Behavior of different piles, conducted in diabasic soil, submited to uplift efforts / Estudo do comportamento a tração axial de diferentes tipos de estacas em solo de diabasio da região de Campinas/SP

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

This research presents the behavior of different kinds of piles conducted in unsaturated diabasic porous soil submitted to uplift forces. For this research there were built the follow piles: three instrumented root piles with 12m length and 410mm of nominal diameter, one root pile with nominal diameter of 310mm and 23m length, two metallic piles type W250x32.7 with 18 meters length, one metallic pile with 12m length and type W250x32.7, two trail piles TR37 type, one of them with 18 meters length and the other with 20.5 meters length. There were also considered in this research the follow piles already conducted at the studied area: three bored piles with 12 meters length and diameter of 400mm, three Continuous Flight Auger piles with 12 meters length and diameter of 400mm, one Omega pile with 12m length and diameter of 370mm and one Concrete Precast pile with 14 meter length and diameter of 180mm. The piles were built at the site for Experimental Studies in Soil Mechanics and Foundations. This experimental area is situated at the State University of Campinas, in the interior region of the state of São Paulo, Brazil. The local subsoil is basically composed by a superficial layer of approximately 6,5m thick composed of high porosity silt-sand clay followed by clayey-sandy silt. The water table is not checked until a depth of 17 meters. The carrying capacity of the studied piles was also provided by means of theoretical methods appropriate for uplift forces. The methods considered were: Method of the Trunk of Cone, Method of Cylinder of Friction, Meyerhoff (1973), Kulhawy (1985), Levacher &Sieffert (1984) and University of Grenoble in according to Martin (1963). The values estimated using the methods under consideration were compared to those obtained by means of the load tests. Methods for "load x settlement" curves extrapolation such as: Van der Veen (1953), Décourt (1998) and NBR 6.122 (1996) and Davisson (1973) were also used to provide the carrying capacity of the studied piles. There were also provided by Van der Veen (1953) and Décourt the ultimate loads for each using 50, 60, 70, 80 e 90% of the ultimate load obtained by means of the load tests. Semi-empirical methods, appropriate for compression forces, were also used considering only the portion of lateral resistance. The methods studied were the following: Décourt &Quaresma (1998); Décourt &Quaresma (1978); Aoki &Veloso (1975 - SPT); Aoki &Veloso (1975 - CPT); David Cabral (1986); P.P Velloso (1981); Teixeira (1996); Antunes &Cabral (1996); FUNDESP (1998) e Monteiro (2000). The obtained values of lateral resistance were compared to the maximum load obtained by means of the load tests. The settlements of the studied piles were also determinate by Vesic (1969, 1975a) and Poulos &Davis (1980). Mathematical correlations between lateral friction values, obtained by means of the load tests, and lateral resistance values obtained by means of field tests like SPT-T and CPT were also provided in this research

ASSUNTO(S)

resistencia a tração residual oil piles fundações (engenharia) load tests uplift efforts metodos semi-empiricos theoretical methods

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