California Department of Transportation
 

Wire Mesh Confinement System (Nonstandard)

Welded Wire Confinement System

What is This Treatment?

Slopes steeper than 1:1 (H:V) will not reliably support vegetation and require a more permanent slope face confinement technique than Rolled Erosion Control Products (RECP). A wire mesh confinement system provides the additional sheer strength necessary to hold non-vegetated fill material in place. Key features of a wire mesh confinement system include:

  • Structural backfill material is placed in a wire mesh confinement system, that consists of a double twisted wire mesh enclosure with an articulated front face that can be set to match the desired slope face angle.
  • The bottom of the confinement system can function as a geosynthetic reinforcement layer, enhancing slope stability.
  • Local Topsoil or select material is typically used at the slope face to support sustainable vegetative growth.
  • Rolled Erosion Control Product (RECP) Netting is placed inside the confinement system face to prevent the piping or release of topsoil through the face. The netting has a 63-70% open area that facilitates hydroseeding after slope construction, and is also open enough to encourage seed germination.

The wire mesh confinement system is essentially a double twisted wire mesh containment system with an articulating front face that can be set to a desired angle (see below). The bottom portion of the containment system can run the full depth of the embankment at each layer providing the same function as a geogrid. Select material is used at the face of the wire mesh confinement system to provide a medium for growth. Coir netting is placed inside the basket face to prevent piping of the soil through the face. The netting also allows hydroseeding through the face of the wire mesh confinement system.

Welded Wire Confinement System is also know as Embankment Confinement System.

When to Use This Treatment?

  • Fill or reconstructed cut slopes that are between 1.5:1 (H:V) and 0.5:1 (H:V).
  • To use this product on slopes steeper than 2:1 (H:V) a Geotechnical Design Report should be prepared by the Division of Engineering Services (DES) Geotechnical Design Unit. In addition, a preliminary evaluation may be required by DES Geotechnical Design.
  • Use of this product should be coordinated with the Division of Engineering Services (DES) Geotechnical Design Unit.

DetailWelded Wire Confinement System

Welded Wire Confinement System

Benefits:

  • Provides immediate slope reinforcement
  • Creates slope breaks that shorten slope length and reduce runoff velocities.
  • Increases infiltration rates on dry sites.
  • Provides for vegetation establishment, cover, and natural recruitment.

Limitations:

  • Unsuitable for slopes with limited equipment access.
  • Must have solid footing.

Technical Design Tips:

  • Vegetation is difficult to establish on slopes steeper than 1:1 (H:V), and extremely difficult to establish on slopes that exceed 0.5:1 (H:V).
  • Maximum slope gradient of 0.5:1 (H:V) has been used in extreme cases for slope tie-ins to natural grades.

Specifications:

  • Specifications and details under development.

Consider Using With:

To effectively treat sites with poor soils (compacted, sterile or poorly draining), consider combining this treatment with:

Plans and Details:

Estimate Information:

Guidance:

External Links: