Civil Engineering Reference
In-Depth Information
that can be transferred across any laps:
f
Lwd
;
GS
min
f
yd
;
f
Gud
;
Lw
A lap is planned on the sof
t of the beam in accordance with DAfStb guideline [1, 2]
part 1 Fig. RV 9.2. According to DAfStb guideline section RV 9.2.7.2 (RV 7),
260mm is therefore available for this lap length. The maximum length of lap that can
be counted according to DAfStb guideline part 1 Eq. (RV 6.112) is
p
p
200 000
?
6
E
Lm
?
t
L
l
u
;
max
0
:
121
?
0
:
121
?
132
:
6mm
As
l
ü,max
<
l
ü
, the stress that can be transferred at the lap is calculated according to
DAfStb guideline [1, 2] part 1 Eq. (RV 6.113):
r
200 000
6
r
E
L
t
Lw
1
004
γ
BG
?
:
1
:
004
1
:
3
?
141
:
0N
=
mm
2
f
Lwd
;
GS
The strength of a steel shear strap to be used in the calculations is therefore
min 188
;
141
g
141
:
0N
=
mm
2
f
Lwd
;
GS
min
f
yd
;
f
Gud
;
Lw
f
The additional shear force that can be accommodated can be calculated using DAfStb
guideline [1, 2] part 1 Eq. (RV 6.108):
A
Lw
s
Lw
?
z
?
f
Lwd
?
cot
V
Rd
;
Lw
θ
1
:
6
?
0
:
9
?
653
?
141
?
1
:
67
221
:
42 kN
The total load-carrying capacity of the tie is therefore given by DAfStb guideline [1, 2]
part 1 Eq. (RV 6.107):
V
Rd
V
Rd
;
s
V
Rd
;
Lw
215
:
0
221
:
4
436
:
4kN
The load-carrying capacity of the tie is now greater than the design shear force and so the
design with the shear strengthening is veri
ed.
V
Rd
436
:
4kN
V
Ed
;
red
;
s
384
:
7kN
To complete the analysis, it is only necessary to check the fasteners for the steel
which are required to anchor the shear straps in the compression zone (see
Figure 3.10).
6.6.3 Check for concrete cover separation failure
When checking for a concrete cover separation failure, it is
first necessary to calculate
the shear resistance of a member without shear reinforcement. The shear resistance of
a member without shear reinforcement is obtained from the maximum of Eqs. (6.2a)
and (6.2b) in DIN EN 1992-1-1 [20, 21]. The design shear resistance according to
Eq. (6.2a) is
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