Dig a little deeper

I was interested to read the article ‘Ditch the Dirt’ in the July/August issue. This implied that soil stabilisation was a relatively new technique, particularly in road building.

I was employed as a graduate engineer on the Ross Spur Motorway (M50) in 1958. The six-mile contract through Worcestershire had a sub-base constructed using cement stabilisation of the underlying keeper marl. It was acknowledged as experimental, with the original designs compiled before WWII.

As I recall the concept was not wholly successful. There was a difficulty in realising a composite bonding of the two-layer process. A ‘sandwich’ layer of untreated soil was left between two treated layers, which proved difficult to overcome. As a result, soil stabilisation was not pursued as a viable design for the subsequent construction of the M5.