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02 · EVO Rock Bags

Erosion and scour control that is quick to deploy

EVO Rock Bags are flexible nets filled with rock or crushed concrete, used for erosion control, scour control and stabilization of soil.

They are a better solution than loose concrete, gabions, block stone and rip rap: high-performance erosion and scour control that is efficient and effective to deploy, in standard and emergency construction.

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How they work

Decades of civil and soil engineering experience

The rock bags are filled with graded rock as a flexible, ecologically advantageous engineering solution. For erosion and scour applications, the smaller graded rock within the net reduces flow velocities by absorbing water energy into the high interstitial spaces between the rocks, in both fresh and salt water.

Those spaces also provide habitat for invertebrates and accrete fines, gravels and silts, which allows vegetation to establish naturally over time. In soil stabilization, the rock bags become a large mass that complements and integrates with the existing natural structure.

The bags are easy to fill and to handle through a ring that is the single point of contact during installation. Because they are flexible, they conform to the surface, which removes the need for site preparation in most cases.

A filled rock bag being lowered into the water by crane
An excavator placing a rock bag in shallow water

Applications

Common applications, with almost a million rock bags deployed

The rock bags can be used independently or as part of a bioengineering design with vegetated systems above water level, pairing habitat biodiversity with an engineered approach to asset protection.

  • Cross-section diagram: river bank revetment with rock bags

    River Bank Revetment

  • Cross-section diagram: stepped bank revetment with rock bags

    Stepped Bank Revetment

  • Cross-section diagram: bank foot with gabion with rock bags

    Bank Foot with Gabion

  • Cross-section diagram: bridge pier scour protection with rock bags

    Bridge Pier Scour Protection

  • Cross-section diagram: shoreline & intertidal with rock bags

    Shoreline & Intertidal

  • Cross-section diagram: bank & river bottom protection with rock bags

    Bank & River Bottom Protection

Sectors

Where rock bags are used

Advantages

Why specify rock bags

  • Easy to fill

    Easy to fill in a production setting.

  • Quicker to place

    Less work and quicker to place.

  • Safer to use

    Safer to use on site and in the water.

  • Fresh & saline water

    Used in fresh and saline water environments.

  • UV & abrasion resistant

    Highest UV resilience and anti-abrasion of any net product.

  • Bioengineering ready

    Use independently or as part of a bioengineering design with vegetated systems above water level.

Specifications

Rock bag sizes

Metric units
Rock bagMeshRecommended rock size (mm)Height (m)Diameter (m)Volume (m³)Weight, empty with ring (kg)Resistance to currents, single (m/s)Resistance to currents, grouped (m/s)
2 ton25 mm50 – 2000.41.91.136.03.24.7
4 ton25 mm50 – 2000.62.42.7112.53.65.3
8 ton50 mm75 – 2000.853.06.0039.04.05.9
Imperial units
Rock bagMeshRecommended rock size (in)Height (ft)Diameter (ft)Volume (ft³)Weight, empty with ring (lb)Resistance to currents, single (ft/s)Resistance to currents, grouped (ft/s)
2 ton1 in1.6 – 8.01.36.239.2213.210.515.4
4 ton1 in1.6 – 8.02.07.997.9827.511.817.4
8 ton2 in3.0 – 8.02.89.8211.1085.813.119.4

Resistance to currents is the flow velocity at which the bags show no movement, placed singly and grouped.

Technical documents

Additional information

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Contact

Request a rock bag quote

Whether your project requires cryogenic valves, rock bags or manpower, let us be your first contact. We will deliver to your exact requirements and provide a quality solution on time and on budget.