Why use geogrids, and how to choose the right one?
Modern infrastructure has become increasingly sophisticated as engineers aim to balance the demands of a rising population with the global need for environmentally sound structures. These structures need systems that can deliver multiple functions throughout a long lifecycle without sacrificing quality. Geogrids, made from durable polymers, are perfectly suited for this type of high-demand construction. These geosynthetic materials feature interconnected, parallel sets of high-tensile ribs. The apertures between the ribs are large enough to allow the surrounding soil, stone, or other geotechnical materials to pass through and interlock. Geogrids are widely used in geotechnical projects for applications such as:
Load distribution and improved structural stability
Geogrids offer high tensile strength, allowing them to spread loads across a wider area within the soil, which enhances structural stability across different soil types. Geogrids support the construction of taller retaining walls and foundations on weak soils, helping to reduce the risk of soil erosion and slope instability. Retaining walls use longer geogrids, which increase the mass of the structure, while the geogrids tie everything together as a unified unit.
Soil erosion prevention
Wind, rain, or traffic causes soil erosion. By confining and reinforcing soil layers, geogrids act as a barrier to such soil erosion. This property is utilized in erosion control for slope stabilization projects, where geogrids curb soil movement and potential failure.
What are the applications of geogrids?
Retaining wall construction
Geogrids, when placed within the backfill soil of retaining walls, provide excellent reinforcement and improve load distribution. This adds stability to the walls and allows construction of taller and more complex structures without compromising the quality of the soil.
Soil stabilization
Geogrids have different strengths in improving the structural integrity of sloping ground. Uniaxial geogrids provide strength in machine direction whereas the biaxial geogrids provide strength in both machine and cross machine direction. Uniaxial geogrids are essential for reinforcing structures with a vertical load, such as earth retaining walls, while biaxial geogrids are ideal for evenly distributing loads in applications like road construction and working platforms.
Pavement construction
Geogrids are used to reinforce pavement bases, with the use of thinner base layers while achieving adequate stiffness. Construction costs and time are saved with the help of geogrids while ensuring the longevity of the structures at the same time.
Factors to consider when choosing a geogrid
Selecting the optimal geogrid for a project requires diligent planning and consideration of all key factors. Geogrids that exhibit insufficient strength or unsuitable material properties for specific load requirements can compromise the structural integrity of the reinforced soil mass. Poor tensile strength can result in retaining wall failure, foundation settlement exceeding tolerable limits, or pavement cracking. Conversely, a well-chosen geogrid system assists in the sustained reinforcement of the soil structure and poses no qualms about quality of the materials when they interact with the soil. A lower-grade geogrid may seem cost-effective initially but is likely to lack the long-term durability and mechanical properties required for a reliable project. This could invariably lead to added costs in repair or replacement needs. Finally, selecting a geogrid with a focus on sustainability contributes to a more ecologically sound project. An environment friendly option could involve considering geogrids created from recycled materials or those with a lower environmental footprint during production
Strength and durability
The geogrid should possess high tensile strength that can handle the anticipated loads within the reinforced soil structure. A strong geogrid is more effective in applications like retaining walls, where the geogrid needs to restrain and stabilize soil mass without potential failures. Durability is just as important, as the geogrid faces harsh environmental conditions throughout the project’s lifespan. This involves conditions like exposure to sunlight, rainfall and chemical degradation in the soil.
Compatibility with soil types
A geogrid that is compatible effectively with the surrounding soil is a suitable choice for reinforcement operations. Different soil types have varying properties, such as grain size and drainage properties. The ideal geogrid should allow for proper water infiltration and sufficient friction to prevent soil movement within the reinforced area.
Ease of installation
Efficient installation leads to reduced project costs and completion of deadlines. Factors like roll width, weight, and the ability to unroll and lay flat can impact installation speed. Geogrids with features that reduce on-site cutting and require less manpower for deployment are generally preferred by engineers.
Elongation and stress-strain values
Elongation is defined by the amount a material stretches when put under stress. In geogrids, low elongation is preferable as it maintains the integrity of the reinforced soil mass. Geogrids that elongate excessively under load do not confine the soil adequately.
Project requirements
The specific deployment of the geogrid influences the selection process. To illustrate, uniaxial geogrids which possess high tensile strength in one direction are suitable for walls and slopes, while biaxial geogrids (offer strength in both directions) are plied in roads and pavements.
Resistance to chemicals
The geogrid should exhibit resistance to chemical degradation from the surrounding soil and other contaminants. Chances of premature failure are negated and a sustained performance is ensured.
Environmental impact
The focus on environmentally sustainable practices has been increasing over the years. Some geogrids are manufactured from recycled materials, and some manufacturers offer production processes with low ecological impact. Considering these factors contributes to an environmentally friendly project.
What makes Strata Geosystems’ geogrids the best?
Strata Geosystems set the standard in geogrid technology with their innovative products, StrataGrid uniaxial (SGU) geogrids and the series of StrataGrid biaxial (SGB) geogrid. These geogrids are made with high-performance polyester yarns, offering a high tensile strength at lower elongations and industry-leading performance. They are coated with a saturation coating for added durability. This engineered excellence makes them ideal for soil reinforcement and pavement construction applications. Let’s delve into the key features and benefits of these geogrids:
Superior tensile strength
StrataGrid uniaxial (SGU) offers strengths of up to 800 kN, ensuring stability under heavy loads and enhancing soil structure reinforcement. The StrataGrid biaxial (SGB) geogrid also provides exceptional strength, ranging from 20kN/m to 150kN/m, offering superior reinforcement for pavement base layers.
Longevity and sustainability
With a design life of up to 100 years, StrataGrid ensures long-term stability and erosion control, providing a sustainable solution for infrastructure projects. The StrataGrid biaxial (SGB) geogrid also contributes to environmental sustainability by reducing pavement crust thickness and decreasing the carbon footprint associated with construction.
Efficient functionality
StrataGrid uniaxial (SGU) is engineered specifically to improve the modulus values of pavement base layers, optimizing the performance and longevity of infrastructure projects. The StrataGrid biaxial (SGB) geogrid enhances the structural integrity and strength of the pavement, resulting in increased durability and a longer lifespan.
Easy installation
The SGB grid, with its 5 m width, minimizes overlaps, reducing wastage and optimizing pavement costs. This grid series is designed for enhanced pavement strength, providing low overlaps during installation and minimizing material wastage.
Impressive widths
StrataGrid, a product from Strata Geosystems, offers impressive widths of up to 5.7 m (~18 feet), reducing installation time and costs. This width is also available in the StrataGrid biaxial (SGB) geogrid, which is specifically designed for pavement construction and soil reinforcement, particularly in highway embankments.
Industry leading performance
StrataGrid showcases outstanding stress-strain values with minimal elongation, providing reliable and long-lasting soil reinforcement. The StrataGrid biaxial (SGB) geogrid surpasses conventional solutions in the market with its exceptional tensile resistance at lower elongations, ensuring durability and longevity in flexible pavements.
Here are real-life examples of Strata’s expertise in geogrid solutions. Two case studies showcase the geogrid’s adaptability and effectiveness in building reinforced soil walls in different locations.
StrataGrid™ and StrataBlock™ system used in reinforced soil wall project in Gujarat, India
The National Highways Authority of India’s project on NH-8 serves as a prime example of StrataGrid’s prevalence in the field of large-scale reinforced soil wall construction. The primary challenge was the erratic soil conditions and seepage water at each location, as the soil investigation report indicated weak soil prone to excessive settlement. To address these challenges, a reinforced soil wall system was chosen as the optimal solution based on the soil conditions. StrataGrid and StrataBlock units were utilized for the construction of the reinforced soil wall due to their proven performance and easy installation procedure. The economic and time-saving benefits of reinforced soil walls, compared to traditional methods, played a key role in NHAI’s decision-making process. StrataGrid’s ease of installation and compatibility with locally available soil contributed to the project’s fulfillment. The project’s success, using StrataGrid with locally available non-plastic soil, showcased the geogrid’s versatility and adaptability across different geographical locations. In essence, the project is a testament to StrataGrid’s dominance in reinforced soil wall construction. Its successful application in a large-scale project, combined with Strata’s technical expertise, positions StrataGrid at the forefront for clients seeking high-performance geogrid solutions.
StrataGrid™ used in the construction of retaining walls at Al Qatif, Saudi Arabia
StrataGrid’s effectiveness in expediting construction of block fascia retaining walls in adverse soil conditions is exemplified by the Ministry of Municipal and Rural Affairs’ project in Saudi Arabia’s Eastern Province. The project’s challenging 45-day completion deadline was met thanks to the ease of StrataGrid’s installation. The installation process was made easier by features such as roll properties that minimized on-site cutting. This was further streamlined by the prefabricated, interlocking StrataBlock system. Its built-in slope and self-alignment capabilities eliminated the need for slow cast-in-place concrete work. StrataGrid’s ability to retain the soil mass and improve load distribution, along with its compatibility with locally available non-plastic soils, tackled the issues related to weak foundations. To add to it, the inherent aesthetics of the precast StrataBlock system fulfilled the project’s requirement with a simplicity and sophistication that is synonymous with Strata. The project had a minimal carbon footprint because the StrataBlock system eliminated need for conventional concrete. The efficiency and expertise demonstrated by Strata’s engineers is evident in this case, as they delivered a fast, efficient, and tailored solution.
Strata’s team of engineers provides technical expertise and support for turnkey projects, ensuring top-quality execution and maximum project profitability. We provide cost efficient, durable, environmentally friendly, sustainable and timely solutions for all geotechnical projects. Contact our team of experts.