EROSION AND SEDIMENT CONTROL

We offer a wide range of geotextiles that have been demonstrated to be effective for ground protection from erosion. The primary function of geotextiles is to minimize surficial soil particle movement via surface water flow. These geotextiles aid in minimizing the movement of soil particles on areas, such as soil slopes and embankments, by behaving as a retaining protection layer when placed against a surface of soil.

The monofilament woven geotextiles are designed to offer a combination of high strength and excellent hydraulic characteristics. They prevent soil migration in areas with lightweight soils such as seawalls, bulkheads and shoreline protection, or under bedding stone in highway rip-rap applications. Geotextile bags/tubes composed of  geotextiles offer high strength, excellent hydraulic properties due to its high apparent opening size and clog resistance. They perform efficiently in in hydraulic, coastal, offshore engineering and river protection applications. Geotextile bags and tubes have been proven to be an eco-friendly, construction-friendly, and cost-effective alternative to conventional protection methods.

ASPHAULT OVERLAY PAVEMENT

The non-woven needle-punched geotextiles, GC130 and GC140, are utilized as paving fabrics to increase the flexibility of a particular roadway structure. Paving fabrics are bonded to the road surface and saturated with bitumen to effectively seal the existing pavement and waterproof the overlay. The primary function of asphalt overlay paving geotextiles is to act as a stress relieving membrane between several layers of pavement. As the geotextile is bonded with saturated asphalt cement to existing asphalt, the fabric placement reduces reflective cracking and deterioration that could potentially lead to a roadway failure.

Pavement deterioration is caused by shear and tensile stresses induced by traffic loads, change in pavement temperature, shrink/swell soils, existing cracks, and movements of the underlying pavement structure. Proven benefits of using these geotextiles in concrete pavement overlays includes:

• Waterproofing of the lower layers, thereby, maintaining higher material strengths
• Reducing reflective cracking in the overlay by acting as a stress absorbing membrane interlayer.
• Increase in structural stability by providing for more stable subgrade moisture contents.
• Increase roadway lifespan and decrease maintenance intervals
• Reduction of material/demolition cost and decreasing the total amount of construction time.

ENVIRONMENTAL – LANDFILL
Landfills are highly complex, well-engineered series of cells in or above the ground. Each cell is lined with an advanced liner system which prevents trash migration and contamination of groundwater. Geonet, Geocomposite and Geotextile are best technical and financial drainage option for landfill Cell and Cap.
SKAPS products offer safer solution to improve the environment as well as increase the capacity of the landfill.

The Geocomposite offer following functions:

• Separation
• Filtration
• Drainage
• Containment

Why Use These Geocomposites in Landfill?

• Offer high drainage capacity under any slope and/or load.
• Great resistance to crushing
• Excellent behavior in terms of creep or fatigue, long term drainage
• Offer greater durability when confronted with leachates
• Great durability, as it made up of PP and HDPE, chemically stable elements that do not rot, they are not sensitive to salt water also offers resistance to oxidation and microorganisms.

Why These Geotextiles in a Landfill?

• The geotextile provide excellent filtration to geocomposite and geonets for gas and liquid.
• The geotextile separate suspended solid particles from draining liquids and prevent clogging geonets and piping systems.
• The geotextile provide excellent cushioning to geomembrane and protect it from puncture damage.
• The geotextile has great resistance to traction and elongation, which is important for slope stability.
• The geotextile has excellent friction properties with HDPE geomembranes and Geosynthetics Clay Liners.
• The geotextile installed on top of the leachate collection pipe system to prevents any clogging of perforated pipes.

The leachate collection and removal systems (LCRS)

The leachate collection and removal systems (LCRS) are generally installed on top of the primary geomembrane layer at the bottom of landfill. The accumulation of water mixed with the breakdown of trash creates a toxic liquid know as leachate.

The purpose of the leachate collection layer is to allow the removal of this leachate from the landfill and transport it to treatment facility. LCRS helps to control the height of the leachate above the geomembrane to keep within the specified limits of the regulating agencies.

Leachate can be removed from the landfill through leachate collection sumps or via a leachate collection header pipe system.

Leak Detection System (LDS)

The leak detection system (LDS) is installed between the primary and the secondary liner. A leak detection system provide rapid detection of major breaches in the primary lining system (within less than 24 hours) and limit the hydraulic head acting on the secondary barrier/layer.

Landfill Capping

The principal function of the capping system is to minimize infiltration into the waste and consequently reducing the amount of leachate being generated.
Other functions are to promote surface drainage and maximize run off; to control gas migration; and to provide a physical separation between waste and vegetation.
Cushion to Lining System

The nonwoven geotextiles play integral part in landfill lining system to protect any kind of damages to liners (geomembrane) during construction and operational phase. The  nonwoven geotextiles are deployed above, below or both sides of the low permeable geomembranes as a cushion to protect the geomembranes against damage from drainage stones or alternate media during construction. It also protect against damage caused due to dumping of waste during operational phase of the landfills.
The nonwoven geotextiles weighing from 10 oz/sq yard to 32 oz/sq. yard are specifically designed as cushion to waste containment lining system.

Filtration and Drainage System

The nonwoven geotextiles provide excellent performance as filter when used with natural drainage media, geonet or geopipe. The geotextile filters solids (soil and waste) and allows liquid (rain water or leachate) to efficiently drain through designed drainage system.
The nonwoven geotextiles weighing from 4 oz/sq yard to 10 oz/sq yard are specifically designed as filtration/drainage geotextile.

ENVIRONMENTAL – PONDS

Ponds are artificially created for fluid storage systems which are designed commonly using geosynthetic materials. Ponds can be of various types depending upon applications such as; Leachate Ponds, Brine Ponds, Wastewater Ponds, Containment Ponds, Gravity Ponds, Raw Water Storage Pond, Pregnant Solution Ponds etc.

Why Use These Geonet and Geocomposite for Ponds?

A geonet or geocomposite are great drainage options for low slopes and can also withstand high loads which make an ideal system by providing drainage to migrating gases and liquids. SKAPS geonet and geocomposite offer better protection to geomembrane and is the most cost effective solution for drainage in pond applications:

• Major components of Pond
• Groundwater drainage
• During the construction of ponds, underground running water and water tables may be intercepted, which must be drained to eliminate the hydrostatic pressure and guarantee the stability of the structure.
• Capture and drainage of gases
• The geonet and geocomposite provide better gas drainage solutions beneath ponds. Often the subsoil has entrapped gases that travel upwards and accumulate beneath the impermeable barrier such as geomembrane. These gases create uplift pressure on the impermeable barrier which can ultimately affect the integrity of the impermeable barrier and destabilize the pond systems.

ENVIRONMENTAL – MINING

In Heap Leaching technology for mineral processing, large piles of mineralized rocks are irrigated with alkaline or acidic solutions to leach the intended mineral. Generally leach pads are conventional, dumps, valley fills and dynamic on/off pads.

• Conventional pads are comparatively flat and the ore is stacked in thin layers (Upto to 15 meter).
• Dumps are similar to conventional pads but the ore is generally uncrushed and very low grade.
• Valley fills are built in natural valleys with buttress dams at the bottom of valley or a leveling fill within the valley.
• Dynamic pads are graded to near flat plane since off-loading requires accurate information of the liner system relative to depth

The overburden stress on the liner system is the depth of the ore times the density of ore.

Geocomposite Liner Drainage System

Crushed stone with specific requirements are expensive and not easily available to deliver at jobsite. It is not advantageous to place crushed stone directly against geomembrane. An alternative is necessary which is cost effective and reduce construction time with ease of availability. The geocomposite, that is TRANSNET geonet bonded to one side or both sides with a nonwoven needle punched geotextiles. TRANSNET geonet made with high density polyethylene does not crush under high normal pressure of ore in heap leach pads. The geotextile act as a filer media and helps smooth, uninterrupted flow. The installation is faster than laying crushed stone and damage to geomembrane is minimum compared to crushed stone layer.

Geotextiles in Mining Application

In Heap leaching operation mined ore is usually crushed into small chunks and heaped on a geomembrane and/or clay lined leach pad, where it can be irrigated with a leach solution to dissolve the valuable metals.The crushed ore containing gold is irrigated with a dilute alkaline cyanide solution. Sulfuric acid is used to dissolve copper, nickel and uranium from its ores. So aggressive liquids are used in this process and the geosynthetic materials used in this application have to be chemically resistant across a wide ph range.
A geomembrane liner beneath heap leach stacks provides a primary containment barrier for leach solutions with proper liner selection and installation. Underlying the geomembrane there is a fine grained bedding fill to protect the overlying geomembrane liner from sub grade rock puncture . This layer is not readily available and non-woven geotextiles offer a great economical, factory manufactured solution to the problem. The non-woven geotextiles can be used directly underneath the geomembrane for cushion purposes.

The pregnant solution is collected and transported out of the heap mine using a network of collection pipes. The solution collection pipes survivability and long term flow capacity is often a engineering design problem. The non-woven geotextiles can be incorporated in the design for filtration function and offer superior solution in comparison to just having gravel in a collection sump or a collection trench.

Cost Comparison

The crushed stone layer costs is about one-third of the total cost of liner system and crushed stone costs have been escalating at significantly higher rate than other construction costs. The gravel is also a problem with cost overruns and project delay. The Geocomposite can be used instead of gravel layer partially or completely at a lower cost. It also provides cushion and protects the liner from damage and helps to minimize punctures of the geomembrane.
Performance

The geocomposite can withstand higher compressive loads, which makes it appropriate to use as a drainage and protection layer under higher loads of large heap leach pads. The SKAPS geocomposite provides better in-plane flow capacity to transport leaching solutions under very high overburden loads.