Project Deep Drainage
Supply and install chambers and deep drainage pipework
In preparation for the larger works to divert the Camden sewer, a number of chambers and 1200mm concrete attenuation pipes were planned to be installed at a depth of 4m, and adjacent to the existing track layout.
2019
Year
£850k
Overall Value
MORGAN SINDALL / NETWORK RAIL
Client
Tony Goble
Contact
The Challenge
Multiple projects were planned at the same time and the deep drainage was directly under the haul road for the main site and would have affected the signal and track upgrade works if traditional excavation methods were used.
Our proposal was to use two of the chambers as a launch and a reception chamber and undertake micro tunneling and pipe jacking to install 125 metres of concrete pipe between chambers.
This novel solution would allow the haul road to remain operational and support the larger works.
Micro Tunneling
Spoor-Tech took an early lead in the design and practical advice on alternative to open cut excavation. We had used micro-tunneling and pipe jacking on previous projects and it would minimise the disruption to the larger project and maintain access to an extremely busy interchange.
A chamber and thrust block was constructed large enough to install the digging shield, jack the pipework and remove spoil from the face excavation as the works progressed.
1200mm pipes are installed using the pipejacking technique. The pipejacking method is by means of a digger shield using a Tunnel Engineering EX1200 mechanical back-actor for excavation purposes, and a conveyor to remove spoil back to the launch chamber.
Powerful hydraulic jacks are used to push specifically designed pipes through the ground behind a shield at the same time as excavation is taking place within the shield. The method provides a flexible, structural, watertight, finished pipeline as the tunnel is excavated. The digger shield is fitted with a laser target and ensures accuracy of direction and fall as the install progresses.
Completion
125 metres of concrete pipe was installed in 2 weeks, below the haul road and adjacent to an operational railway with access maintained throughout.
