What are Geotextiles: Types, Application, Advantages & Disadvantages
Geotextiles are artificial or organic textile materials that help with soil stability, drainage, filtration, and erosion management. Due to their adaptability and efficiency in improving soil quality, they have become necessary in many civil engineering projects. Geotextiles possess a variety of forms, including woven, non-woven, and knitted, each having its own special qualities and attributes. They are used in a wide variety of projects, including building retaining walls, trench reinforcement, preventing erosion, and roads.
Types of Geotextiles
Polymers like polypropylene and polyester are used to make geotextiles. According to the method of production, they are categorised into three categories:
Woven Fabric: The most prevalent geotextiles are made of woven fabric, and the technique used in their production is comparable to that used in clothing materials. Parallel threads or two sets of threads are used to create this sort of geotextile.
Nonwoven Fabric: Short or long-staple fibres are used for making nonwoven geotextiles. They involve thermal, chemical, mechanical, or a mix of various approaches.
Knitted Fabric: A succession of yarn rounds are interlocked to create knitted geotextiles. These geosynthetics are produced by fusing the weaving strategy with other weaving-related methodologies.
Application of Geotextiles
Following are the major applications of Geotextiles:
- Road Work: Geotextiles are often used in the building of roads. Increasing tensile strength fortifies the soil. Geo-textile fabrics must maintain flexibility without losing their unique properties since they are utilised as a rapid water level in roadbeds.
- Railway Works: Where the ground is unstable, soil and subsoil are separated using woven or non-woven fabrics without preventing groundwater rotation. The material won’t stray from the edge owing to impacts and tremors from moving trains if the individual layers are covered in fabric.
- Agriculture: It is used to control sludge. Non-woven fabrics are utilised and folded by overlaying to confine a mass of pipe or grit in order to improve muddy roads and trails used by cattle or light traffic.
- Drainage: An economically viable alternative to conventional systems is the use of geotextiles for soil filtration and more or less uniform-sized granular materials for water transportation. Earth dams, roads and highways, reservoirs, walls of retention, deep drainage ditches, and agricultural drainage all use geofabrics to filter the water.
- Canal, river, and coastal works: Riverbank erosion brought on by currents or lapping is protected with geotextiles. They function as a filter when utilised in conjunction with organic or synthetic encapsulation.
Functions of Geotextiles
Following are the Functions of Geotextiles:
In order to preserve or enhance the functionality of two different materials, porous geotextile layers are positioned between the two different or dissimilar materials.
Separation is employed in transportation-related applications to stop the mixing of two neighbouring soil layers.
The fine sub-grade soil and the fine aggregate of the base course are separated by the geotextile layer. Additionally, the geotextiles have maintained drainage and aggregate strength. For all kinds of roads, various foundation types, and the ground floors of buildings, geotextile separators are utilised. Geofabrics also prevent the structure from failing too soon, and separators stop the pumping effect caused by dynamic loads while allowing water to pass while holding the soil particles in place.
The equilibrium textile layer to the soil is filtration, which permits correct water flow with less soil loss across the geotextile plane. The filtering material can be either nonwoven or woven, allowing water to pass through while trapping soil particles. The main characteristics of geotextile are infiltration action, permeability, and porosity, and geotextile bending application can be used for both vertical and horizontal drains. Additionally, categorised aggregate replacement uses this warping application.
The insertion of a geotextile into the soil led to a synergistic enhancement in the overall system strength, which was principally established through the following three mechanisms:
- Interfacial friction between the geotextile and the soil or aggregate provides lateral constraint.
- Wheel load supports in the form of membranes.
- Potential failure plane of the bearing surface driving the development of an alternative surface with better shear strength.
The tensile strength of the geosynthetic material used in the way described above significantly increases the structural stability of the soil. Steel reinforcement is used to strengthen concrete since it is weak in tension. Similar to steel reinforcement, geosynthetic material works by providing strength to keep the soil in place. Roads can be created over extremely brittle soils with the use of geogrid or geotextiles, which also enable the construction of steeper embankments.
This configuration is comparable to steel and reinforced concrete. Steel reinforcement is used to strengthen concrete since it is weak in tension. Similar to steel reinforcement, geosynthetic materials work by giving strength to aid in stabilising the soil. The reinforcement enables the use of geotextiles and geogrids, enabling the construction of steeper embankments and the paving over of porous soils for roads and embankments.
- Sealing Function
When the nonwoven type geotextile gets coated with asphalt or polymeric mix rendering, it serves this purpose since it is comparatively impermeable to both planes, such as in-plane and cross-plane flow. The synthetic geotextile membranes are affixed to the pavement’s current surface.
Asphalt is absorbed by the geotextile, which transforms into a waterproofing membrane. As a result, the vertical flow of water into the foundation of the pavement is minimised.
Advantages of Geotextiles
- They are lightweight, making them simple to handle and set down.
- Real costs for labour and transportation are lower.
- Knitted materials have great strength for cutting.
Disadvantages of Geotextiles
- Geotextile installation is essential and calls for specialised professionals.
- The low soil temperature can postpone seed germination.
- Maximum flow rates exist.
- The base is not appropriate for places that are crowded.