Geosynthetics in roads and pavements

Document Outline

• Introduction to Geosynthetics 2
• Installation of Interlayers 20
• Installation of Geosynthetics for Structure Drainage 29
• Installation of Silt Fence 39
• Reinforced Steepened Slopes (RSS) 44
• Geosynthetics in Seepage Control Systems 48
• Geosynthetic Support Systems 54
• Geotextiles
• Geonets
  • • Blanket Drain
    • Panel Drain                          Edge Drain
• Geomembranes
• Geopipe
• Fabric Formed Revetments
• Geocellular Confinement Systems
• Silt Fence
• Turbidity Curtains
  • OVERVIEW
• Typical Solutions
• The Geosynthetic Solution
• Stabilization geotextiles can be fabricated into large panels and deployed to expedite road embankment construction
• Design for Stabilization
  • • Geogrid base reinforcement stiffens the aggregate base layer providing long-term support for the paved surface.
• Site Preparation
• Deployment of the Geosynthetic
• Overlap Specifications
  • • When more challenging subgrades are encountered it is often more effective to leave vegetation and construction debris in place.  The geosynthetic will prevent migration of fill soils into the voids within the debris.
    • Aggregate compaction
      • • Damage Repair
• Paving Fabric for Stress Absorption
• Paving Grid for Overlay Reinforcement
• Geosynthetic Benefits
• THE SPECIAL CASE OF CHIP SEALS
• INSTALLATION OF INTERLAYERS
  • • • • • • Surface Preparation
        • Sweeping is an important part of surface preparation
        • Tack Coat Application and Fabric Laydown
          • • Application of the Tack Coat
          • New Construction
            • Geocomposite Edge Drain
• STRUCTURE DRAINAGE
• According to Cedergren, 1989, any well drained structure is inherently safer and more economical than if constructed without drainage.  This is because the placement of relatively impermeable structural elements, such as a concrete foundation or retainin
• Strict adherence to sound drainage principles is probably the most important single aspect of the design of structures constructed adjacent to water-bearing soils.  Almost every serious failure of structures of these kinds has been caused by lack of cont
• The objective of structural drainage is to control water pressures and seepage forces in the earth adjacent to structures and thus prevent their untimely damage, deterioration, or failure.
  • • • • • • Wall Drainage Options
          • OVERVIEW
            • • • Negative Effects of Erosion
                • Erosion vs. Sedimentation
            • Erosion
            • Sedimentation on Roads and in Channels
            • An Undermined Hard Armor System
            • Excessive Drop Height / Damage
            • ROLLED EROSION CONTROL PRODUCTS
  • Erosion is often a problem when there is not enough protective cover on steep slopes or in drainage channels that have been designed to rely on vegetation for long˚term erosion control.  Vegetation is ideal for erosion control because it is relatively in
    • Typical Non-degradable RECPs (TRMs)INSTALLING RECPS ON SLOPES
      • • • • SILT FENCE
            • Typical straw bale installation (failure)
      • Faced with the ineffectiveness of straw barriers, a second type of filter barrier, the silt fence, has emerged.  Silt fences are composed of tough, durable, geotextiles attached to support posts.  Silt fences can trap a much higher percentage of the susp
        • Installation Details
        • Silt Fence Maintenance
        • Geosynthetic Solutions
          • • • Geogrids
        • Details of RSS Systems
          • • OVERVIEW
        • STRUCTURE WATERPROOFING
        • The Geosynthetic Solution
          • • Effective waterproofing includes drainage.
  • Most water reservoirs, because of their magnitude, are lined with low permeability soil and left uncovered.  This often results in high water treatment costs and potentially serious  contamination.
    • PREFABRICATED SYSTEMS
      • • • • Barge-Placed Soil Containment System
            • Sand Containers – Custom Fabricated
    • ON-SITE FABRICATED SYSTEMS
      • • • • Geomembrane Deployment
            • Geomembrane Seaming: Wedge & Extrusion Welding
            • GCL Deployment
        • Testing
          • • Typical QC Index Tests
            • Typical Performance Index Tests
        • Specifying Geosynthetics
          • • Transmissivity and Creep Testing are examples of commonly run design tests.
            • Environmental Stress Crack Resistance testing is a common durability test run on geomembranes
              • • Specifications