The combination of segmental units and geosynthetic layers act together creating a coherent mass to resist the destabilizing forces generated by the retained soil and applied surcharge loadings. This compatibility is achieved by friction 5 and passive resistance. Segmental retaining walls best practices guide ncma etek. The wall units weigh in at from 1,300 to 3,290 pounds and display 6 square feet of face area.
Properly designed, walls reinforced with versa grid 1. Properly designed, walls reinforced with versagrid 1. Prepare to install versa grid by placing versa lok units, backfilling and properly compacting soil fill and drainage aggregate up to the height of the first lowest soil reinforcement layer that is specified on the final, professionally engineered construction drawings p. Properly designed versalok walls with versagrid soil reinforcement can be constructed to heights of 50 feet or more. Properly designed versa lok walls with versagrid soil reinforcement can be constructed to heights of 50 feet or more. Batter mbw unitgeosynthetic reinforcement mbw value al a. Apr 17, 2009 a stepbystep guide to versa lok standard retaining wall construction. Geosynthetics do not act as tiebacks for wall faces. Soil reinforcement for segmental retaining walls versalok. Gec 11 design and construction of mechanically stabilized earth. Geosynthetic reinforcement shall consist of hightenacity pet geogrids, hdpe geogrids, or geotextiles manufactured for soil reinforcement applications.
Reinforcement improves the mechanical properties of a soil mass as a result of its inclusion. Uniaxial grid a geogrid which has been manufactured with high tensile strength and modulus. The type, strength and placement of the geosynthetic reinforcement shall be determined by procedures outlined in this specification and the ncma design manual for segmental retaining walls 3rd. Soil reinforcement for segmental retaining walls up to 6 feet in height. External props and facing units were not perfectly rigid, and. Properly designed, versagrid reinforced walls may be economically constructed to heights exceeding 40 feet. The sand soil was placed and compacted in 125mm lifts. Ab reinforcement grid is biaxial which means it has the same strength in both directions and can be simply rolled out along the wall. Aug 05, 2009 versa grid or comparable geogrid soil reinforcement may be required on walls in which the weight of the wall alone is not enough to resist anticipated soil pressures. Engineered for durability and long life, versagrid geogrid soil reinforcement is a highperformance soil reinforcement composed of highmolecularweight, woven polyester yarns with a polymeric coating. With proper soil reinforcement and design, versa lok walls can be constructed to heights in excess of 40 feet. Uniaxial black highdensity polyethylene geogrid retaining wall reinforcement product overview it is manufactured using select grades of highdensity polyethylene hdpe resins that resist elongation, or creep, when subjected to high loads for long periods of time. Soil reinforcement nilex geotextile materials, erosion.
With proper soil reinforcement and design, versa lok standard walls can be constructed to heights in excess of 50 feet. Geogrid reinforced soil masses create the same effect as having an. Approved products list mbw unitgeosynthetic reinforcement combinations, 20 july 2004 strength of soil reinforcement plf. It is made with polyester yarns that have a high molecular weight and extraordinary tensile strength. Geogrid reinforced walls should be designed in accordance with local australian standards as4678 and are designed for the failure modes stated in the. The aim of this test was to validate the benefit of geogrid reinforcement in a realistic track environment. Geogrid is a ground reinforcement fabric which provides strength to retaining walls and helps to prevent against collapse. Sep 05, 20 it is a type of geosynthetic material, used as a soil reinforcement.
Rather, geosynthetics and soil combine to create reinforced soil structures that are strong and massive enough to resist forces exerted on them. Definitions of terms and abbreviations geogrid a polymer grid structure specifically manufactured for use as soil reinforcement. The sand castle test takes two cylinders of soil and applies vertical force to see how the soil performs. Consult a qualified engineer if you are unsure about any construction, site, or soil conditions. Mechanically stabilized earth mse walls, reinforced soil slopes rss, soil reinforcement, geosynthetics, specifications, contracting methods 19. Versagrid or comparable geogrid soil reinforcement may be required on walls in which the weight of the wall alone is not enough to resist.
Certify and document the submittal values for the following items for each geogrid soil reinforcement used on. Soil types, drainage, loading, topography, and height need to be addressed on each project to ensure safe, troublefree installation. Its flexible, with virtually no memory, so it lays flat after being unrolled. Part 9 soil reinforcement retaining wall installation. This specification supersedes any and all prior specifications for the product designated above and is not applicable to any product shipped prior to. Geosynthetics for soil reinforcement are then discussed in some detail, with specific applications to embankments on soft foundations, steep slopes, and for the backfills of retai n ing walls and. For reinforced soil structures it is important that the reinforcement be compatible with the soil. For long term satisfactory performance of the reinforced slope, the forces in the soil must be transferred to the reinforcement i and vice versa. The design and installation guidelines manual for each type of versalok. Properly designed versalok walls with versagrid soil reinforcement can be constructed to heights of 50 feet or taller. Taller walls require soil reinforcement designed by a qualified engineer. Mosaic construction details cdrom containing drawings created with autocad software. Tensile load in the grid is generated at very small deflections of an applied vertical load reinforcement benefit can be generated within the loaded area. Construction details cdrom containing drawings created with autocad software.
The properties and performance of tensar biaxial geogrids. Each grid was lightly pretensioned before placement to remove, as far as practical, any warps or slackness in the reinforcement. Properly designed versalok walls with versagrid soil. Versalok square foot specifications nettleton concrete. Certify and document the submittal values for the following items for each geogrid soil reinforcement used on the project. These yarns are then knitted into a dimensionally stable network of apertures to form the geometric grid shape which offers tensile reinforcement to the soil in both the vertical. The combination of these features ensures that, in tensar geogrid reinforced granular layers. This manual is a revision to lrfd and an update to the fhwa nhi. Design manual for segmental retaining walls, using. Gec 11 design and construction of mechanically stabilized.
Combigrids composite structure has an additional advantage. Engineered for durability and long life, versa grid geogrid soil reinforcement is a highperformance soil reinforcement composed of highmolecularweight, woven polyester yarns with a polymeric coating. Geogrid reinforced soil retaining walls are internally stabilized systems wherein the fill reinforced with multiple layers of reinforcement behaves as a coherent composite mass and resists earth. Versa grid or comparable geogrid soil reinforcement may be required on walls in which the weight of the wall alone is not enough to resist anticipated soil pressures. Tensar international corporation 5883 glenridge drive, suite 200 atlanta, georgia 303285363 phone. Provides soil reinforcement for segmental retaining walls up to 6 feet tall. Geogridas a soil reinforcement linkedin slideshare. Prepare to install versagrid by placing versalok units, backfilling and properly compacting soil fill and drainage aggregate up to the height of the first lowest soilreinforcement layer that is specified on the final, professionally engineered construction drawings p. Segmental retaining walls best practices guide chapter one preconstruction considerations 5 optional cap finished grade foundation soil reinforced soil geogrid reinforcement retained soil, see section 3. The nineunit bronco 18h system readily accommodates geogrid, such as versa grid, for taller walls. Geosynthetics and soil combine to create reinforced soil structures that are strong and massive enough to resist forces exerted on them. Geogrid 5series, soil stabilization grid 6 x 50 model.
This mechanically stabilized earth walls mse and reinforced soil slopes rss, design. Use the soil reinforcement chart to determine the size of ab grid you will need and how many layers your retaining wall requires. A stepbystep guide to versalok standard retaining wall construction. Test 1 was an unreinforced test, test 2 was a reinforced test with geogrid placed on a single layer of ballast and test 3, a reinforced test with geogrid directly placed on a geotexile while test 4 was. The bronco 18h system is suitable for walls up to 15 feet tall without soil reinforcement. Properly designed versalok walls with versagrid soil reinforcement can be. Stratagrid is a high performance soil reinforcement product. Its composed of highmolecularweight, hightenacity, multifilament. Geogrids can be combined with a wide variety of facing elements in retaining wall and slope applications to produce the desired structural or aesthetic conditions for any project. In soilreinforced walls, standard units simply retain soil between. Versalok soilreinforcement fabric versalok soil reinforcement fabric is an economical, easily installed geotextile designed to provide the additional soil reinforcement necessary for retaining walls up to 8 feet tall. The nineunit bronco 18h system readily accommodates geogrid, such as versagrid, for taller walls. Versa lok offers a variety of technical support including inhouse engineering assistance and reference literature.
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