ICC ESR-1546 for HDA Undercut Anchors

ESR-1546
|
Most Widely Accepted and Trusted Page 14 of 16
Given
(2) HDA-P M10 anchors
static tension load
h
ef
= 3.94 in. (100 mm)
f ’
c
= 3,000 psi
Assume
1. uncracked concrete
2. ACI 318-14 17.3.3(c)
or ACI 318-11 D.4.3(c),
Condition B
No supplementary
reinforcing
Calculate
Controlling design
strength in tension
Calculation per ACI 318-14 Chapter 17,
ACI 318-11 Appendix D and this report.
ACI 318-14
Ref.
ACI 318-11
Ref.
Report
Ref.
Step 1. Calculate steel strength of anchor in tension
N
sa
=n A
se
f
uta
=2
󰇛
0.090
󰇜󰇛
116,000
󰇜
=20,880 lb
17.4.1.2 D.5.1.2 Table 5
Step 2. Calculate steel capacity
ϕ
N
s
=0.75 x 20,880=15,660 lb
17.3.3(a) D.4.3(a) Table 5
Step 3. Calculate concrete breakout strength of anchor in tension N
cbg
=
A

A

ψ
ec,N
ψ
ed,N
ψ
c,N
ψ
cp,N
N
b
17.4.2.1 D.5.2.1
§4.1.1
§ 4.1.3
Step 3a. Check 1.5h
ef
= 1.5
󰇛
3.94
󰇜
= 5.91 in.  c 3.0h
ef
= 3
󰇛
3.94
󰇜
= 11.82 in.  s
17.4.2.1 D.5.2.1 Table 5
Step 3b. Check s
min
= 4 in. < 6 in., c
min
= 3-1/8 in. < 4 in., h
min
= 7 in. < 180 mm
ok
17.7 D.8 Table 5
Step 3c. Calculate A
Nco
and A
Nc
for the anchorage: A
Nc0
=9h
ef
2
=9(3.94)
2
=139.7 in
2
A
Nc
=
󰇛
1.5h
ef
+ c
󰇜󰇛
3h
ef
+ s
󰇜
=
󰇟
1.5
󰇛
3.94
󰇜
+ 4
󰇠󰇟
3
󰇛
3.94
󰇜
+ 6
󰇠
= 176.6 in
2
<2A
Nc0
∴ ok
17.4.2.1 D.5.2.1 Table 5
Step 3d. e'
N
= 0, therefore ψ
ec,N
= 1 17.4.2.4 D.5.2.4 Table 5
Step 3e. Calculate N
b
=λk
c

f'
c
h
ef
1.5
=
󰇛
1.0
󰇜
30

3,000(3.94)
1.5
=12,850 lb
17.4.2.2 D.5.2.2 Table 5
Step 3f. Calculate modification factor for edge distance: ψ
ed,N
=0.7+0.3
4
1.5(3.94)
=0.90
17.4.2.5 D.5.2.5 Table 5
Step 3g. ψ
c,N
=1.0
17.4.2.6 D.5.2.6 Table 5
Step 3h. ψ
c
p
,N
=1.0
- - § 4.1.3
Step 3i. Calculate N
cbg
=
176.6
139.7
x 1.00 x 0.90 x 1.00 x 1.00 x 12,850=14,621 lb
17.4.2.1 D.5.2.1
§ 4.1.3
Table 5
Step 4. Controlling design strength:
ϕ
N
cbg
=0.65 x 14,621 lb = 9,504 lb <
ϕ
N
s
∴
ϕ
N
cbg
controls
17.3.3(c) D.4.3(c) Table 5
FIGURE 9—EXAMPLE CALCULATION