You’ve probably heard of many kinds of fabrics, but geotextiles? In this article, we’ll discover this distinctive form of textile and see what it is specifically made to do.
Geotextile Fabrics
When we talk about textiles, we’re talking about fabrics. That’s what textiles are: fabrics and clothes made from weave fibers. Our lives are full of textiles. We wear them as clothing, use them for bedding, and wrap ourselves in them to stay warm, decorate our houses with them and use them to grow corn. Wait, what?
There are more uses to textiles than meet the eye. Textiles are also a big part of agriculture and ecosystem management. Specifically, we use permeable fabrics called geotextiles to help control erosion and maintain soil stability. It’s a textile worn not by us but by the earth. Turns out, Mother Nature likes a good textile as much as we do.
Use of Geotextile Fabrics
Geotextiles are fabrics applied to the soil, but why? These aren’t your average picnic blankets, after all. A geotextile is designed with the specific intent of improving or managing the soil, generally for conservation or agricultural purposes. There’s actually an ancient tradition here; ancient Egyptians mixed natural plant fibers into the soil in order to strengthen it. Since the 1950s, we’ve used synthetic polymers to create modern geotextiles.
Types of GeotextilesLet’s think about some of the situations in which geotextiles would be needed. Imagine being a rancher who is raising cattle. When you introduce livestock to an ecosystem, the hooves can trample and kill off the grass. Without plants, there are no roots to hold the soil together, and the land begins to erode. Geotextiles help hold the ground together, acting almost like synthetic roots while providing a stable base for new plant life to grow on. Geotextiles are used on ranches and farms, as well as eroding river systems, hillsides with homes and businesses, or any other place where soils need a little stabilization.
Geotextiles are made for practical reasons, so there are different types that are designed for different purposes. In general, these can be sorted into two main categories.
Woven Geotextiles
Woven geotextiles are made with synthetic polymers that are woven together, the way that most fabrics are. These take longer to make, but also have a high tensile strength and load capacity. Basically, woven geotextiles are best when you need something very sturdy and durable.
Because of this, woven geotextiles are used for support and stabilization. For example, many roads and parking lots are built on top of a woven geotextile. The fabric holds the earth in place, preventing shifting or movement and creating a stable base for the construction on top of it. Woven textiles are also used to prop up shorelines or beaches that are at risk of collapsing or washing away, as well as to protect grounds from wind damage.
Overall, woven textiles are utilized for their strength. However, this high tensile strength makes the geotextiles relatively impermeable. This means that they will hold, rather than absorb or filter, water. So, if filtration is a big priority for your project, you may consider using something else.
Non-Woven Geotextiles
This is where non-woven geotextiles come into play. Non-woven geotextiles, which have the texture of felt, are often quicker and cheaper to create but also have shorter lifespans and do nothing to help reinforce or stabilize the soil. What they’re great at, however, is altering water. These fabrics absorb water and distribute it across a horizontal plane, reducing the effects of water damage. For this reason, non-woven geotextiles are very often used for erosion control.
Because of this wide variety, they can be applied in at least five different ways:
- Separation
Geotextiles will prevent two soil layers of different particle sizes from mixing with each other, as is illustrated the image below.
- Drainage
Geotextiles will efficiently collect superfluous water from structures, such as rainwater or surplus water, from the soil and discharge it.
- Filtration
Geotextiles are an ideal interface for reverse filtration in the soil adjacent to the geotextile. In all soils water allows fine particles to be moved. Part of these particles will be halted at the filter interface; some will be halted within the filter itself while the rest will pass into the drain. The complex needle-punched structure of the geotextile enables the retention of fine particles without reducing the permeability of the drain.
- Reinforcement
Heavy geotextiles can be used to reinforce earth structures by means of fill materials. Thanks to their high soil fabric friction coefficient and high tensile strength, they are an ideal reinforcement solution.
- Protection
Geotextiles are an ideal protection from erosion of earth embankments by wave action, currents or repeated drawdown. A layer of geotextiles can be placed so as to prevent leaching of fine material. They can be used for rock beaching or as mattress structures. They can even easily be placed under water.
Geotextile Application by Function:
This chart determines which type we have been used in our last projects:
Function | Type of Geotextile Recommended | Fabric Weight Recommended | Time |
Drainage | Nonwoven (Light or Medium Weight) | 3.1 to 8 oz. Fabrics | 4:6 Days |