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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

Figure 7.3.2.8 — Anchor channel with influence of one edge and two

corners.

Figure 7.3.2.9 — Anchor channel with influence of two edges and

one corner.

s,N

= modification factor influencing the location of

adjacent anchors

Channels with more than two anchors and loaded in the

span behave like continuous beams on springs, whereby the

stiffness of the springs corresponds to the load-displacement

curve of the anchor. The concrete cone capacity of the anchor

in question is influenced by the distance of and the load on

neighboring anchors. This is taken into account by multiplying

the basic concrete cone capacity N

, with the modification

factor ψ

s,N

. The factor ψ

s,N

replaces the ratio A

c,N

/A°

c,N

, the factor

ec,N

of ACI equation of concrete breakout of headed stud

anchor. For anchor channel with two anchors the factor ψ

s,N

and

the product (A

c,N

/A°

c,N

)ψ

ec,N

give practically the same results.

The modification factor to account for the influence of location

and loading of adjacent anchors, ψ

s,N

, shall be computed in

accordance with Eq below.

Figure 7.3.2.10— Example of anchor channel with non-uniform tension

forces.

1.5

Ncr,

Ns,

ESR-3520 Equation (10)

efef

Ncr

s 3

1.7

3.1

8.22

in.

efef

Ncr

s 3

180

3.1

8.22

mm.

ESR-3520 Equation (11)

= distance between the anchor under consideration and

≤ s

cr,N

adjacent anchor, in. (mm)

= tension force of a neighboring anchor

= tension force of the anchor which resistance is determined

s,N3

1.5 1.5 1.5

,2 ,3 ,4

, ,1 , ,1 , ,1

11 1 1

aaa

ua ua ua

aaa

cr N ua cr N ua cr N ua

NNN

sN sN sN

é ùé ùé ù

æö æö æö

ê úê úê ú

+ -×+ -×+ -×

ç÷ ç÷ ç÷

ê úê úê ú

èø èø èø

ë ûë ûë û

If an anchor channel is located with the edge c

≥ c

cr,N

all directions the modification factors for concrete edge and

corner effect is taken as 1. For applications where c

≤ c

cr,N

for example close to the edge or corner, equation should be

reduced according to the modification factors given below.

Figure 7.3.2.11 - Idealize failure plane in concrete due to tension forces.

ed,N

= modification factor for edge effect

The modification factor for edge effect of anchors loaded in

tension, ψ

ed,N

, shall be computed in accordance with Eq. (12) or

(13)

1.0

cc If

1.0

cc If

0.5

Ncr,

Ned,

Ncr,a1

Ned,

Ncr,a1

then

ESR-3520 Equation (12)

ESR-3520 Equation (13)

where:

efNcrNcr

hsc 5.15.0

³=

ESR-3520 Equation (14)

If anchor channels are located in a narrow concrete member

with multiple edge distances c

a1,1

and c

a1,2

(as shown in Figure

7.3.2.12), the minimum value of c

a1,1

and c

a1,2

shall be inserted in

Eq. (13).

Figure 7.3.2.12 a)— at an edge

Figure 7.3.2.12 b)— in a narrow member

Figure 7.3.2.12 — Idealized projected area of anchor of an anchor channel

loaded in tension near a corner (top) near a corner and in a narrow member

(bottom)

co,N

= modification factor for corner influence

The modification factor for corner effect of anchors loaded in

tension, ψ

co,N

, shall be computed in accordance with Eq. (15) or

(16)

1.0

cc If

1.0

cc If

0.5

Ncr,

Nco,

Ncr,a2

Nco,

Ncr,a2

then

ESR-3520 Equation (15)

ESR-3520 Equation (16)

efNcrNcr

hsc 5.15.0

³=

ESR-3520 Equation (14)

=distance of the anchor under consideration to the corner

(see figure 7.3.2.13 a, b).

If an anchor is influenced by two corners (as illustrated in Figure

7.3.2.13 c), the factor ψ

co,N

shall be computed for each of the

values c

a2,1

and c

a2,2

and the product of the factors, ψ

co,N

, shall be

inserted in Eq. (6).

0.5

2.1

, ,3

0.5

2.2

, ,3

1.0

co N

cr N

co N

cr N

and

æö

= £

ç÷

èø

æö

= £

ç÷

èø

a) b)

c) d)

Figure 7.3.2.13 — Anchor channel with the influence of one edge and one

corner (a and b), two corners and one edge (c), and two edges and one

corner (d).

c,N

= modification factor for cracked/uncracked concrete

A cracked tension zone is assumed because concrete

possesses relatively low tensile strength, which may be fully

or partly used by internal or restraint tensile stresses not taken

into account in the design. The load-bearing behavior of an

anchor can be significantly influenced by the presence of a

crack passing through the anchor location. For anchor channels

located in a region of a concrete member where analysis

indicates no cracking at service load levels, the following

modification factor shall be permitted

c,N

= 1.25

Where analysis indicates cracking at service load levels ψ

c,N

shall be taken as 1.0. The cracking in the concrete shall be

controlled by flexural reinforcement distributed in accordance

with ACI 318-14 Section 24.3.2 and 24.3.3, or equivalent crack

control shall be provided by confining reinforcement.

Concrete ψ

c,N

Cracked 1

Uncracked 1.25

The anchor qualification tests of ACI 355.2 or ACI 355.4 require

that anchors in cracked concrete zones perform well in a crack

that is 0.012 in. wide. If wider cracks are expected, confining

reinforcement to control the crack width to approximately 0.012

in. should be provided.