In simple terms, soil reinforcement is a technique used to improve the stiffness and strength of soil using geo-engineering methods. A long time ago, natural fibre was used to reinforce the soil. This old technique did not have a high yield and required a lot of time for the soil to recover.
In geotechnical engineering, soil is restored and reinforced with the distribution of minerals and soil nutrients. Soil reinforcement is necessary in lands where chances of erosion are high. It is particularly useful in areas with soft soil as it cannot provide adequate support to any construction or building. This type of soil is also highly susceptible to various environmental and natural factors such as high compressibility, poor shear strength, temperature changes, etc.
In soil reinforcement, different engineering techniques are used to enhance the soil strength. One product that is available is geogrids.
“The MacGrid geogrids are most commonly used in soil reinforcement as they are engineered to be extremely durable and resistant. There are 3 different types of Geogrids available, all of which you can find more about at https://www.maccaferri.com/my/products/geogrid-macgrid/”
Geotextiles are another popular option as they are cost-effective, more profitable and highly adaptable. This serves to maximise the reproducibility of soil and thickens the soil volume for increased strength.
A geotextile is a woven permeable fabric. In geotechnical and bioengineering, it is used for separation, filtration, protection, reinforcement and drainage of soil. It allows a two-way exchange: across the fibre and within the fibre. With over 80 applications, geotextiles are manufactured with polymer, propylene, or high density polyethylene depending on the soil requirements. Generally, there are three types of manufacturing methods for geotextiles: pressing, felting and weaving.
How is Soil Reinforcement Done?
Soil reinforcement is performed by placing tensile elements in the soil to enhance its natural stability and strength. This is achieved by bringing reinforcement elements in contact with surfaces in the aggregate and sub-base of soil mass. When pressure on the soil mass causes a strain on the reinforcements, it creates a tensile load which can resist soil movement and provide additional support for increased strength. This way, a soil-reinforcement system is created which provides greater shear strength than the soil mass alone.
Challenges in Soil Reinforcement
Soil reinforcement plans are always customized according to the soil texture and its load bearing capacity. Due to a wide variety of soil and load variants, bioengineers experience a number of challenges during soil reinforcement. These include:
For Embankments on Weaker Foundations
For embankments on weaker foundations such as airports near sandy ground, the biggest challenge is to reinforce the soil and stabilise it.
For Steeping Slopes
Layers of geotextile are placed strategically on the land to steepen soil slopes. The purpose is to increase the tensile strength of the soil for minimal sliding or rotation.
For Retaining Walls
Different kinds of wall applications are blended with geotextiles such as on-site fills to reinforce soil supporting walls. Geotextile provides an alternative to traditional cast-in-place concrete structures for retaining walls.
Subgrade Stabilizing
The tensile strength of soft and organic soil is low. The initial cost of traditional land filling can be up to 50% higher than the cost of soil reinforcement with geotextiles. Geotextiles can be used to distribute the load uniformly within the soil and minimize the displacement of small soil particles. Hence, geotextiles are a low cost alternative to traditional sub-grade displacement, excavation followed by replacement and chemical soil stabilizing techniques.
For Reinforcing the Base Course
The load bearing capacity of soft soil can be improved by increasing the tensile strength of granular base course material. Geotextile increases the tensile strength of soil by increasing its load bearing capacity at the granular base structure. A grid structure is commonly used for reinforcing the granular base course.
For Closing a Soft Site
Geotextiles are a cost-effective method of reinforcing soft soils in areas such as lagoons, sludge ponds, etc. Geotextiles can strengthen soft soil by providing high tensile support and anti-deformation capability to support building structures and improve the quality of soil body.
For more information, please e-mail contactemilyroberts@gmail.com.