Project Description

Malachy Walsh and Partners acted as civil/structural designer for Moriarty Civil Engineering Ltd at Monaincha. The project consists of the construction of 15 turbines numbered T1 to T12 and T14 to T15.

Malachy Walsh and Partners completed a risk assessment report for the entire project including roads infrastructure, turbine bases/hardstands. That report identified the main design risks, construction of heavy civil engineering works in ground conditions comprising up to 20m of very soft silts and peat, along with general wind farm project risks.

The employer’s requirements and tender documents supplied to Moriartys included some SI information. MWP interpreted those reports and used them in developing the design for the turbine foundations and other infrastructural components of the wind farm. MWP procured additional SI information which is outlined below.

The WTG foundations were designed for a Nordex N117 turbine with 91m hub height and 117m rotor diameter. A finite element analysis of the turbine foundations was completed using STRAP Version 2011. Spring supports were used to model the lateral restraint provided by the concrete piles. The FE model is similar to that shown below, consisting of radial and concentric distribution of elements to create a representation of the turbine base in question.  Bases are circular in shape with a central pedestal containing the holding down bolts.  Bolt lengths for Nordex WTGs have an overall length of 3.045m.