ASD/LRFD Manual - American Wood Council
ASD/LRFD Manual - American Wood Council
ASD/LRFD Manual - American Wood Council
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<strong>ASD</strong>/<strong>LRFD</strong> MANUAL FOR ENGINEERED <strong>Wood</strong> Construction<br />
87<br />
M11.5 Adjustment of Reference Design Values<br />
Dowel-type connections must be designed by applying<br />
all applicable adjustment factors to the reference<br />
withdrawal design value or reference lateral design value<br />
for the connection. NDS Table 10.3-1 lists all applicable<br />
adjustment factors for dowel-type connectors. Table<br />
M11.3-1 shows the applicability of adjustment factors<br />
for dowel-type fasteners in a slightly different format for<br />
the designer.<br />
Table M11.3-1 Applicability of Adjustment Factors for Dowel-Type Fasteners 1<br />
Allowable Stress Design Load and Resistance Factor Design<br />
Lateral Loads<br />
Dowel-Type Fasteners Z′ = Z C D C M C t C g C ∆ C eg C di C tn Z′ = Z C M C t C g C ∆ C eg C di C tn K F φ z λ<br />
Withdrawal Loads<br />
Nails, Spikes, Lag Screws,<br />
<strong>Wood</strong> Screws, and Drift Pins<br />
W′ = W C D C M C t C eg C tn Z′ = Z C M C t C eg C tn K F φ z λ<br />
1. See NDS Table 10.3.1 footnotes for additional guidance on application of adjustment factors for dowel-type fasteners.<br />
Example of a Dowel-Type Fastener<br />
Loaded Laterally<br />
Example of a Dowel-Type Fastener<br />
Loaded in Withdrawal<br />
For a single dowel-type fastener installed in side grain<br />
perpendicular to the length of the wood member, meeting<br />
the end and edge distance and spacing requirements of NDS<br />
11.5.1, used in a normal building environment (meeting the<br />
reference conditions of NDS 2.3 and 10.3), and not a nail<br />
or spike in diaphragm construction, the general equation<br />
for Z′ reduces to:<br />
for <strong>ASD</strong>:<br />
Z′ = Z C D<br />
for <strong>LRFD</strong>:<br />
Z′ = Z K F φ z λ<br />
M11.6 Multiple Fasteners<br />
For a single dowel-type fastener installed in side grain<br />
perpendicular to the length of the wood member, used in<br />
a normal building environment (meeting the reference<br />
conditions of NDS 2.3 and 10.3), the general equation for<br />
W′ reduces to:<br />
for <strong>ASD</strong>:<br />
W′ = W C D<br />
for <strong>LRFD</strong>:<br />
W′ = W K F φ z λ<br />
Installation Requirements<br />
To achieve stated design values, connectors must<br />
comply with installation requirements such as spacing of<br />
connectors, minimum edge and end distances, proper drilling<br />
of lead holes, and minimum fastener penetration.<br />
11<br />
M11: DOWEL-TYPE FASTENERS<br />
Local stresses in connections using multiple fasteners<br />
can be evaluated in accordance with NDS Appendix E.<br />
<strong>American</strong> Forest & paper association
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