Important developments have occurred in Sydney, Australia over the past few years, in preparation for the year 2000 Olympic games. The extension of Sydney International Airport was one of these key projects. Vibro-pile (Aust) Pty Ltd was awarded the multi-million dollar contract for the design and construction of the foundation of this project. The soil conditions posed considerable problems for foundations in this area, as they comprise soils ranging from soft clays to dense sands, overlying variably weathered rock at depths in excess of 35m. Continuous Flight Auger (CFA) piles provided a most cost-effective foundation solution, with 532 piles being installed ranging in diameter from 600mm to 900mm and founded at depths of up to 37m. A small number of reinforced concrete injected screw (Omega) piles were also used. The CFA piling system eliminated the disturbance of the high-density underground services and minimised the noise and vibration levels enabling normal airport operations to continue during construction. The design, construction and the quality control measures adopted are discussed. A detailed pile testing programme, incorporating static and dynamic loading tests is presented and compared with the static design. Each piling rig was equipped with computerised monitoring equipment, the output of which was reviewed by the design engineers to ensure compliance with design requirements. The computerised monitoring ensured that a high level of quality control was maintained for construction of the piles.
As part of the Airport 2000 development, extensive upgrading of the Sydney International Airport has been scheduled. In view of the sandstone bedrock, underlying greater than 32 m of Quaternary alluvial deposits, provided an ideal founding medium forcast insitu piles. Vibropile proposed CFA piles, which were accepted on the basis of cost and prod1uction considerations. The design geotechnical capacity of these piles range from 2000 kN to 4000 kN.
