Unpaved Roads, Car Parks and Windfarm Access Routes

Any temporary or permanent unpaved surface subject to trafficking needs a correctly engineered, but economic design, especially when we talk about weak subgrade conditions. This ensures optimum use of resources and provides a reasonably smooth surface, with tyre loads distributed evenly to prevent rutting and meet the required design life.

Our design department has many years’ experience in designing unpaved roads, car parks and windfarm access roads over very weak CBR subgrades. We are able to offer cost-benefit advice on which solution is best suited to your project, utilising one – or a combination of – geogrids, geocells and geotextiles that deliver a lower carbon footprint.

    Subgrade soil

    Aggregate fill

    Project Geometry and Loading

    Vehicle type

    Number of visits

    Typical cars [w ≈ 10kN (≈ 1 tonne)]

    Light construction vehicles [w ≈ 50kN (≈ 5 tonnes)]

    Fully loaded vans [w ≈ 25kN (≈ 2.5 tonnes)]

    Typical lorries [w ≈ 80kN (≈ 8 tonnes)]

    Heavy tippers and lorries [w ≈ 120kN (≈ 12 tonnes)]

    Note: For construction purposes, we will consider a typical 20t truck (max axle load 97.5kN) in our assessment.


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    Zip file only. Maximum file size 25mb.