Stabilisation

Sudsweb, Abgrid & Terrex, Devour, Holmfirth,UK

Project Information

Client:Devour
Contractor:Radcliffe Construction
Consultant:ONE17 Architects
Product:Sudsweb GWX Geocell
Abgrid 30/30 Geogrid
Terrex SNW40UV Protection Geotextile
Quantity:500m2 Sudsweb
2000m2 Abgrid
2000m2 Terrex
Benefits:- No additional sub-base depth
- Rapid construction minimum delays
- Used locally to solve local soft spots


Project Description

In 2017 permission was granted to start the redevelopment of a historic abandoned mill in the Thongsbridge area of Holmfirth into a restaurant and cookery school. One of the main attractions was that it was situated in a scenic wooded valley at the side of the River Holme. Even before permission was granted for the development, concerns were raised as to the effects any development might have on local traffic. It was, therefore, essential that a spacious car park be constructed to avoid congestion on neighbouring streets.

The client wanted to create an attractive, permeable and environmentally friendly car park surface adjacent to the river. Planning restrictions also gave strict limits on the discharge rates to the river from the car park.

 DEVOUR Holmfirth

The Challenge

Although the area to the rear of the building provided a large space seemingly ideal for development as a car park and delivery area, it soon became clear that the ground next to the river was soft and required stabilisation. After further investigation, it was revealed that the north part of the car park had a previously unidentified millrace. This supplied water for the original mill and had accumulated a deep layer of silt. The ground in this area had a CBR value of less than 1%. In addition the site required a root barrier system.

To completely dig out the area would be a costly and impractical task and any excavated soil would have to be treated as contaminated waste and externally treated. The soft area was a late discovery when formation level had been cut, so there was little programme time to carry out additional work).

The ground in this area had a CBR value of less than 1%

The Solution

ABG offered a Sudsweb geocell / Abgrid geogrid stabilisation combination over the soft areas, to stiffen the Type 3 attenuation layer and to produce a stable subbase. The depth of stone had to be maximised, so a thick Terrex SNW geotextile protection layer replaced the 50mm sand blinding being used over the geomembrane. Terrex SNW geotextile was easier to place and provided better protection than the sand. Abgrid geogrid was then placed as a basal stiffening layer and Sudsweb tied using Abfix Ties to the grid. This avoided the need for pins which would pierce the geomembrane. Sudsweb geocell was filled with Type 3 attenuation stone and then compacted to finished level producing a firm stabilised surface ready for the placement of the Sudspave permeable paving. (see ABG SuDS Permeable Paving Devour Mill CASE STUDY). No material was removed from site with minimal delay to the filling operation.

ABG Stabilisation solution incorporating a Geomembrane, Terrex SNW geotextile, Abgrid Geogrid Sudsweb Geocell

ABG Stabilisation solution incorporating a Geomembrane, Terrex SNW geotextile, Abgrid Geogrid, Sudsweb Geocell and Type 3 angular aggregate.

Abgrid geogrid installationAbgrid geogrid installation
Installing the Sudsweb geocell onto the protection geotextile and geogrid layersInstalling the Sudsweb geocell onto the protection geotextile and geogrid layers
Sudsweb geocell expanded and attached to Abgrid geogrid using Abfix Ties placed over soft soil areas.Sudsweb geocell expanded and attached to Abgrid using Abfix Ties placed over soft soil areas. Pinning was not allowed as this overlays the Terrex SNW protector geotextile on top of the geomembrane.
The Sudsweb geocell was rapidly installedThe Sudsweb geocell was rapidly installed and at original formation and finished levels.
Sedsweb geocell filled with stone, providing a stable surfaceEndorsement from excavator driver. “Amazing!”

The ABG Service

ABG offered design support and advice, including technical calculations and site visits.

Contact ABG today to discuss your stabilisation project specific requirements and discover how ABG past experience and innovative products can help on your project.

Abgrid Geogrid

Abgrid biaxial geogrid can be used in a wide range of civil engineering applications such as basal reinforcement, ground stabilisation, aggregate reduction, piling platforms and foundation engineering in paved and unpaved roads and temporary works.

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Abgrid Geogrid

Terrex SNW Geotextile

The Terrex SNW geotextile range are engineered to provide unrivalled CBR puncture resistance and tensile strength offering maximum protection at optimum cost levels.

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Terrex SNW Geotextile
 

Products

Abgrid Geogrid

Abgrid biaxial geogrid can be used in a wide range of civil engineering applications such as basal reinforcement, ground stabilisation, aggregate reduction, piling platforms and foundation engineering in paved and unpaved roads and temporary works.

more...

Abgrid Geogrid

Terrex SNW Geotextile

The Terrex SNW geotextile range are engineered to provide unrivalled CBR puncture resistance and tensile strength offering maximum protection at optimum cost levels.

more...

Terrex SNW Geotextile
 

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