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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

Concrete Pryout Strength of Anchor Channels in Shear

Longitudinal to the Channel Axis фV

cp,x

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

to a location deeper in the concrete.

Figure 7.4.4.7 — Load-bearing mechanism of headed stud anchorage

subjected to shear loading (schematic).

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.

0.2

)(,NV

cbxcp,

Nlbk

ESR-3520 Equation (41)

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).

Ncp,Nc,Nco,Ned,Ns,bcb

ψψψψψNN ×××××=

where:

= shall be taken from Table 8-10

= nominal 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

ua,1

and N

ua,i

in Eq.

(10) shall be replaced by V

ua,1

and V

ua,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:

)(,N.75.0VV

cbxcp,cp

Nlbkcp==

ESR-3520 Equation (42)

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

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

ua,i

/ N

ua,1

). The shear loads acting

on the anchor elements are substituted for the tension loads

such that (V

ua,i

/ V

ua,1

) is used instead of (N

ua,i

/ N

ua,1

Minimum Member Thickness, Anchor Spacing, and Edge

Distance:

Anchor channels shall satisfy the requirements for edge

distance, spacing, and member thickness.

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

, shall be

taken from Table 8-4 ESR-3520.

: Edge distance required to develop full concrete capacity in

absence of anchor reinforcement.

Requirements for lightweight concrete:

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.

7.5 INTERACTION

EQUATIONS:

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

0.1

ESR-3520 Equation (43)

( ) ( )

[ ]

5.0

xua,

yua,

VVV +=

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.

a) Anchor and connection between anchor and channel:

,, ,,

max , max , max , 1.0

ua y ua y

ua x ua x

ua ua

sa sc sa y sc y sa x sc x

NN V V V V

ff f f f f

æö

++£

ç÷

èø

ESR-3520 Equation (44)

where:

α = 2 for anchor channels with max (V

sa,y

; V

sc,y

) ≤ min (N

; N

)

In all other cases:

α = 1 for anchor channels with max (V

sa,y

; V

sc,y

) > min (N

; N

)

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) At the point of load application:

1.0

ua y

ua x

sl sl y sl x

NV V

ff f

æö

++£

ç÷

èø

, ,,

1.0

u flex ua y

ua x

s flex sl y sl x

M VV

f ff

æ öæ ö

æö

++£

ç ÷ç ÷

ç÷

ç ÷ç ÷

èø

è øè ø

ESR-3520 Equation (45)

ESR-3520 Equation (46)

where:

α = 2 for anchor channels with V

sl,y

≤ N

s,l

α = 1 for anchor channels with V

sl,y

> N

s,l

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.

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).

a) D.7.4.3.1, Section 17.6.4.3.1 (ACI 318−14) − If

0.2

ua y

ua x

nc y nc x

æö

+ £

ç÷

èø

then the full strength in tension shall be permitted:

1.0

ua y

æö

ç÷

èø

b) D.7.4.3.2, Section 17.6.4.3.2 (ACI 318−14) − If

0.2

ua y

æö

ç÷

èø

then the full strength in shear shall be permitted:

1.0

ua y

ua x

nc y nc x

æö

+ £

ç÷

èø

c) D.7.4.3.3, Section 17.6.4.3.3 (ACI 318−14)− If

0.2 0.2

ua y ua y

ua x

nc y nc x nc

and

VV N

ff f

æö

+> >

ç÷

èø

then Eq. (D−32e), Eq. ( 17.6.4.3.a ACI318−14) applies:

1.2

ua y

ua x

nc nc y nc x

NV V

ff f

æö

++£

ç÷

èø

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:

1.0

ua y

ua x

nc nc y nc x

NV V

ff f

æö

++£

ç÷

èø