Steel Deck Fastening Systems
Steel Deck Fastener Design and Selection 1.1
Calculation steps
SDI
DDM03
Ref. HNA
Technical
Guide
Eq.
3.3-3 Sec.
1.1.8
and
Tables
7 and 9
Roof
Deck
Const.
Handbook Sec.
1.2.3
Step 7: Calculate diaphragm stiffness:
E x t
29,500 x 0.0358
G' =
=
= 86 kips/in.
3.78 + 0.9 x D n + C 3.78 + 0.9 x 5.39 + 3.65
1000
1000
=
= 11.6 micro-inches/lb
G'
85.99
where:
D
1164
D n =
=
= 5.39
< x 12 18 x 12
1
t x S f
C = E x
x α + α + n x S f
x < x 12
w
1
2
s
S s
1
0.0358 x 0.0066
C = 29,500 x
x 2 + 2 + 18 x 0.0066
36
0.0159
F =
(
(
)
)
x 18 x 12 = 3.65
Step 8: Calculate nominal uplift resistance:
K x T n,f
6.00 x 1,680
T n =
=
= 560 psf
3 x 6
C x < v
Where:
K = Number of frame fasteners per deck sheet per joist/beam = 6.00
C = Width of deck sheet = 3 feet
T n,F = Controlling ultimate tension capacity of frame fastener = 560 lb x 3.0 = 1,680 lb
Step 9: Apply uplift safety factor to determine allowable uplift resistance:
T n
560
T n (ASD) =
=
= 187 psf ≥ 35 psf
3.00
Ω
UP
Step 10: Check combined loading:
Ω x Q
Ω x T
0.85 x (
) + ( UP
) ≤ 1.0
S
T n
0.85 x (
Sec.
4.10
2.35 x 650
3.00 x 35
) + (
) ≤ 1.0 0.843 ≤ 1.0
1981
560
Note: The Hilti Profis DF Diaphragm software provides full calculations for diaphragm shear and stiffness when desired.
Hilti is a leading manufacturer of direct fastening systems for
steel and metal applications. As a member of the Steel Deck
Institute (SDI), Hilti participates in and supports steel deck
industry research at leading universities and test labs. Recent
research projects with Hilti direct fastening systems have
included inelastic seismic deck diaphragms and deep deck /
cellular deck diaphragms.
Diaphragm data is calculated in accordance with SDI
Diaphragm Design equations using specific Hilti fastener
strength and stiffness values with data correlation adjustment
factors in accordance with ICC-ES AC43 requirements.
Independent tests are the best guide to product performance
and reliability, a philosophy to which Hilti and the SDI
subscribe. The support for ongoing research programs
is indicated by the number and scope of tests already
performed and by the policy of sponsoring new tests when
new products or applications are introduced. Hilti provides
direct fastening system performance data, ICC-ES Evaluation
Service Reports, design software, fire ratings and load test
results for Hilti direct fastening systems used in steel deck
applications.
Hilti, Inc. (US) 1-800-879-8000 | www.us.hilti.com I en español 1-800-879-5000 I Hilti (Canada) Corp. 1-800-363-4458 I www.hilti.ca I PTG Decking Supplement 2014 23