Embankment Drainage & Consolidation

Rapid Consolidation using Fildrain, Ashton Moss, Manchester, UK

Project Information

Client:Tameside MBC
Contractor:P Casey
Consultant:TerraConsult
Product:Fildrain 7DD
Quantity250,000m2
Benefits:- Accelerated consolidation
- Embankment reinforcement
- Fast installation
- Allows use of otherwise unsuitable CDEW material


Ashton Moss is a mixed use commercial and leisure development situated off J23 of the M60 near Manchester. The development covers 64 hectares and provides over 1M ft2 of commercial, retail, and industrial space, along with a further 175,000 ft2 of leisure and green open space.

(ref:Published paper “Advanced engineering solutions using geocomposite drainage for fast consolidation in compacted fill Robinson,N. et al. EuroGeo6 Sept 2016)

The Challenge

This large development needed to be completed very quickly to make the development financially viable. The site was a “mountain of pre-tipped inert waste” of very variable specification Construction, Demolition and Excavation Waste (CDEW) that had been stockpiled on a partially excavated and backfilled site including areas of natural peat. It was constrained by the nearby M60, A635 and Ashton North Bypass.

The area was made up of peat and alluvial clays. Surprisingly, the stockpiled material was usable from a geotechnical and contamination point of view but was too wet (23% moisture content) to compact adequately to meet specification requirements, that limited settlement to 25mm within 6 months.

The tight construction timescale meant traditional surcharging was impractical and double handling of the material would have resulted in a massive increase in costs. To meet program, the 700,000m3 earthworks had to be completed over the winter with expected high rainfall.

The Solution

A layer of Fildrain drainage geocomposite was placed every 1m of fill. Using Fildrain 7DD reduced the consolidation period by as much as 80% with the specified settlement complete within 4 weeks. The double cuspated drainage core drains from both sides, while also providing an impermeable barrier that allows vertical migration of pore water but seals against rainfall ingress.

ABG Pozidrain 7D Fildrain 7DD horizontal drainage geocomposite layer

Fildrain 7DD drainage geocomposite is easy to install, avoiding all the difficulties of placing layers of expensive gravel and it was observed that the lower layers were draining effectively even before the upper layers were placed – consolidation starts immediately as the Fildrain is placed.


ABG Fildrain in layers draining embankment

Fildrain drainage geocomposite reduce the embankment consolidation time by reducing flow path of water up and downCell 1 filled to full height to give maximum loading. Fildrain at optimised centres to reduce consolidation time by reducing flow path up and down. Fildrain provided temporary reinforcement of the weak soils. Cell 2 being constructed in second phase
Fildrain reduced consolidation time by 80%Saturated arisings from M60 cutting stockpiled and used in highlighted area with Fildrain reducing consolidation time by 80%
Fully consolidated landform ready for constructionFully consolidated landform ready for construction on time for developers
Fildrain 7DD drainage composite layers for embankment consolidation

The ABG Service

ABG provided full technical support to propose and gain approval from the various authorities for the use of Fildrain 7DD drainage geocomposite. Deliveries were coordinated to fit the work schedule to avoid stockpiling on a tight site.

This scheme is an example of implementing an idea from the Highways England "Managing Down Costs" Toolkit.

Contact ABG today to discuss your embankment drainage or earth consolidation project specific requirements and discover how ABG past experience and innovative products can help on your project.

Fildrain - Fin Drains

Fildrain findrain drainage geocomposite is a cost effective alternative to traditional stone drainage. It collects and channels liquids and gases to a carrier pipe for transportation to a suitable discharge point. Fildrain fin drain has many applications in surface and sub-surface drainage.

more...

ABG Fildrain - Findrain geocomposite from ABG Geosynthetics (Fin Drain)
 

Products

Fildrain - Fin Drains

Fildrain findrain drainage geocomposite is a cost effective alternative to traditional stone drainage. It collects and channels liquids and gases to a carrier pipe for transportation to a suitable discharge point. Fildrain fin drain has many applications in surface and sub-surface drainage.

more...

ABG Fildrain - Findrain geocomposite from ABG Geosynthetics (Fin Drain)
 

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