HAC_Technical-Guide

180 181
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
7.1 & 7.2 Introduction to
Anchor Channel Design
7.3 Anchor Channel Tension Design 7.4 Anchor Channel Shear Design (y) 7.4 Anchor Channel Shear Design (X)
7.5 Interaction Equations
(Combined Loading)
7.6 Seismic Design
Steel Concrete Steel Concrete Steel Concrete
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
. Example for finding s
cr,v
is demonstrated below.
ú
ú
û
ù
ê
ê
ë
é
×
÷
÷
ø
ö
ç
ç
è
æ
-+
ú
ú
û
ù
ê
ê
ë
é
×
÷
÷
ø
ö
ç
ç
è
æ
-+
ú
ú
û
ù
ê
ê
ë
é
×
÷
÷
ø
ö
ç
ç
è
æ
-+
=
1
2
1.5
Vcr,
4
1
2
1.5
Vcr,
3
1
2
1.5
Vcr,
2
v,1s,
V
V
s
s
1
V
V
s
s
1
V
V
s
s
11
1
y
Figure 7.4.2.5 — Example of an anchor channel with different anchor shear forces.
ψ
co,V
: The modification factor for corner effect for an anchor
loaded in shear perpendicular to the channel, shall be
computed in accordance with Eq. (34) or (35).
If c
a2
≥ c
cr,V
then ψ
co,V
= 1.0 ESR-3520 Equation (34)
If c
a2
< c
cr,V
then ψ
co,V
= (c
a2
/c
cr,V
)
0.5
ESR-3520 Equation (35)
where:
c
cr,V
= 0.5 · s
cr,V
= 2c
al
+ b
ch
in. (mm) ESR-3520 Equation (36)
If an anchor is influenced by two corners (as shown in Figure
e), then the factor ψ
co,V
shall be computed for each corner in
accordance with Eq. (34) or (35) and the product of the values of
ψ
co,V
shall be inserted in Eq. (30).
Figure 7.4.2.6 — Example of an anchor channel loaded in shear with anchors a)
influenced by one corner and b) influenced by two corners.
ψ
c,V
: The modification factor for cracked/uncracked
concrete.
Cracked concrete conditions with no supplementary
reinforcement → ψ
c,V
= 1.0
Note: if cracked concrete conditions are assumed, and
supplementary edge reinforcement as defined in ESR-3520
Section 4.1.3.3.3 is used, ψ
c,V
can be increased to either
ψ
c,V
= 1.2 or ψ
c,V
= 1.4.
Cracked concrete ψ
c,V
= 1.0
No supplementary reinforcement
With supplementary reinforcement
• Cracked concrete with edge reinforcement (#4 min.)
ψ
c,V
= 1.2
• Cracked concrete with edge reinforcement (#4 min.) and
stirrups (#4 min.) spaced at 4” O.C.
ψ
c,N
= 1.4
Uncracked Concrete ψ
c,V
= 1.4
Anchor channels located in a region of a concrete member
where analysis indicates no cracking at service load levels.
Note: in order to activate the reinforcement, concrete has
to crack. Therefore, if uncracked concrete is assumed,
supplementary reinforcement does not impact this factor.
Concrete is typically assumed to be cracked under normal
service load conditions. If cracked concrete conditions are
assumed, an increase in V
cb,y
is permitted via the modification
factor ψ
c,V
if supplementary edge reinforcement is used. If
uncracked concrete conditions are assumed, an increase in V
cb,y
is likewise permitted via the modification factor ψ
c,V
. Reference
ESR-3520 Section 4.1.3.3.3 for more information.
ψ
h,V
: The modification factor for member thickness.
The modification factor for anchor channels located in a
concrete member with h < h
cr,V
, ψ
cr,V
(an example is given in
Figure 7.4.2.7), shall be computed in accordance with Eq. (37).
c
a1
is measured perpendicular to the anchor channel longitudinal
axis, and is considered when calculating the basic concrete
breakout strength in shear (V
b
) and the modification factor for
member thickness (ψ
h,V
).
h
ch
… height of anchor channel
β
1
... Given in ICC-ESR alternatively a default value of 0.50 shall
be used
h
cr,V
… critical member thickness
h
cr,V
= 2c
a1
+ 2h
ch
ESR-3520 Equation (38)
1.0
h
h
1
Vcr,
Vh,
£
÷
÷
ø
ö
ç
ç
è
æ
=
b
y
ESR-3520 Equation (37)
Figure 7.4.2.7 — Example of an anchor channel in a member with a
thickness h < h
cr,V
Anchor channel influenced by two corners and member
thickness (c
a1,red
)
Where an anchor channel is located in a narrow member
(c
a2,max
< c
cr,V
) with a thickness h < h
cr,V
(see Figure 7.4.2.8), the
edge distance c
a1
in Eq. (31), (33), (36) and (38) shall not exceed
the value c
a1,red
determined in accordance with Eq. (39).
2,max
1,
2
max , , . ( )
22
a ch
ch
a red
cb
hh
c in mm
-
æö
-
=
ç÷
èø
ESR-3520 Equation (39)
where c
a2,max
is the largest of the edge distances perpendicular
to the longitudinal axis of the channel. For this example, the
value of c
a1,red
is obtained by moving the failure surface forward
until it intersects the corner as shown.
Figure 7.4.2.8 — Example of an anchor channel influenced by two corners
and member thickness (in this example c
a2,2
is decisive for the determination
of c
a1,red
)