Geotechnical and construction considerations of pile foundations in problematical soils

Abstract

The Continuous Flight Auger (CFA) technology has evolved especially in recent decades. Using of CFA technology has expanded all over the world. The article deals with geotechnical design of pile foundations, especially by static load tests and by calculation using numerical models. Results of static load tests which were performed in and in Slovakia are analysed and compared with numerical modelling. The technology of CFA has been used due to the advantages of this technology in comparison with driven and bored piles in local geotechnical conditions. Plaxis 2011 was used for CFA piles analyses by FEM. Advanced constitutive hardening soil model was used for soil layers. Comparison of load-settlement curves, ratio of pile base and pile shaft resistance and distribution of unit shaft friction are presented in the paper. The best geoengineering solution in this case is the use of new pile technology CFA (continuous flight auger), FDP (full displacement piles), DDS (drilling displacement system), that lead to increased bearing capacity.