MONA OFFSHORE WIND FARM - PHASE 2

CJ Associates (CJA) were instructed by Jera Nex bp (Client) under the technical direction of Wardell Armstrong to deliver a Ground Investigation (GI) to support the design of a new underground electricity cable route and Land Substation between Abergele and Bodelwyddan in Denbighshire, North Wales. The aim of the scheme was to connect new offshore wind capacity to the electricity transmission network.

Phase 2 of the project followed on from a previous investigation campaign which saw fieldworks suspended over winter months in order to avoid the poorest ground conditions and inclement weather. Prior to mobilisation, a pre-works site visit was undertaken by a representative from CJA to meet with various stakeholders and plan the works.

An 11-week fieldwork programme was undertaken, commencing with a rotary rig lift carried out under traffic management provided by an approved subcontractor during a weekend night shift, for a location situated on the A55 dual carriageway near Abergele.

Three rotary rigs and crews from both Central Alliance and CJA were employed to complete 34nr rotary boreholes to a maximum depth of 23mbgl with combined gas and water monitoring instrumentation installed for subsequent monitoring.

29nr trial pits and associated in-situ soakaway testing was completed together with 13nr Cone Penetration Tests (CPTs) to determine equivalent thermal resistivity information.

Up to 4 simultaneous work fronts were operational at any one time, supported by a team of geo-environmental engineers and a lead Site Agent to co-ordinate fieldworks. The project was administered by a leadership team of project managers and support staff to provide timely submission of deliverables in accordance with the specification.

On completion of fieldworks a programme of monitoring was undertaken as well as associated geotechnical / geoenvironmental laboratory testing and factual reporting services.

“The collaborative spirit and dedication demonstrated by your team are commendable and highly valued. We look forward to continuing our successful collaboration in future endeavours.”                                   – Jera Nex bp Site Investigation Project Manager