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IBRACON Structures and Materials Journal • 2012 • vol. 5 • nº 2
Design model and recommendations of column-foundation connection through socket with rough interfaces
For both vertical and horizontal secondary reinforcements, a spac-
ing s between 150 mm and 300 mm must be adopted.
3. Model and recommendations for
the design of rough column bases
3.1 Proposed model based on monolithic behavior
Although the experimental investigation carried by Canha [4] was
focused mainly on pedestal walls, the observed monolithic behav-
ior of rough interface connections indicates that detailing of the
column base obeys the same bending theory.
As mentioned previously, based on the experimental results ob-
tained by Nunes [11], it was possible to refine the model describing
the transfer of load from the column to socket originally proposed
by Canha et al. [10].
Figure 10 – Design model proposed for the rough column base
With the model calibrated for socket foundations, the forces acting
on the column can be obtained, resulting in the proposed model
shown in Figure 10.
The rough column base is subjected to H
f
and H
r
on the sides refer-
ring to the front and rear
transverse walls, respectively, resulting
from the transfer through struts of the internal compression and
tension forces to these walls as presented in item 2.3.1.
Besides the mobilization of the friction forces, the use of shear keys
on the inner pedestal walls and column faces permits the transfer
of shear through interlock mechanical mechanism between shear
keys. The proposed model considers the shear stresses on both the
transverse and longitudinal walls as uniformly distribution. The shear
stress resulting from the action of the bending moment
(t
M
) is con-
sidered to act in the upward direction on the compression side and
downward on the tension side. Meanwhile, the shear stress mobi-
lized due to the normal force (
t
N
) has an upward direction in all walls.