Design
D - 36
Notes‚
1.The above table shows the short term allowable pull out load for
foundation bolts when embedded for the length shown in the
above table.
2.The concrete design characteristic strength is taken to be
FC=17.6N/mm
2
.
3.When the dimensions differ from the above diagram, or if the
concrete design characteristic strength differs, then the pull out
load may be calculated in accordance with the formulae for bolts
on a strong foundation, on the left. However, the allowable pull
out strength of one bolt may not exceed 11,760N
4.Do not use bolts with an embedded length less than those shown
in the right column.
5.If type 1 or type 2 lightweight concrete is used, allow 10% margin.
The short term allowable pull out load of a bolt is obtained from the
following formula. However, if the shear stress in the bolt exceeds
44.1N/mm
2
(for SS400), bolt strength verification must be carried out,
and verification that the allowable tensile stresses are not exceeded
must also be carried out.
Here,
Ta: Foundation bolt short term allowable pull out load (N)
L: Foundation bolt embedded length (mm)
(can be taken to be the depth of the drilled hole)
P: Correction factor for concrete design characteristic strength
Fc:Cconcrete design characteristic strength (N/mm
2
)
(Normally taken to be 17.6N/mm2)
For bolts positioned near the corner or edge of the foundation, if the
distance from the center of the bolt to the edge is C L, then the bolt
allowable short term pull out load is given by formula (b) below.
Here,
C : Distance from the center of the foundation bolt to the edge of the
foundation (mm)
However,
C 4d
Note
1. If type 1 or type 2 lightweight concrete is used, allow 10% margin.
Installation location: a) Solid foundations b) Upper surface of normal floor slab c) Bottom surface of normal ceiling slab, concrete wall surface
Notes‚
1.The above table shows the short term allowable pull out load for
foundation bolts when embedded for the length shown in the
above table.
2.The concrete design characteristic strength is taken to be
FC=17.6N/mm
2
.
3.When the dimensions differ from the above diagram, or if the
concrete design characteristic strength differs, then the pull out
load may be calculated in accordance with the formulae for bolts
on a strong foundation, on the left, and divide the result by 1.5 to
obtain the allowable pull out load. However, for foundation bolts
provided in the bottom surface of ceiling slabs and on the surface
of the concrete walls, the allowable pull out load may not exceed
7,840N per bolt.
4.Do not use bolts with an embedded length less than those shown
in the right column.
5.It is necessary to investigate the short term pull out strength of
normal supports due to an earthquake provided in the bottom
surface of ceiling slabs and on concrete walls for supporting heavy
objects. For this short term pull out load, see Item b) short term
pull out loads.
6.If type 1 or type 2 lightweight concrete is used, allow 10% margin.
Ta=6
π
.
L
2
.
p
Ta=6
π
.
C
2
.
p
P= Min , 0.49 +
6
1
30
Fc
100
Fc
(7)
Allowable pull out load for post-installed screw-type mechanical foundation bolts
Short term pull out load (N) Long term allowable pull out load (N)
Mortar finish
..(a)
..(b)
7. Center of gravity position and earthquake resistant design
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