Subway - Rochdale

Benefil was the system of choice for Rochdale Borough Council and Mouchel Parkman Impact Partnership when considering methods for filling a redundant subway near Rochdale Town Hall. We chose Benefil because it was a lot easier than using concrete or granular fill, explains the Borough Council's Senior Engineer, John Ashley.

If we'd had concrete, for example, there are access problems and multiple deliveries would have been necessary. Plus if you pump in concrete you have to top it off and grout it up and so on. Benefil is a one-hit wonder, if you like.

The job was fast and straightforward. Services were isolated from the subway, and the client built a solid brick 9-inch-thick wall at one end of the subway. A similar wall was constructed at the other end, with a hatchway to permit access for the hoses, and small vents. The Benefil team then strapped to the ceiling of the subway a 60mm MDPE pipe which they extended to the wall at the far end of the subway, a total length of 30 metres. A second pipe was similarly placed to half the distance, and a third to about 5 metres into the subway. The team then filled the 300-cubic metre subway in three days. The grout was produced on site with only two material deliveries required, a significant consideration for the busy city-centre location.

A similar timescale filling at approx 40 cubic metres per hour is standard for Benefil applications to any site mineshaft, pipeline, culvert or other application.