Behavior of continuous flight auger piles subjected to uplift loads tests in unsaturated diabasic soil

Abstract

This paper presents the behavior of three continuous flight auger piles conducted in unsaturated diabasic soil submitted to uplift forces. The piles were built at the site for Experimental Studies of Soil Mechanics and Foundations at Unicamp situated in the city of Campinas, Brazil. Field tests have already been conducted at the site (SPT, CPT, DMT and PMT), as well as laboratory tests using sample soils taken from a well up to 17m deep. The water table is not checked until a depth of 17. In order to check the behavior of the piles when submitted to uplift forces, slow static load tests were carried out as per the recommendations of NBR 12.131/92. The carrying capacity of these piles was also provided by means of theoretical methods, appropriate for uplift forces, and through semi-empirical methods appropriate to compression forces, considering only the portion of lateral resistance. The values estimated by the methods considered were compared to those obtained by means of the load tests.