Design
On previous sewer contracts, UEA upsized existing mains using thrust boring equipment – a specially designed cutter was designed to follow the existing pipes and then install a steel case into which a new carrier pipe was installed and grouted. This option was presented to the client and after reviews of the proposed work method statements, the process was adopted as the preferred installation method. UEA manufactured the required cutter heads with the guides for the existing pipelines – the only constraint was that all excavated and augured material had to be removed, bagged and sealed by an authorised asbestos removal company.
Construction
UEA used its 160 tonne auger boring machine. Three crossings had to be completed as part of the removal process, all of which had a new 300mm reinforced concrete pipe installed inside the steel casing.
- Bore 1 – 12 metres of 450mm steel case
- Bore 2 – 54 metres of 900mm steel case
- Bore 3 – 54 metres of 900mm steel case
COMPLETION
The unique nature of this project required UEA to think outside of the box and deliver a specific scope. At all times the potential contamination was managed to ensure there was zero impact on the workforce and the general public. The project was delivered successfully for all involved.
