Artificial Ground Freezing: A Smart Application Below the Airport of Perth-Video

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Video Summary

Trevi and GFWA used artificial ground freezing for three cross-passages on Perth’s Forrestfield–Airport Link, a rail project connecting the eastern suburbs and airport to the city network. Because the passages lay beneath an operational airport taxiway, drilling had to be carried out from inside the tunnels. Ground conditions included water-bearing sand and gravel, with groundwater pressure around two bar.<br /><br />Detailed soil testing and thermal and structural analyses informed the freezing-pipe layout, accounting for restricted drilling zones, tunnel joints and a large temporary steel structure. The design required a frozen soil body at an average temperature of −10°C, while limiting frost heave to 1.5 cm. Two electric drilling machines installed about 300 pipes; deviation averaged 1%, with only two clashes.<br /><br />Chillers and extensive temperature, pressure and ground monitoring supported the freezing and maintenance phases. Data was shared with project stakeholders every 30 minutes. Despite technical challenges, the frozen ground performed as designed, and the cross-passages were successfully completed.

Keywords

artificial ground freezing

Forrestfield-Airport Link

cross-passages

groundwater pressure

frost heave