Camilty Wind Farm - Partnerships for Renewables

Camilty Wind Farm
4.5 Civil Engineering Works
Wind Turbine Foundations
4.5.1 Foundation construction design will be finalised at the detailed design and engineering stage.
However, a typical foundation design is shown in Figure 4.2. The dimensions and
engineering design of the foundation will vary according to the turbine model chosen, and the
ground conditions. However, although the indicative foundation in Figure 4.2 should not be
assumed to be to scale, the diameter (maximum 21 m) and depth (maximum 6 m) shown
have been assumed within this ES as a reasonable worst case. Prior to construction,
detailed intrusive ground investigations will be undertaken at each turbine location and,
depending on the information derived from these investigations, modifications may be made
to the foundation designs.
4.5.2 Construction of the turbine foundations will generally require excavation to expose suitable
bearing strata. The depth of the excavation will depend on the depth to the suitable bearing
strata or pile cap. This will depend on peat/ soil depth on site – as discussed in Appendix
13.2, turbines will not be placed on areas of peat deeper than 3 m. Depending on the terrain,
the foundations will typically be constructed at a depth of approximately 3 to 6 m.
4.5.3 The sides will be ‘battered’ back to ensure that they remain stable during construction.
4.5.4 The excavated area will be back-filled with compacted layers of graded material from the
original excavation, and capped with soil. Around the turbines, the finished surface will be
capped with crushed aggregate to allow for safe personnel access around the base of the
turbine.
4.5.5 If appropriate, excavated material will be reused for access track construction, to supplement
locally imported rock.
4.5.6 A 5 m radius of hard standing will be laid around the turbine base, above the foundation, to
allow for vehicular access to the turbine for maintenance purposes.
Crane Pads
4.5.7 A crane pad of approximately 45 m x 25 m will be required adjacent to each turbine base to
accommodate the cranes required for construction and to provide a laydown area adjacent to
each turbine location. Figure 4.3 illustrates a typical crane hard standing area. All hard
standings will be formed with crushed rock over geotextile membranes.
4.5.8 Hard standings will be sufficiently level to ensure the safe operation of the cranes. The
turbine foundation will then be completed and backfilled as described above. The final detail
of the crane hard standing will depend on the exact specification of the cranes selected by
the contractor. A large crawler or wheeled/mobile crane will be required for turbine erection,
with one smaller pilot crane assisting with the lift procedure.
4.5.9 Crane hard standing areas will be allowed to naturally re-vegetate during operation of the
wind farm, though will not be replanted.
Site Access
4.5.10 The existing access routes, in the form of forest tracks and roads, would be upgraded within
the site and new routes to each turbine location created where necessary. Typical cross
sections across the proposed upgraded internal access tracks are illustrated in Figure 4.4.
March 2013 4-10 ES Chapter 4
Description of the Proposed Development
Copyright Partnerships for Renewables Development Co. Ltd 2013 ©