George Best Belfast City Airport – Various Projects

George Best Belfast City Airport (“GBBCA”), formerly known as ‘Belfast City Airport’, is a single-runway airport in Belfast adjacent to the Port of Belfast and just 3 miles from Belfast city centre. The airport began commercial operations in 1983 and is consistently in the top five busiest airports on the island of Ireland each year, regularly handling well in excess of 2 million passengers.

Doran Consulting has a long-standing relationship with GBBCA and has provided a range of structural and civil engineering advice in relation to a number of commissions over the years involving various extension, improvement and upgrade works on the airport:

Front of Terminal Protection – Hostile Vehicle Mitigation Works

Doran Consulting provided civil design advice and contract administration for this scheme to establish a 30m exclusion zone around the main terminal entrance, which was achieved with the construction of a 170m long proprietary reinforced earth berm (raised barrier) system at the front of the terminal building.

Staged gaps, controlled with both static and removable bollards, were left in the berm to allow maintenance and emergency vehicle access. Both the berm and bollards were designed to comply with PAS 68 security classification, being able to withstand impact from vehicles up to 7.5 tonnes in weight travelling at up to 50mph.

The scheme also required the provision of a dedicated taxi and bus drop off zone with controlled access, a passenger footway and sheltered waiting areas beyond the new exclusion zone, and relocation of the existing executive car park. Extensive vehicle autotracking was carried out to ensure that the existing traffic circulation philosophy was not compromised. As part of the works, an existing roundabout was widened to accommodate the turning movements of coaches and other large vehicles.

The berm itself was also landscaped as part of the project with topsoil and grass to create a ‘soft’ appearance, and the ends were capped with decorative walls. A new hedge and chestnut paling fence were installed along the pre-existing and new roads in front of the terminal building to discourage passenger drop-off or pick-up in undesignated areas. New hard standing areas consisting predominantly of hot-rolled asphalt and incorporating a new surface water drainage system were also added. The road formations incorporated large stone capping layers and geogrid technology to protect against differential settlement in areas of particularly poor ground conditions.

New Airbus Stand 24 & Associated Works

Doran Consulting was appointed to consider locations for a new aircraft stand which would accommodate an A321 Airbus, a large medium-range aircraft. We provided a number of site options, including existing hardstandings, and identified potential locations for new hardstandings. The final site as chosen by the client was an existing area of hardstanding which required the construction of a new pavement when investigations concluded that the area’s Pavement Classification Number (“PCN”) was too low for the intended purpose.

Very soft clays beneath the new pavement meant that a subgrade improvement layer was also designed and added, utilising layers of stone and geogrid to spread the expected loads and control settlement. The use of a stone mastic asphalt surface course and dense bitumen macadam base course reduced cost and accelerated the construction process.

An extremely tight deadline of 6 weeks for completion was in place and in this time, we successfully managed the appointment of subcontractors and resolved a complicating factor which was the presence of a critical 1,000m diameter NI Water pumping main serving East Belfast which was located directly under the footprint of the new area. We liaised with NI Water to establish safe systems of work and ensured the works on the stand did not affect the normal daily operations of the airport.

Necessary additional works on the project included the realignment of landside roads and the RZ fence, drainage amendments, stand lighting, provision of CCTV, stand and apron markings. The entire project was completed on time, within budget and with no disruption to the planned arrival of the first aircraft.

UK Borders Agency Accommodation

Doran Consulting provided civil, structural and environmental design services as part of a Design & Build Team for the UK Borders Agency accommodation facility at GBBCA. The project presented a number of challenges including very poor ground conditions, elevated methane gas levels in the ground and the close proximity to the existing buildings.

We led the environmental team who carried out the Risk Assessments which identified the risk of ground gases and subsequently the intrusive study to actively monitor the gas levels. We then prepared reports on the Environmental Assessment which were submitted to the Planning Service to inform the planning application process.

We had to work closely with the client during the works to ensure all stands were able to operate as normal and access along the airside corridor and to the external sections of baggage carousels were maintained.

Apron Drainage Investigations & Remedial Works

We were commissioned to undertake drainage investigations of areas of existing apron which experienced repeated flooding during heavy rainfalls. We organised and supervised topographical, drainage and CCTV surveys, analysed the results and made recommendations for remedial works. We were subsequently commissioned to provide detailed design advice for the remedial works.