It will be apprpiate to identify the primary functions of geosynthetic materials for their specific applications
Major Applications :
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Separation
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Filtration
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Drainage
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Reinforcement
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Erosion Control
Separation
10 pounds of a stone place on 10 pounds of mud results in 20 pounds of mud
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It acts to separate two layers of soil that have different particle size distributions.
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Separators also help to prevent fine-grained subgrade soils from being pumped into permeable granular road bases
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Geotextiles are used to prevent road base materials from penetrating into underlying soft subgrade soils, thus maintaining design thickness and integrity of the crust.
Filtration
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It acts similar to a sand filter by allowing water to move through the soil while retaining all upstream soil particles.
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Geotextiles are used to prevent soils from migrating into drainage aggregate or pipes while maintaining flow through the system.
Drainage
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It acts as a drain to carry fluid flows through less permeable soils.
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Geotextiles are used to dissipate pore water pressures at the base of roadway embankments.
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For higher flows, geocomposite drains have been developed. These materials have been used as pavement edge drains, slope interceptor drains, and abutment and retaining wall drains.
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Prefabricated vertical drains (PVDs) have been used to accelerate consolidation of soft cohesive foundation soils below embankments and preload fills.
Reinforcement
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It acts as a reinforcement element within a soil mass or in combination with the soil to produce a composite that has improved strength and deformation properties over the unreinforced soil.
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Geotextiles and geogrids are used to add tensile strength to a soil mass in order to create vertical or near-vertical changes in grade (reinforced soil walls).
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Reinforcement enables embankments to be constructed over very soft foundations and to build embankment side slopes at steeper angles than would be possible with unreinforced soil.
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Geosynthetics (usually geogrids) have also been used to bridge over voids that may develop below load bearing granular layers (roads and railways) or below cover systems in landfill applications.
