Civil Engineering Reference
In-Depth Information
Table 3.22 Categories of Bolted Connections Specified in EC3 (BS EN 1993-1-8) [2.13]
Category
Criteria
Remarks
Shear connections
A
Bearing type
F
v,Ed
F
v,Rd
F
v,Ed
F
b,Rd
No preloading required
Bolt classes from 4.6 to 10.9
can be used
B
Slip-resistant at
serviceability
F
v,Ed,ser
F
s,Rd,ser
F
v,Ed
F
v,Rd
F
v,Ed
F
b,Rd
Preloaded 8.8 or 10.9 bolts should
be used
C
Slip-resistant at
ultimate
F
v,Ed
F
s,Rd
F
v,Ed
F
b,Rd
F
v,Ed
N
net,Rd
Preloaded 8.8 or 10.9 bolts should
be used
Tension connections
D
Non-preloaded
F
t,Ed
F
t,Rd
F
t,Ed
B
p,Rd
No preloading required
Bolt classes from 4.6 to 10.9 can
be used
E
Preloaded
F
t,Ed
F
t,Rd
F
t,Ed
B
p,Rd
Preloaded 8.8 or 10.9 bolts should
be used
tensile loading. However, they may be used in connections designed to
resist normal wind loads. On the other hand, in category E (preloaded), pre-
loaded 8.8 and 10.9 bolts with controlled tightening should be used. The
design checks for these connections are also summarized in
Table 3.22
spec-
ified in EC3 (BS EN 1993-1-8) [2.13]. Bolt holes should have limiting
values for the spacing between two adjacent holes and for the distance
between a hole and an adjacent edge to avoid local failures. EC3 (BS EN
1993-1-8) [2.13] specifies the minimum and maximum spacing and end
and edge distances for bolts as given in
Table 3.23
.
Minimum and maximum
spacing and end and edge distances for structures subjected to fatigue are
The design shear resistance of bolts per shear plane can be calculated,
adopting EC3 (BS EN 1993-1-8) [2.13], as follows:
a
V
f
ub
A
g
M2
F
v
,
Rd
¼
ð
3
:
102
Þ
wherein for the shear plane that passes through the threaded portion of the
bolt (
A
is the tensile stress area of the bolt
A
s
),
a
v
¼
0.6 for classes 4.6, 5.6, and
8.8 and
a
v
¼
0.5 for classes 4.8, 5.8, 6.8, and 10.9, and for the shear plane that
passes through the unthreaded portion of the bolt (
A
is the gross cross section
of the bolt),
a
v
¼
0.6.
Search WWH ::
Custom Search