Chicago O’Hare GRE Relocation

The airport is currently undergoing a vast modernisation program, with the development of a further runway and associated support taxi-way infrastructure.

The design layout meant that a support taxi-way was required to pass directly through the positioning of their existing Ground Running Enclosure, which would need to be replaced, or, as recently carried out – ‘moved’!

IAC Acoustics Company UK Ltd, working via our US partners Blastwall won the contract with the main US civil contractors, FHPaschen, to provide engineering consultation on the relocation of the existing GRE, including assessment of the existing structure, design of new foundations, the design and supply of a new internal Jet Blastiac Fence, acoustic control room and access doors; and acoustic assessment of the GRE acoustics to confirm that the facility performance is not compromised by the relocation.

With very little original design information available, an engineering assessment was made on the current facility and foundation to allow equivalent foundations and structural anchor designs to be conservatively calculated for construction. This task was completed by AKS Ward, a UK civil and structural engineering consultants and regular construction consulting partner of IAC.

The facility downtime was an important factor in the relocation, with a 120 day shutdown period limitation, as a result of which, a specialist structural company, Claussen Structures, was appointed by FHPaschen to carry out the physical relocation, using some very specialist, bespoke moving equipment. The unique skills and processes used allowed the entire main wall structure of facility to be moved and fixed to the newly prepared foundation in 12 parts, each in the region of 40 ft square, and all within a 3 week timeframe.

The new Jet Blast Fence, designed by IAC was one of the standard range IAC Jet Blast Fences, which was aerodynamically modelled as part of the proving process to ensure compatibility with the existing GRE geometry and operating envelope. The 6m high curved solid barrier was installed across the width of the rear wall of the GRE facility to deflect the aircraft jet blast.

A new acoustic control room, again designed by IAC UK, was provided to create a quiet, safe area to view the ground run tests and house the main electrical distribution for the facility. New GRE emergency access doors were also provided to replace the broken and in one case, missing doors from the old facility. Both of these components were fabricated and installed by IAC Acoustics from their location in Arora, Illinois.