DIRFT III A5 Weir Works

After several flooding incidents, Prologis UK Ltd set out to create the A5 weir works flood protection project. Their goal was to improve safety on the nearby A5 and to the Daventry International Rail Freight Terminal (DIRFT).

Adhering to the Highways England requirements of minimal traffic disruption throughout the construction stage was a key factor to the project. This meant optimising the space available to allow the A5 to continue dual direction traffic over one half of the culvert. We increased the already confined space by applying an unconventional 38° skew angle to the culvert units which provided additional working space and simplified the traffic management arrangements.

A wide spectrum of services enabled efficient data transfers and working throughout the duration of the project. The structures team worked alongside the hydrology team who modelled the Clifton Brook that passes through the culvert. Work performed by our geotechnical team allowed for a seamless transfer of soils data which the structures team could utilise to gain a greater understanding of the stratum the culvert was to be founded on and the allowable bearing pressures available.

The culvert has now increased motorist safety along the A5 and incorporated sustainability factors by using hydro modelling for climate change. It also includes environmental infrastructure such as mammal shelves to allow wildlife passage under the carriageway.