Dubai International Airport is the hub of air traffic in the Persian Gulf with nearly 90 million international passengers handled there each year. Its popularity has meant that its operators are constantly investing in capacity expansion, which led to the necessity of the recent tunnelling work.

The new pipelines will efficiently collect and drain away rainwater, especially during heavy downpours, so it can no longer accumulate on the surface. This is crucial to maintaining smooth flight operations.

The absolutely safe and precise crossing under airport taxiways and runways is one of the supreme disciplines of mechanized tunnelling - especially when flight operations cannot be interrupted. Heave, settlement or other impairment of this highly sensitive infrastructure must be avoided at all costs. Herrenknecht tunnel boring machines in the hands of skilful tunnel builders are ideally equipped for this challenging task.

The tunnelling crew from International Foundation Group, working for Dubai Aviation Engineering Projects under the project management of M.A. Kharafi & Sons, relied on Herrenknecht tunnelling technology to extend the stormwater drainage system at Dubai Airport.

Using the pipe jacking method, an AVN machine (AVND2400AB, Ø 3,025mm) mastered the challenge of three drives of 610, 765 and 825m respectively under the taxiway. The result is a new drainage tunnel with a total length of 2,200m, which increases the airport's drainage capacity.

At depths of 13 to 15m, the micromachine crossed under the Terminal 2 taxiways while flight operations on the ground and in the air continued smoothly and safely.

On the longest drive an average of 15m of tunnel per day were excavated through soft soils with sandstone and siltstone. The drive remained exactly on course by precise process and control technology from VMT.