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Yellow excavator on a construction site placing gravel on top of a reinforcing Naue Combigrid® geocomposite layer.

Temporary access roads and haul roads

Stabilise access roads: geosynthetics for soft ground and haul roads

Temporary access road and haul road stabilisation refers to the engineering of load-bearing unpaved surfaces on weak or variable subsoils. Soft ground, heavy vehicle movements and repeated traffic loading cause rutting and loss of bearing capacity. Secugrid® geogrids and Combigrid® geocomposite products distribute loads, reduce aggregate consumption and maintain surface integrity throughout the construction or operational period.

At a glance

  • Application: Engineering of load-bearing unpaved surfaces on weak or variable subsoil for temporary or permanent access routes, haul roads and construction site roads (base course reinforcement).
  • Products: The primary Naue products are Secugrid®, Combigrid®, Secutex®.
  • Savings potential: Over 40 % less aggregate achievable with Combigrid®, project-dependent; 20 % documented (Land & Water Ltd, 2023).
  • Standards: Design follows EBGEO, BS 8006-1, BRE BR470, RStO, ZTV E-StB.
  • Typical projects: Typical projects include wind farm haul roads, mine site access tracks, construction site roads.

Temporary access road stabilisation: fast track to bearing capacity

Challenges

  • Soft or variable subgrade (CBR < 3 %)
  • Rutting under repeated heavy vehicle passes
  • Fine particle migration contaminating the base course
  • Tight construction schedules and cost pressure
  • Remote or difficult site access

Solution

  • Secugrid® geogrid for base course reinforcement and load distribution
  • Combigrid® geocomposite combining reinforcement with separation and filtration in one layer
  • Secutex® nonwoven geotextile as a standalone separation and filter layer
  • Double-layer Secugrid® systems for extremely soft peat subgrades (CBR < 1 %)

Outcome

  • Over 40 % less aggregate achievable with Combigrid®, project-dependent; 20 % documented (Land & Water Ltd, 2023)
  • Immediate load-bearing surface, even on peat
  • Reduced rutting and longer service life under heavy traffic
  • Faster installation vs. soil replacement or deep ground improvement

Typical applications for temporary access roads and haul roads

Secugrid® and Combigrid® deliver reliable bearing capacity wherever ground conditions challenge conventional construction.

  • Wind farm haul roads

    Wind farm haul roads

    Stabilise haul roads across soft peat and moorland for turbine transport and wind energy construction.

  • Mine site access roads

    Mine site access roads

    Provide durable access to mining facilities under heavy equipment loads and variable ground conditions.

  • Construction site roads

    Construction site roads

    Create load-bearing site roads quickly on variable subgrade conditions for fast-track project delivery.

  • Forestry and sawmill roads

    Forestry and sawmill roads

    Reinforce log yard haul roads and forest access tracks on weak soils for year-round operation.

  • Temporary compounds

    Temporary compounds

    Stabilise site compound and substation ground on undisturbed land with minimal surface preparation.

Construction site stabilised with Naue Secugrid® geogrid with an excavator lifting a geogrid roll in the background.
Construction site stabilised with Naue Secugrid® geogrid with an excavator lifting a geogrid roll in the background.

Robust in installation - reliable in performance

Temporary access roads and haul roads face intensive installation loads from heavy plant and compaction equipment. Naue geogrids are engineered to offer high resistance to installation damage. They maintain structural integrity under compaction forces and rough aggregate.

Practical advantages for site teams:

  • High tensile strength at low elongation keeps the base course stiff under repeated axle loads.
  • 4.75 m wide rolls minimise cutting waste and reduce the number of seams on site.
  • Combigrid® combines geogrid and nonwoven geotextile in one roll, reducing installation steps and site logistics.
  • Double-layer Secugrid® systems are specified for floating road construction on peat with CBR < 1 % (source: Benbrack Wind Farm).
  • No specialist installation equipment required: the geogrid or geocomposite is unrolled directly onto the prepared subgrade surface.

Step-by-step installation sequence:

  1. Prepare and proof-roll the subgrade surface to verify bearing capacity and remove standing water.
  2. Unroll Secugrid® or Combigrid® directly onto the subgrade; no mechanical fixing required.
  3. Overlap adjacent rolls by a minimum of 500 mm longitudinally and 300 mm at end joints.
  4. Place and spread the aggregate base course to the specified depth according to the design calculation.
  5. Compact the aggregate with a vibrating roller to the target density; traffic may commence immediately afterwards

Temporary access roads and haul roads: frequently asked questions

Temporary access road stabilisation with geosynthetics describes the use of geogrids or geocomposites placed between a soft subgrade and an aggregate base course to distribute vehicle loads, prevent rutting and reduce aggregate consumption. Secugrid® and Combigrid® are the standard Naue solutions for this application on soft ground.

Combigrid® is recommended when the subgrade CBR is below 3 % and fine particle migration into the base course is a risk. On soft cohesive or peaty subgrade, the combined reinforcement, separation and filtration function of Combigrid® protects the base course and extends road service life beyond what a geogrid alone achieves.

In the UK, BRE BR470 governs working platform design and is widely applied to haul road calculations. BS 8006-1 provides broader guidance on soil reinforcement. In Germany, EBGEO is the primary design standard. RStO and ZTV E-StB apply to German access road projects. Naue Portal’s “UnpavedRoad” calculator incorporates these standards for rapid project-specific design.

On the Blenheim Lake Restoration project (UK, 2023), Combigrid® 40/40 Q1 GRK 4 C reduced aggregate volume by around 20 % compared with an unreinforced design (source: Land & Water Ltd project manager Charlie Oakes). Depending on the project, savings of over 40 % are achievable with Combigrid®, as shown by the Naue “UnPaved Road” calculator (naue.com). Savings vary depending on subgrade conditions and design traffic loading.

The geogrid or geocomposite is unrolled directly onto the prepared subgrade surface; no specialist equipment is required. Aggregate is then placed and compacted onto the product. Combigrid® reduces installation steps as geogrid and geotextile are delivered in a single roll. 4.75 m wide rolls minimise longitudinal seams and on-site waste.

Yes. Secugrid® and Combigrid® are used on mine site access roads and haul roads globally, including in Australia, Canada, South Africa and Chile. The products handle heavy-duty loads from mining equipment and perform in challenging environments including variable rainfall and weak subgrades.

For projects in North America, AASHTO design methods are applicable alongside BRE BR470 and BS 8006-1 for international reference. Naue’s Engineering & Design Department (EDD) can advise on jurisdiction-specific requirements and supports project-based design calculations. Design references also include EBGEO (Germany) and RStO / ZTV E-StB for European projects.

By reducing the volume of aggregate required, Secugrid® and Combigrid® solutions reduce quarrying, processing and heavy haulage. Locally available recycled materials may often be used as fill.

A geogrid such as Secugrid® provides tensile reinforcement to distribute loads and reduce aggregate depth but does not prevent fine particle migration. A geocomposite such as Combigrid® combines a geogrid with a nonwoven geotextile in a single roll, delivering reinforcement, separation and filtration simultaneously. Combigrid® is the preferred solution when subgrade CBR is below 3 % and fine contamination of the base course is a risk.

Yes. Although frequently specified for temporary construction access roads, Secugrid® and Combigrid® are equally suitable for permanent unpaved roads and haul roads with design lives of 20 years or more. Design calculations follow the same methodology, with higher design traffic loading factors applied for permanent infrastructure. The “UnpavedRoad” calculator is available in the Naue Portal on our website and supports both temporary and permanent road design.

Unpaved road stabilisation: design according to EBGEO, BS 8006-1 and BRE BR470

The design of geogrid-reinforced haul roads and temporary access roads follows recognised national and European standards. Naue Portal’s “UnpavedRoad” calculator supports engineers in determining the optimum Secugrid® or Combigrid® system for specific subgrade and traffic conditions - quickly, reliably and in line with current standards and common methods:

  • EBGEO: Recommendations for geosynthetics in earthworks and foundations - base course reinforcement chapter. Primary design standard in Germany and widely referenced across European projects.
  • BS 8006-1: Code of practice for strengthened / reinforced soils and other fills. Standard reference for UK civil and haul road projects.
  • BRE BR470: Working platforms for tracked plant - standard for temporary haul surfaces and working platforms in UK construction, wind farm and piling sites.
  • RStO/ZTV E-StB: German guidelines for road base design, applicable to German access road and site road projects.
  • AASHTO: American Association of State Highway and Transportation Officials flexible pavement method. Applicable to North American mine and haul road projects.
Excavator spreading gravel over a large Secugrid-reinforced construction site. with workers in high-visibility vests nearby.
Excavator spreading gravel over a large Secugrid-reinforced construction site. with workers in high-visibility vests nearby.

How Secugrid® and Combigrid® work in the layer structure

The following system benefits come directly from how the Naue products work within the layer structure:

  1. Reinforced base course: Secugrid® distributes vertical stresses horizontally, reducing settlement.
  2. Reduced aggregate depth: the same bearing capacity with over 40 % less aggregate achievable with Combigrid®, depending on the project (Naue “UnPaved Road” calculator which can be found in our NauePortal).
  3. Separation and filtration (Combigrid®): The nonwoven layer prevents fines migration and maintains drainage.
  4. Improved surface quality: less rutting under repeated heavy vehicle passes.

Downloads and services

  • Geogrids enables access to Europe’s second biggest waterway junctionYouTubeWatch
  • Removal of geosynthetics using spreader bar – clean separation and safe roll-upYouTubeWatch
  • Economic and safe - new paths for a sustainable infrastructureYouTubeWatch

Geotechnical software

Naue Portal - the free digital platform for geotechnical engineers.

Naue Portal: your all-in-one free geotechnical software solution for planning and cost estimation

  • One platform – multiple solutions: access a wide range of geotechnical design tools in a single portal.
  • User-friendly and accessible: available anytime, anywhere via desktop or mobile.
  • Optimised cost and material usage: reduce construction costs while ensuring long-term project stability.
  • Compliant with industry standards: aligns with AASHTO, and other engineering guidelines.