132kV Cable Protection Measures

Our works on the Glasgow Airport Investment Area (GAIA) project involved providing protection measures to a series of fragile high voltage (132kv) cables which one of our new roads has to cross. Preliminary proposals for the protection measures involved a series of steel-reinforced concrete beams spanning an array of reinforced concrete piles.

This solution was highly carbon-intensive, and the asset owner (Scottish Power Energy Networks) had raised concerns about the potential for damage to the cables during any vibratory works such as piling. This was particularly relevant because the cables were extremely sensitive and had strategic importance in providing an electricity supply to a large area of Renfrew and Glasgow. An assessment into the carbon footprint of the project proposals undertaken at pre-construction stage determined that the original reinforced concrete proposals had an impact of 1,546.3 tCo2e, which was almost 13% of the whole project’s projected footprint.

We explored alternatives with our designer while prioritising solutions which minimised disturbance to the sensitive assets and utilised sustainable materials. The final solution involved the innovative use of Wavin Aquacell units (recycled plastic hollow crates – typically used for storage in drainage applications), geogrid reinforcement and lightweight concrete and fill which minimises the self-weight loading of the protection measures and avoids disturbance during installation. The carbon footprint of this solution is a fraction of the original proposals due to the elimination of reinforced concrete in favour of hollow recycled plastic crates (which are 95% voids)’.