Soiling Stabilisation
 

Soiling Stabilisation


Soil stabilisation refers to the process of changing soil properties to improve strength and durability. The Coffey Group use many techniques for soil stabilisation, including rock anchors, soil nailing, sheet piling, injection technology and rock fall netting.

Coffey Experience :


Rock Anchors

Embankment Stabilisation - Sorrento Mews, Dalkey, Co. Dublin
Client: Irish Rail
Project Value: £202,000 (ex VAT)

Project Description:

Emergency Works

Following heavy rain during the run up the Christmas the retaining wall began to slip by a distance of 75mm. A decision was made to remove the wall under emergency works before the inevitable collapse would have caused a major H & S risk to the public. The works involved:

  • Establishment/reporting of monitoring regime.
  • Removal of shrubs & trees on over working platform area.
  • Installation of working platform & guard rail/safety barrier.
  • Rock anchors (sixty two R32/R40 hollow bars 8m long).
  • Casting of RC wall to flower bed level.
  • Installation of concrete anchor blocks and soil nail assemblies to new RC wall.
  • Removal of existing RC capping beam and lowering of existing stone wall.
  • Completion of RC wall and casting of RC capping beam.


 

            

 

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                              Existing Wall                                                                                             Wall Partially Demolished   

Alternative Design

Coffey Construction proposed an alternative design by the use of pre-cast panels in lieu of pouring concrete in-situ. The panels proposed were the product from Oran-Precast. These consisted of two 65mm panels spaced apart by chairs all which was cast in factory conditions.

Installation of Soil Nails

Coffey Construction carried out all the specialist works drilling, grouting and testing, along with the placement of the precast panels and stone facing.

 

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Testing

The lower line of soil nails was tested to a tensile load of 320kN and the upper row was tested to a force of 230kN. As per the specification one fifth of the total number of anchors was tested and all passed. The tolerance was a maximum displacement of 19mm and all tests carried out on site were within the range of 7-12mm.



Stone Cladding

Architectural stone cladding







Soil Nailing

Embankment Stabilisation Fontenoy, Co. Wicklow
Client: Irish Rail
Project Value: £41,000 (ex VAT)


Project Description:


The project consisted of the installation of fifteen soil nails to stabilise both an existing retaining wall and the support embankment beneath it. The soil nails installed were R32mm diameter and 4m in length. All were grouted into position and tested. All works were carried out during night time possessions. The embankment soil nails was installed and a 30kN geogrid erosion protection layer was installed in the affected area.





Sheet Piling

Manulla Embankment Stabilisation Works, Mayo
Client: Irish Rail
Project Value: £285,000 (ex VAT)

Project Description:

An embankment section of the Westport to Dublin line in Manulla was under distress due to the existing steep embankment 1:1. The section of track was on a long curve and stabilisation of this embankment was required. The project consisted of the installation, as permanent works, a line of sheet piles each side of the embankment to stabilise it. The works consisted of the following:

  • 199m of 11m long PU 12 sheet piles.
  • Tie-bar installation @ 5m intervals to tie each sheet pile together.
  • Trimming of all piles to the required levels.
  • Filling of granular material between existing embankment and new sheet piles.



 



Soil Stabilisation

Soil Stabilisation Works - Birr, Co. Offaly
Client: Bord na Mona
Project Value: £65,000 (ex VAT)

Project Description:

The works involved the construction of an access road through a peat land area. The option of ‘Dig & Replace’ was not allowed due to planning restrictions. A 350m long 5m wide access road was constructed by means of stabilisation of existing soil to establish a sufficient axial ground bearing pressure for works vehicles.

 

 

Injection Technology

Soil Stabilisation Works Client: Coffey Homes Ltd
Project Value: £64,000 (ex VAT)

Project Description:

The project consisted of the remediation of the gable end of a listed structure which formed part of an old water mill in Galway. The works involved the injection of a cementious grout especially designed for masonry structures. Once injected the crack was pointed using NHL5 lime mortar.


 

Rock - Fall Netting

Soil Stabilisation Works
Client: Coffey Homes Ltd
Project Value: £64,000 (ex VAT)

Project Description:

The project consisted of the remediation of the gable end of a listed structure which formed part of an old water mill in Galway. The works involved the injection of a cementious grout especially designed for masonry structures. Once injected the crack was pointed using NHL5 lime mortar.


 


Coffey Group, Athenry, Co. Galway, Ireland Tel: +353 91 844356 Fax: +353 91 844519 Email: info@coffeygroup.com