1. Anchor
Channel Systems
2. HAC
Portfolio
3. HAC
Applications
6. Loading
The nominal pryout strength, V cp,x , in shear of a single anchor
of an anchor channel without anchor reinforcement shall be
computed in accordance with ESR 3520 Eq. (41).
N cb = N b × ψ s, N × ψ ed, N × ψ co, N × ψ c, N × ψ cp, N
7.5 INTERACTION
EQUATIONS:
b) At the point of load application:
a
b
b
æ N ua
ö æ V ua , y
+
ç
÷ ç ç
è f N sl ø è f V sl , y
æ M u , flex
ç ç
è f M s , flex
2
ö
÷ ÷ £ 1.0 ESR-3520 Equation (46)
ø
α = 2 for anchor channels with V sl,y ≤ N s,l
α = 1 for anchor channels with V sl,y > N s,l
If forces act in more than one direction, the combination
of loads has to be verified. Anchor channels subjected to
combined tension and shear loads shall be designed to satisfy
the following requirements by distinguishing between steel
failure of the channel bolt, steel failure modes of the channel
and concrete failure modes. Interaction equations for each
anchor channel element are required. Moreover, concrete and
steel utilizations need not to be combined. The verification of up
to 5 interaction equations are required.
Steel Failure of Channel Bolts Under Combined Loads
2
2
æ N b ua ö æ V b ua ö
ç ç
÷ ÷ + ç ç
÷ ÷ £ 1 . 0
è f N ss ø è f V ss ø
V
b
ua
[ (
= V
b
ua, y
) + ( V
2
b
ua, x
ESR-3520 Equation (43)
) ]
This verification is not required in case of shear load with lever
arm as Eq. (28) accounts for the interaction.
Steel Failure Modes of Anchor Channels Under Combined
Loads:
Interaction equations based on Acceptance Criteria 232,
February 2019. ICC ESR-3520 to be updated.
Concrete failure modes of anchor channels under combined
loads:
Concrete Failure Modes of Anchor Channels Under
Combined Loads:
For concrete failure modes, anchor channels shall be designed
to satisfy the requirements given in a) through d). D.7.4.3,
Section D.7.4.3 (ACI 318-14) :
Section D.7.4.3.1, Section 17.6.4.3.1 (ACI 318-14) through
D.7.4.3.3, Section 17.6.4.3.3 (ACI 318-14).
Requirements for lightweight concrete: æ V ua a , y V ua a , y
æ N a N a ö
max ç ua , ua ÷ + max ç
,
ç f V sa , y f V sc , y
è f N sa f N sc ø
è
a
ö
æ V ua a , x V ua a , x
,
÷ ÷ + max ç ç
è f V sa , x f V sc , x
ø
2
ö
÷ ÷ £ 1.0
ø
ESR-3520 Equation (44)
where:
α = 2 for anchor channels with max (V sa,y ; V sc,y ) ≤ min (N sa ; N sc )
It shall be permitted to assume reduced values for V sa,y and V sc,y
corresponding to the use of an exponent α = 2. In this case the
reduced values for V sa,y and V sc,y shall also be used.
b) D.7.4.3.2, Section 17.6.4.3.2 (ACI 318−14) − If
æ N ua a , y ö
ç ç
÷ ÷ £ 0.2
è f N nc ø
then the full strength in shear shall be permitted:
æ V ua a , y ö æ V ua a , x ö
ç ç
÷ ÷ + ç ç
÷ ÷ £ 1.0
è f V nc , y ø è f V nc , x ø
c) D.7.4.3.3, Section 17.6.4.3.3 (ACI 318−14)− If
æ V ua a , y ö æ V ua a , x ö
æ N ua a , y ö
ç ç
÷ ÷ + ç ç
÷ ÷ > 0.2
÷ ÷ > 0.2 and ç ç
è f N nc ø
è f V nc , y ø è f V nc , x ø
then Eq. (D−32e), Eq. ( 17.6.4.3.a ACI318−14) applies:
a
a
æ N ua
ö æ V ua , y ö æ V ua a , x ö
+
£ 1.2
÷
÷
ç
÷ + ç
ç
÷
ç
÷ ç
è f N nc ø è f V nc , y ø è f V nc , x ø
d) D.7.4.3.4, Section 17.6.4.3.4 (ACI 318−14) − Alternatively,
instead of satisfying “a” through “c” , the interaction equation
may be satisfied:
5
a
a
æ N ua
ö 3 æ V ua , y
ç
÷ + ç
ç f V nc , y
è f N nc ø
è
5
ö 3 æ V ua a , x
+ ç
÷
ç f V
÷
nc , x
è
ø
5
ö 3
£ 1.0
÷
÷
ø
Cast-In Anchor Channel Product Guide, Edition 1 • 02/2019
191
α = 1 for anchor channels with max (V sa,y ; V sc,y ) > min (N sa ; N sc )
then the full strength in tension shall be permitted:
æ N ua a , y ö
ç ç
÷ ÷ £ 1.0
è f N nc ø
a) Anchor and connection between anchor and channel:
a
It shall be permitted to assume reduced values for V sl,y
corresponding to the use of an exponent α = 2. In this case the
reduced value for V sl,y shall also be used.
a) D.7.4.3.1, Section 17.6.4.3.1 (ACI 318−14) − If
æ V ua a , y ö æ V ua a , x ö
ç ç
÷ ÷ + ç ç
÷ ÷ £ 0.2
è f V nc , y ø è f V nc , x ø
2 0 . 5
In all other cases:
190
a
ö æ V ua b , x
÷ ÷ + ç ç
ø è f V sl , x
ESR-3520 Equation (45)
where:
dge distance required to develop full concrete capacity in
c ac : E
absence of anchor reinforcement.
For the use of anchor channels in lightweight concrete, the
modification factor λ shall be taken as 0.75 for all-lightweight
concrete and 0.85 for sand-lightweight concrete. Linear
interpolation shall be permitted if partial sand replacement is
used.
ö æ V ua b , y
÷ ÷ + ç ç
ø è f V sl , y
2
ö
÷ ÷ £ 1.0
ø
The minimum edge distance, minimum and maximum anchor
spacing and minimum member thickness shall be taken from
Table 8-1 ESR-3520. The critical edge distance, c ac , shall be
taken from Table 8-4 ESR-3520.
a
a
ö æ V ua b , x
÷ ÷ + ç ç
ø è f V sl , x
Anchor channels shall satisfy the requirements for edge
distance, spacing, and member thickness.
14. Design
Example
Minimum Member Thickness, Anchor Spacing, and Edge
Distance:
13. Field Fixes
The ICC-ES Acceptance Criteria AC232 includes amendments
to the ACI 318 anchoring to concrete provisions. These
amendments are given in Section 3.1 Strength Design —
Amendments to ACI 318. Part D.6.3.2 (ACI 318-11) and Section
17.5.3.2 (ACI 318-14) of these amendments requires the factor
ψ s,N to be modified when calculating concrete pryout strength in
shear. All of the parameters used to calculate ψ s,N in tension are
used except the parameter (N aua,i / N aua,1 ). The shear loads acting
on the anchor elements are substituted for the tension loads
such that (V aua,i / V aua,1 ) is used instead of (N aua,i / N aua,1 ).
12. Instructions
for Use
ESR-3520 Equation (41)
11. Best
Practices
k cp = 2 . 0
10. Design
Software
ESR-3520 Equation (42)
V cp, x = k cp N cb , lb ( N )
9. Special Anchor
Channel Design
V cp = V cp, x = 0 . 75 . k cp N cb , lb ( N )
Also with increasing load and stud elongation, the baseplate
rotates and loses contact with the concrete on the loaded side.
These two mechanisms act to further increase the eccentricity
between the applied shear load V and the stress resultant Vb
in the concrete. The moment resulting from this eccentricity
generates a compressive force C between baseplate and
concrete and a tensile force N in the stud. If the tensile force
in the stud exceeds the tensile capacity associated with the
maximum fracture surface that can be activated by the stud,
a fracture surface originating at the head of the stud and
projecting in conical fashion behind the stud forms. This is
defined as a pry-out failure.
8. Reinforcing
Bar Anchorage
where:
k cp = shall be taken from Table 8-10
N cb = n
ominal concrete breakout strength of the anchor under
consideration, lb (N), determined in accordance with
breakout in tension; however in the determination of the
modification factor ψ s,N , the values N aua,1 and N aua,i in Eq.
(10) shall be replaced by V aua,1 and V aua,i , respectively.
The nominal pryout strength, V cp,y , in shear of a single anchor of
an anchor channel with anchor reinforcement shall not exceed:
Figure 7.4.4.7 — Load-bearing mechanism of headed stud anchorage
subjected to shear loading (schematic).
7. Anchor Channel
Design Code
Failure load associated with pry-
out; The load-bearing mechanism
of a single headed stud anchorage
subjected to a shear load is illustrated
schematically in Figure 7.4.47. The
applied shear load gives rise to
bearing stresses in the concrete. With
increasing load, the surface concrete
is crushed or spalled, shifting the
centroid of resistance V b to a location deeper in the concrete.
5. Base material
Concrete Pryout Strength of Anchor Channels in Shear
Longitudinal to the Channel Axis фV cp,x
4. Design
Introduction