River Humber Gas Pipeline Replacement Project
Work has been carried out on a £100m project to create a tunnel under the River Humber to carry one fifth of the UK’s gas supply to millions of homes.
The three-mile tunnel houses a new gas pipeline running between Goxhill in North Lincolnshire and Paull in East Yorkshire and was expected to take a year to build. National Grid needed to replace the current pipeline, which is in a trench just below the river bed and is at risk of being exposed by the tides.
The crown of the TBM passed 7m underneath an existing in-service gas pipe, approximately 10” in diameter and a few hundred meters from the reception shaft on the Paull side. On this existing gas pipe in-service, three spots were monitored for changes in strain as the pipe falls in the zone of influence of the TBM.
- River Humber Gas Pipeline Replacement Project
- March 2019
- National Grid
- Skanska, Porr Bau, A. Hak – Humber
- Instrumentation Specialist
A total of nine Geosense VW Strain Gauges Surface Mount VWS-2000, bonded, were installed in three groups of three on the gas pipe in-service. Three were bonded at the projected centre line of the TBM and two groups were installed 13.1m from the centre line, to the north and to the south.
Each group had one VWS-2000 installed at the top of the gas pipeline and two at each side, spaced 120° to the top, central one.
Three wireless Wi-SOS 480 data loggers were installed, one for each of the groups. The data from these Wi-SOS dataloggers was forwarded to the Web through a Wi-SOS gateway, installed 300 metres away, in the JV’s site office.
Three months of base-line, site zero reading was measured and calculated and data uploaded onto GeoAxiom visualisation software and threshold trigger levels set to check for changes in strain as the TBM passed under.