HAC_Technical-Guide

406 407
Cast-In Anchor Channel Product Guide, Edition 1 • 02/2019
1. Anchor
Channel Systems
2. HAC
Portfolio
3. HAC
Applications
4. Design
Introduction
5. Base material 6. Loading
7. Anchor Channel
Design Code
8. Reinforcing
Bar Anchorage
9. Special Anchor
Channel Design
10. Design
Software
11. Best
Practices
12. Instructions
for Use
13. Field Fixes
14. Design
Example
Code Discussion Calculations
Step 7: Concrete strength
ESR-3520 Section
4.1.3.3.4.
ACI 318-14 Chapter 17
Concrete breakout strength in perpendicular shear for anchor element #3 continued...
The value calculated for concrete breakout strength in shear (V
cb
) is based on the
location of the anchor element being considered. The basic concrete breakout
strength in shear (V
b
) is not dependent on the anchor element being considered, but it
is dependent on the concrete geometry via the parameter c
a1
. However, the calculated
value for V
b
will be the same for each anchor element if the c
a1
value is the same for
each element.
The parameter ψ
s,
V will be dependent on the anchor element being considered and
the concrete geometry. Reference ESR-3520 Equation (32) for more information on
how to calculate ψ
s,V
.
The parameter s
cr,V
corresponds to the maximum distance that is assumed with
respect to the influence of an anchor element on the anchor element being
considered. Any anchor elements that are within s
cr,V
from the anchor element being
considered are assumed to have an influence on that anchor element. The calculated
value for s
cr,V
will be the same for each anchor element if the c
a1
value is the same for
each element; however, the number of anchor elements within the distance s
cr,V
from
the anchor element being considered may not always be the same. Reference
ESR-3520 Equation (33) for more information on how to calculate s
cr,V
.
Calculate the modification factor for anchor influence (ψ
s,V,3
).
ESR-3520 Equation (32)
å
+
=
ú
ú
û
ù
ê
ê
ë
é
×
÷
÷
ø
ö
ç
ç
è
æ
-+
=
1n
2i
3
a
ua,
i
a
ua,
1.5
Vcr,
i
V,3s,
V
V
s
s
11
1
y
s
i
= spacing between each anchor element = 5.91 in
s
xx,1
= distance of each influencing anchor element from anchor element #3
s
1,3
= distance from anchor element #1 to anchor element #3 = 11.82 in
s
2,3
= distance from anchor element #2 to anchor element #3 = 5.91 in
s
cr,V
= critical anchor spacing for shear loading
c
a1
= 4.50 in
b
ch
= 1.65 in (reference ESR-3520 Table 8-1)
s
cr,V
= 4
ca1
+ 2b
ch
ESR-3520 Equation (33)
V
a ua,1
= shear load on anchor element #1 = 422 lb
V
a ua,2
= shear load on anchor element #2 = 1464 lb
V
a ua,3
= shear load on anchor element #3 = 1615 lb
Concrete edge breakout: ФV
cb,y
s
cr,N
= 4 x 5 in + 2 x 1.65 in
s
cr,N
= 23.3 in
influence of anchor element #1 on anchor
element #3:
1.5
11.812 421
1
23.30 1618
0.0901
in lbs
in lbs
æö
-
ç÷
èø
=
influence of anchor element #2 on anchor
element #3:
1.5
5.906 1461
1
23.3 1618
0.582
in lbs
in lbs
æö
-
ç÷
èø
=
, ,3
, ,3
1
1 (0.0901 0.582)
0.598
sV
sV
y
y
=
++
=
Figure 14.1.22 — Design example – spacing reduction factor of ψ
s,v
Code Discussion Calculations
Step 7: Concrete strength
ESR-3520 section
4.1.3.3.3
ACI 318-14 Chapter 17
Concrete breakout strength in perpendicular shear
for anchor element #3 continued...
Calculate the modification factor for corner influence (ψ
co,V,3
).
1.0
c
c
0.5
Vcr,
a2
Vco,
£
÷
÷
ø
ö
ç
ç
è
æ
= y
ESR-3520 Equation (35)
cha1Vcr,Vcr,
b2cs0.5c +=×=
ESR-3520 Equation (36)
c
a2
… corner distance of the anchor under consideration
c
cr,V
…critical edge distance for anchor channel for shear loading
The parameters c
a1
and c
a2
correspond to the distance from the center of the anchor
element being considered to a fixed edge. c
a2
is measured parallel to the anchor
channel longitudinal axis, and is considered when calculating the modification factor
for corner influence (ψ
co,v
). When concrete breakout in shear (V
cb,y,3
) is being calculated
for anchor element #3. It is important to note that values for c
a1
and c
a2
must be
considered with respect to the relevant edge distances from anchor element #3.
The parameter c
cr,V
corresponds to the maximum distance that is assumed with
respect to the value for c
a2
. Any c
a2
value less than c
cr,V
must be considered when
calculating ψ
co,V
. If more than one c
a2
value is less than c
cr,V
, ψ
co,V
will be calculated
for each c
a2
value, and the product of these ψ
co,V
values will be used to calculate the
nominal concrete breakout strength in shear (V
cb,y
).
Concrete edge breakout: ФV
cb,y
c
cr,V
= 2 (5 in) + 1.65 in
c
cr,V
= 11.65 in
774.0
774.0
11.65in
6.984in
Vco1,
0.5
Vco1,
=\
=
÷
ø
ö
ç
è
æ
=
y
y
00.1
1.0
9.61in
in
Vco2,
0.5
Vco2,
=\
>
÷
÷
ø
ö
ç
ç
è
æ
¥
=
y
y
Figure 14.1.23 — Design example – corner reduction factor of ψ
cr,v
s,v,3
1.5 1.5
s,v,3
1
11.812in 421lbs 5.906in 1461lbs
11 1
23.30in 1618lbs 23.30in 1618lbs
0.598
y
y
=
é ùé ù
æ ö æö
+ -×+ -×
ê úê ú
ç ÷ ç÷
è ø èø
ê úê ú
ë ûë û
\ =
å