Strata Global offers a complete range of geotextile products designed for civil engineering projects. Our product StrataTex HSR™, a woven geotextile of unsurpassed strength, is specifically designed to reinforce soil structures.This product exhibits high tensile strength and modulus, making it the product of choice when used in reinforced soil applications like retaining walls, slope stabilization, and embankments. To add to it, it is a sturdy product with a proven ability to perform in a wide variety of soil types and environments.
Contact us today if you wish to know more about our range of geotextile products. Our team of experts is ever-ready to answer your queries and help you save time, and find the most effective solutions for your civil engineering needs.
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Director, President – Glen Raven Technical Fabrics
Strata/Glen Raven tenure: 10 years/28 years
Total industry experience: 35 years
MBA – Wake Forest University
Directs the strategic direction of Glen Raven’s automotive, protective apparel, military, geogrid, outdoor and logistic businesses.
Director, General Manager, Strata Inc.
Strata/Strata Inc. tenure: 3 years/14 years
Total industry experience: 25 years
MBA – Georgia State University
Led the integration of Strata Inc. business operations into the headquarters of GRTF and transition from USA based to India based manufacturing.
Director
Strata tenure: 17 years
Total industry experience: 47 years
CA – ICA
Played a key role in the establishment of Strata’s India operations. Provides vision for product innovation and leveraging new technology trends.
Global Technical Sales Director
Strata tenure: 7 years
Total industry experience: 32 years
Civil & Geotechnical Engineer (First class)
Provides highly technical and innovative civil engineering solutions in India and around the world. Responsible for the design and execution of large-scale geotechnical projects around the world including Australia, Asia, Europe, Africa, Middle East, and South America.
CTO – Chief Technology Officer
Strata tenure: 9 years
Total industry experience: 48 years
BTech (Hons), MTech (Civil) Both IIT Bombay, DMS (Bombay University), FIE, FIGS, Chartered Engineer
Streamlines the designs of Geosynthetics and has brought innovation in geogrid and geocell design application.
COO – Projects and Sales
Strata tenure: 13 years
Total industry experience: 24 years
MBA – University of Gujarat
Leads the monetization of products and solutions while ensuring highest execution quality and project profitability.
COO – Technical Textiles
Strata tenure: 13 years
Total industry experience: 33 years
BE (Mechanical) – Nagpur University
Drives excellence in process design, product features and cost effectiveness in production.
CFO – Chief Financial Officer
Strata tenure: 8 years
Total industry experience: 35 years
CA – ICA, ICWA – ICWAI
Leads the finance, accounting, taxation, commercial, legal and IT functions and assisting on all strategic and operational matters.
CDO – Chief Development Officer
Strata tenure: 10 years
Total industry experience: 13 years
MBA – ISB, Hyderabad
Leads diversification of the product portfolio, monetizing the new products and ensuring successful sustained financial growth of the company top line.
CEO – Chief Executive Officer
Strata tenure: 14 years
Total industry experience: 42 years
B Tech (Chemical) – IIT Delhi
Leads day-to-day business operations of the company with focus on capacity expansion, product and process improvement.
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