NORTHERN CORRIDOR IMPROVEMENTS
The works formed part of the larger Northern Corridor Improvement project. The project was commissioned to connect two existing wastewater treatment ponds and divert the existing TS7 trunk main through a new rout to enable the existing pipe bridge to be demolished prior to constructing the new motorway onramp.
SCOPE OF WORKS
Abergeldie completed multiple motorway crossings using specialist tunnelling machines. Abergeldie also installed a new trunk main via open trench excavation. This included having to cut into the existing trunk sewer and build new chambers at the cut in locations. Co-ordination between Abergeldie staff and Water Care Operations staff was essential to manage isolations for this work to be successful.
INNOVATION AND COMPLEXITY
The three cut-in chambers had to be completed with live flows and no over pumping. The large flow volume in the trunk sewer meant that there was no room for error, as such a special methodology was developed by the construction team to build the chambers around the pipe. This included temporary pipe supports for the existing services and benching being formed and poured at the surface and lowered into place after the Trunk Sewer had been removed from the chamber. This methodology allowed for live flows through out the process and only one pump station had to be shut down for an eight-hour period. The work was successfully completed without any incident or accident.