Tales From a Riverbank

Geoforte provided a stream embankment remediation solution for major housing developer Persimmon Homes at Alder Stream, Five Oak Green Tonbridge. This project proved challenging on many levels with special consideration being given to environmental issues on site and downstream, limited accessibility and  working space between the stream bank and the existing property development.

This ecologically sensitive project involved careful planning as a balance had to be struck with providing an earth retention  solution which was suitably robust to prevent further erosion and failure of the existing bank whilst giving due consideration  to all environmental issues.  A full topographic survey of the stream area was carried out with supplementary SI in the form of window sampling to determine existing  the soil properties. This allowed for a design solution specifically tailored to the segment of the stream being remediated.

Detailed design led to a hybrid solution which utilized ground anchors with a gabion mattress stone filled face. This allowed for minimal excavation and disturbance to the natural habitat while providing a structural solution within the existing site constraints.

The construction was undertaken using temporary scaffolding within the stream with excavation and muck away done manually. Care was taken to minimize the potential spill of excavated soil into the stream with silt traps placed downstream as a precautionary measure.

No mechanized equipment was used along the stream bank due to limited accessibility and the possibility of damaging the already fragile banks on the opposite side of our works.

Top soil was used to re-grade the slope above the gabions in order to encourage the re-growth of indigenous vegetation over the top edge of the mattress .This will allow for the blending in of the gabion face with the natural vegetation.

The work was completed without any damage to the environment and the original stream width was maintained and widened slightly in some areas to maintain uniformity which  was verified by an as built survey upon completing of the works.

Geoforte Motor On

Major Civil Engineering Contractor Skanska has employed Geoforte on a tricky and tight access project to build bridge abutments, wing walls and associated drainage for the new Catthorpe Viaduct over the M1 at its junction with the M6 using a reinforced earth modular block dry build system.

Working under a strict Health and Safety and Quality Assurance regime within a phased programme of construction immediately adjacent to a motorway contraflow, our direct works team’s activities also had to dovetail into the reinforced concrete wall build which was being carried out in sections in parallel by Skanska.

Close coordination with the Principle Contractor including regular briefings, early and ongoing workforce involvement and effective communication on site through progress meetings are paying dividends in build time and the implementation of safe working methods.

Checkout this new build for Tesco

An 8m high cut face and the need to minimise excavation and import of granular fill were the main considerations for us on this scheme. The solution was further complicated as the boundary to the site was very close to the crest of the new wall ruling out ground anchors or soil nails and making it quite a challenge for our design (and construction) team. A hybrid approach was adopted using part gravity and part tie back structure with a timber crib facing linked to no fines concrete backfill in the lower cut sections of the wall and reinforced earth elements in the fill upper zone.

Work is progressing steadily on site now with close coordination of excavation, wall face build, infilling and backfilling in order that the bank integrity is maintained throughout, particularly through periods of inclement weather.

Grow bags are being inserted into the wall in order that the face can be planted out on completion.