Execucao de estaca

FRANKI AFRICA - PILED FOUNDATIONS
Continuous Flight Auger (CFA) Piles – estacas moldadas executados com trado contínuo Continuous Flight Auger (CFA) Pile Installation Sequence | | | | | A. The hollow-stemmed Continuous Flight Auger is drilled into the ground by means of the drive-head. Penetration of the auger into the ground is slower than the combination of pitch and rotation, so a certain amount of soil is ejected at the surface. This decompression is necessary to allow penetration of the auger. B. The auger is drilled down to the founding level after which the concrete / grout pump is connected to the hollow-stemmed flight by means of high pressure hoses. C. The concrete / grout is pumped down the hollow-stemmed flight as the latter is gradually withdrawn. A high level of control is necessary to ensure that the rate of extraction matches the rate of flow of the concrete / grout. If the extraction rate is too fast, a necked pile shaft will be formed. If it is too slow, there will be a pressure build-up which forces grout up the sides of the auger, and can lead to the flight becoming stuck. D. The steel reinforcing cage is lowered into the wet concrete / grout in the pile shaft until it is at the correct level. This completes the installation sequence. | |

http://www.franki.co.za/content/index.cfm?navID=1&itemID=91

http://www.fhwa.dot.gov/engineering/geotech/foundations/auger.cfm

FRANKI - Geotechnical Investigation

http://www.esorfranki.co.za/civil-engineering-earthworks-pipeline-construction/franki-africa/geotechnical-investigation.html

http://www.franki.co.za/content/index.cfm?navID=5&itemID=20

PILES http://theconstructor.org/geotechnical/pile-instalation-methods/1812/ NEED AND FUNCTION OF PILE