Contract Service teams from Steve Vick International recently carried out a project for a gas distribution company which involved filling with cementitious grout a 115 metre length of 36” diameter medium pressure gas main.
The decommissioned main in Beddington Lane, Croydon, had been inserted with 630mm PE as part of the gas distribution network’s mains replacement programme in the area. As this section ran beneath a tram line, it was necessary to reinforce the annular space to prevent any future problems with ground slump under the track.
SVI operatives attended site two weeks before the filling operation to fit the company’s END SEALS to either end of the cut main so that the grout would not leak during filling. END SEALS are designed to seal off large diameter inserted or abandoned mains and comprise a fabric muff which is filled with expanding resin foam. This preparatory work allowed contractors, Forefront Utilities, to back-fill the excavations and re-open the road to traffic.
Some 11 tonnes of grout were mixed on site by the SVI team using their specially adapted grout rig and injected through a 2” inlet. Filling took two days to complete. Tony Ward, Forefront’s site manager, commented, “The grout filling operation was a great success. SVI’s team handled it very efficiently.”
With teams based throughout the UK, SVI’s Contract Service is a core function of the business and provides on-site solutions to a wide variety of pipe renewal problems around the country and overseas. Other grout filling projects have included filling abandoned fuel lines at Heathrow Airport, filling annular spaces in pipes on the A2 railway crossing at Dartford and sealing off voids as part of Highway England’s improvements on the A14 near Cambridge.
Grout filling is just one of the techniques used by the SVI Contract Service team working in the gas, water, nuclear and civil engineering sectors.