Einsatz und Anwendungsgrenzen von Schneckenbohrpfählen (Auger-cast-in-place Piles - ACIP-Piles)

Application and limitation of auger-cast-in-place (ACIP-) Piles - Experiences of an industrial project in Iowa/USA

For an industrial complex in Port Neal/Iowa, auger-cast-in-place piles (ACIP-Piles) haven been chosen for the foundation structure. With reference to the purely graded sand deposits, which have been encountered to greater depth in conjunction with a high ground water level, the installation of such piles has to be critically expected with reference to DIN EN 1536. However, the installation technique as well as acceptable pile capacities could be verified in the course of extensive pile testing. Nevertheless, considerable damages occured during the installation of the working piles. The damages can partly be attributed to an interlayered very stiff to hard cohesive soil layer at a depth of app. 20 m, which couldn't be smoothly drilled and which led to a soil extraction in the vicinity of the pile shaft. Moreover, a new drilling company was commissioned for the installation of the working piles, whose specific experience with the chosen pile type was not directly verified before. Finally, the damages were benefit by the chosen drilling technique.