South Carolina SCDOT - Secion 203 - Uniaxial Geogrid - U8 - 12' x 200' Roll - 20XT

PRODUCT INFORMATION

TENCATE MIRAGRID® XT UNIAXIAL GEOGRIDS:

TenCate Miragrid® XT uniaxial geogrids are high performance woven polyester and polymer-coated geogrids used for soil reinforcement. TenCate Miragrid® XT uniaxial geogrids are used in Mechanically Stabilized Earth applications including internally reinforced walls, segmental retaining walls (SRW's), and steepend slopes. TenCate Miragrid® XT uniaxial geogrids provide high, long-term design strengths (LTDS) and excellent soil interaction. TenCate Miragrid® XT uniaxial geogrids are constructed of high tenacity, high molecular weight, woven polyester to deliver long-term performance.


The Difference TenCate Miragrid® XT uniaxial geogrids make:

- Flexible and durable
- Excellent creep resistance
- High long-term design strengths
- Lightweight and easily handled
- Cost effective
- Custom fabricated
- System Solutions:

Mechanically Stabilized Earth

- Steepened Slopes: Vegetated and Wrapped Faced
- Walls: Permanent and Temporary
- Segmented Retaining Walls
- Void Spanning
- Veneer Reinforcement
- Soil Reinforcement
- Landfills

Mirafi 20XT Case Study

Overview

The Cherry Island Landfill has been used for municipal solid waste removal since 1985. The island is operated by the Delaware Solid Waste Authority. The site was built on an old disposal site where the Christina and Delaware rivers come together. The landfill is made of soft compressible materials. The DSWA  needed to create a plan to extend the life of the landfill as its waste capacity was maximizing out.  The problem, the present landfill was restricted by the Delaware River to the east, the Christina River to the south, Interstate 495 sits to the west, and there are dredge lagoons to the north. Using horizontal land expansion for the facility was out of the question. The only alternative they had available was a vertical expansion to increase the landfill's capability. In order to vertically expand, they would have to seriously improve the ground measures and use ground reinforcement techniques to make this happen.

Site Designing

The subsurface conditions included dredge material that was approximately 40 feet thick, overlaying a 45-foot thick alluvial deposit. Underlying the alluvial deposit was semi-dense to dense residual, and layer of sand. Because of the soft ground on the sides of the landfill's slopes could not be steeper than 8 Horizontal to 1 Vertical (8H:1V) without serious ground improvement and geosynthetic reinforcement techniques.  Some improvements proposed for the vertical expansion included deep soil mixing, sand drains, and prefabricated vertical drains (PVD). Eventually, the most cost-efficient and construction-friendly option was using a high-strength geosynthetic reinforced berm constructed over the PVDs.  It was anticipated that due to the soft, compressible dredge and alluvial material, a significant settlement was expected. Due to the massive size of the reinforced earth berm, development of very high pore and water pressure in the foundation there was a serious concern. Piezometers and other instrumental devices were brought into the design in order to monitor and prevent the berm from being built too quickly.

Construction

Performance

The construction of the vertical expansion could not have taken place without using high-performance geosynthetics. TenCate Geosynthetics created high-strength polyester reinforcement along with tensile strengths over 80,000 lb/ft to meet the requirements of the site. The vertical expansion was an ingenious design for effectively managing and constructing the massive berm on extremely soft soil. TenCate Mirafi® made it possible for a cost-effective, easy construction solution to a very difficult project. This project was one of 5 finalists for the ASCE 2012 Opal Award for Outstanding Civil Engineering Achievement (OCEA).