Ground Reinforcement & Subgrade Stabilisation

Ground Reinforcement & Subgrade Stabilisation

Geosynthetics provide many benefits over traditional construction techniques where soils, subbases, subgrades, foundations, slopes and trafficked surfaces are constructed. By reducing traditional stone construction layers the use of geogrids, geocells and geotextiles have become the engineered, environmental and cost-effective solution for such civil engineering projects.

ABG has an extensive range of geosynthetics used in reinforcement and stabilisation applications including surface reinforcement, slope stabilisation and subbase stabilisation.

ABG’s technical team are able to provide technical support for all applications ensuring that the correct product solution is supplied.

Typical applications

• Soil stabilisation
• Ground stabilisation
• Basal reinforcement
• Roadway subbase reinforcement
• Steep slope stabilisation
• Tree root protection
• Reinforcement for car parks and access roads

Benefits

• Reduces the depth of the subbase
• Strengthens subbase construction
• Cost-effective alternative to stone
• Reduction in stone transportation costs
• Geotextiles provide filtration & separation functions
• Geogrids help reduce subbase thickness
• Geocells reinforce slopes and embankments
• Strengthen weak soils in horizontal applications

Typical Client Profile

• Highway Engineers
• Civil Engineering Contractors
• Landscape Architects
• Rail Engineers
• Local Authorities
• Parks and Private Estates

ABG supply a range of geosynthetic product solutions that provide reinforcement and stabilisation for soils, slopes and subbases:

Geogrids

Abgrid biaxial geogrid is used in a range of civil engineering applications such as ground reinforcement, subbase aggregate reduction, basal reinforcement, paved and unpaved road foundations, permeable paving construction, retaining walls and steep-sided soil embankments.        

Road Foundation Design using CD225

According to the Design Manual for Roads and Bridges (DMRB) document CD225 revision 1 (2020), clause 2.7, Note 2: “Options for improvement of the subgrade include excavation and replacing between 500 to 1,000 mm of the soft subgrade with granular fill, mechanical stabilisation (geogrids and/or geotextiles) and soil stabilisation”. ABG can propose a stabilised foundation solution to compensate for lower CBR strength values (i.e. less than 2.5%) and achieve the foundation class requirements. The design for all foundation areas shall be based on achieving a foundation class selected from Table 3.7 in CD225:

Email: technical@abgltd.com *protected email* for a free CD225 Design Assessment

Geogrid Reinforced Flexible Pavement Design using AASHTO method

ABG can offer a stabilised, reduced road foundation thickness by incorporating the benefits of geosynthetics in terms of improved layer stiffness within the AASHTO pavement design method. The drainage performance of the unbound foundation layers can be improved significantly by introducing ABG’s bespoke drainage geocomposite products, which eventually enhance the trafficking life of the whole pavement and reduces the cost of the project.

Geotextiles

Geotextiles help reduce subbase thickness and provide a filtration and separation function. Terrex NW geotextiles provide aground stabilisation by separating angular stone layers within a constructed subbase. By allowing water to percolate through, subbases are stabilised as the intermixing of different construction layers and subgrades is stopped.

SG 60-60 is a high performance woven geotextile engineered for soil reinforcement applications and for strengthening a wide range of soils by spreading and confining angular aggregate layers so that weakening of the subgrade is prevented.

Geocells

Typical geocell design applications include pavements, retaining walls, slope stability and embankment construction. Geocells provide an added advantage to planar reinforcement, with the three dimensional honeycomb cell structure providing a confinement system when infilled with compacted fine soils or aggregates and subjected to surcharge loads.

Abweb geocell and Abweb TRP (Tree Root Protection) geocell act as a load spreader when vehicles or heavy machinery is trafficking over the system. The three dimensional geocell mattress also helps to mitigate differential settlement into soft soils, improves shear strength and enhances load-bearing capacity. The installation of the Abweb geocells reduces the amount of aggregates required and the service life of the paved/unpaved roads is extended.

             Abweb geocell                                              Abweb TRP geocell

The Erosaweb system provides stabilisation for earth slope structures where vegetation growth may be difficult. The system mitigates against potential erosion forces and contains the soil fill, with the perforated pockets allowing drainage in order for root systems to successfully establish. ABG’s experienced Engineers can help with selecting the right geocell product to meet the project’s specific requirements.

Erosaweb geocell illustration

The Webwall geocell system for constructing steep slopes (up to 70°) creates a sustainable green retaining wall to resist backfill pressure and the loadings imposed onto the crest of the structure. The Webwall system can meet the aesthetic demands of architects and engineers where a green slope face is desired. It is installed and backfilled in layers, with site won fill generally suitable, in order to form a mechanically stabilised soil structure. Depending on the height, loadings and geometry of the crest, geogrids may also be specified as part of the Webwall design.

Webwall application illustration

The ConcertinaWeb system is a long-term, cost effective option for preventing road side verge failures and material scatter in the event of vehicle over-run.

Concertinaweb function diagrams

Permeable Paving Surfaces

Sudspave porous plastic pavers provide a reinforced gravel or grass surface intended for traffic applications. Suitable for car parks, access roads, driveways and paths. For heavier load-bearing applications; including HGV access and crane hardstandings, Truckcell permeable plastic paving blocks should be considered.

Sudspave installation illustration

Reinforced Grass Surfaces

Advanded Turf is a system that uses plastic mesh elements mixed with a specially selected rootzone to reinforce grass for occasional traffic, landscaped areas and amenity area usage.

Advanced Turf System illustration