Page 101 - Riem-Vol6_nº3

446 IBRACON Structures and Materials Journal • 2013 • vol. 6 • nº 3
Numerical analysis of two pile caps with sockets embedded, subject the eccentric compression load
one with small height piles. In the model was used one pile cap on
two piles with angle of inclination of the strut equal to 45º. The length
of the piles was determined according to the result of the survey
executed by Geotechnical Department, in Campus I of USP in São
Carlos. Thus, the length calculated of the piles shaft was equal to 9.0
m. Figure [19] shows the result of the survey the percussion (S.P.T.)
and Figure [20] the pile caps numerically analyzed.
The friction between the pile and the soil was not taken into ac-
count. For the existing soil around the pile shaft, we adopted a
plastic behavior (rupture criterion Drucker-Prager). The result of
the survey the percussion and mechanical properties of the soil
were obtained in Senna Júnior [18]. The force was applied through
one hundred steps, admitting it centered. In the models where
there was no contribution of the soil (Pile caps A and B – Figure
[20], it applied force until the pile cap rupture. In the other models,
the action applied corresponded to the piles loading capacity, i.e.,
600 kN.
In the soil modeling, we used the model of elastic Continuum
model (Soil 1, 4 and 5 – Figure [20]). The soil could be modeled
using Winkler hypotheses (contact pressures are proportional to
settlements), however, according to Velloso [19], the Medium Con-
tinuum model represents with higher accuracy the phenomenon of
the interaction soil-structure.
To avoid localized disturbance stress on the force application point,
it was modeled a steel plate on the head of the column five cen-
timeters thick and elastic and linear material, the same for all the
numerical analysis developed.
Figure 20 – Pile caps analyzed actual length
of the pile
Pile Cap A Pile Cap B Pile Cap C Pile Cap D
55 117,5 55 117,5 55 117,5 117,5 55
35
Soil 1
Soil 2
Soil 3
Soil 4
Soil 5
-9 m
-18 m
-22,5 m
0 m
Figure 21 – Flow principal stress compression,
Pile cap A
Figure 22 – Flow principal stress compression,
Pile cap B
Figure 23 – Flow principal stress compression,
Pile cap C