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STUD ANCHOR DESIGN
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Combined Tension, Shear and Moment |
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Result Summary
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Anchor Rod Embedment, Spacing and Edge Distance
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Warn
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Overall
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ratio
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=
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0.66
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OK
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Seismic Design
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Tension
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=
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OK
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Shear
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=
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OK
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Design Code Reference
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Welded stud design based on
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Code Abbreviation
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ACI 318-14 Building Code Requirements for Structural Concrete and Commentary |
ACI 318-14
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PIP STE05121 Anchor Bolt Design Guide-2006
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PIP STE05121
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Welded Stud Data
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Code Reference
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Factored moment |
Mu |
= |
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[kip-ft] |
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Factored tension or compression
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Nu
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=
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[kips]
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in compression
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Factored shear force
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Vu
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=
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[kips]
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No of bolt line for resisting moment |
= |
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No of bolt along outermost bolt line |
= |
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No of bolt along side edge |
nbd |
= |
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PIP STE05121
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Outermost bolt line spacing s1
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s1
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=
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[in]
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3.00
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OK
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Page A -1 Table 1
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Outermost bolt line spacing s2
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s2
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=
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[in]
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3.00
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OK
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Max spacing between anchors in tension |
= |
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[in] |
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Column depth |
d |
= |
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[in] |
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Concrete strength
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f'c
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=
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[ksi]
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Welded stud material
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=
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Anchor tensile strength
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futa
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=
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65.0 |
[ksi]
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ACI 318-14
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Anchor is ductile steel element
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2.3 & 17.3.3 (a)
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Welded stud diameter
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da
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=
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[in]
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Anchor effective cross section area
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Ase
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=
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0.442
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[in2]
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Welded stud head bearing area
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Abrg
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= |
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[in2]
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PIP STE05121
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Welded stud edge distance c1
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c1
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=
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[in]
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4.50
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OK
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Page A -1 Table 1
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Welded stud edge distance c2
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c2
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=
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[in]
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4.50
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OK
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Welded stud edge distance c3
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c3
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=
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[in]
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4.50
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OK
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Welded stud edge distance c4
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c4
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=
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[in]
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4.50
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OK
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Welded stud embedment depth
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hef
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=
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[in]
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ACI 318-14
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ci ≥ 1.5hef for at least two edges to avoid reducing of hef when Nu > 0 |
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Warn
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17.4.2.3 |
Welded stud adjusted hef for design |
hef |
= |
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[in]
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9.00
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Warn
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17.4.2.3 |
Concrete thickness |
ha
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=
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[in]
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15.00
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OK
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For conc shear breakout check use
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Number of anchor at bolt line 1 |
n1 |
=
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Number of anchor at bolt line 2 |
n2 |
= |
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Total no of welded stud |
n |
= |
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No of welded stud carrying tension
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nt
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=
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No of welded stud carrying shear
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ns
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=
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Supplementary reinforcement |
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ACI 318-14
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For tension |
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= |
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Condition A
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17.3.3 (c) |
For shear |
Yc,v |
= |
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Condition A
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17.5.2.7 |
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ACI 318-14
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Provide built-up grout pad ?
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=
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17.5.1.3
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Concrete cracking |
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= |
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17.4.2.6, 17.4.3.6, 17.5.2.7 |
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ACI 318-14
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Seismic design category SDC >= C
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=
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17.2.3.1
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Welded stud load E <= 0.2U
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Tensile
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=
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Shear
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=
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17.2.3.4.1 & 17.2.3.5.1
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Welded stud satisfies opion
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Tensile
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=
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Shear
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=
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17.2.3.4.3 & 17.2.3.5.3
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Strength reduction factors
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ACI 318-14
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Anchor reinforcement
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fs
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=
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0.75
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17.4.2.9 & 17.5.2.9
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Anchor rod - ductile steel
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ft,s
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=
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0.75
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fv,s
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=
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0.65
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17.3.3 (a)
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Concrete |
ft,c
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=
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0.75 Cdn-A
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fv,c
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=
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0.75 Cdn-A
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17.3.3 (c)
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CONCLUSION
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Anchor Rod Embedment, Spacing and Edge Distance
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Warn
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Overall
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ratio
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=
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0.66
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OK
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Tension
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Anchor Rod Tensile Resistance
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ratio
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=
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0.13
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OK
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Concrete Tensile Breakout Resistance |
ratio
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=
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0.40
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OK
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Anchor Pullout Resistance
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ratio
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=
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0.16
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OK
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Side Blowout Resistance
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ratio
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=
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0.00
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NA
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Shear
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Anchor Rod Shear Resistance
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ratio
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=
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0.07
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OK
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Concrete Shear Breakout Resistance - Perpendicular To Edge |
ratio
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=
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0.39
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OK
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Concrete Shear Breakout Resistance - Parallel To Edge |
ratio
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=
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0.23
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OK
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Concrete Pryout Shear Resistance |
ratio
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= |
0.19
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OK
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Tension Shear Interaction
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Tension Shear Interaction
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ratio
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=
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0.66
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OK
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Seismic Design
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ACI 318-14
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Tension
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Applicable
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OK
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17.2.3.4
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Seismic SDC>=C and E>0.2U , Option D is selected to satisfy additional seismic requirements as per 17.2.3.4.3
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Shear
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Applicable
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OK
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17.2.3.5
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Seismic SDC>=C and E>0.2U , Option C is selected to satisfy additional seismic requirements as per 17.2.3.5.3
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Assumptions
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ACI 318-14
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1. Concrete is cracked
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17.4.2.6, 17.4.3.6, 17.5.2.7
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2. Condition A - supplementary reinforcement provided
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17.3.3 (c)
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3. Load combinations shall be per ACI 318-14 5.3.1
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17.3.3
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4. Shear load acts through center of bolt group Yec,V =1.0 |
17.5.2.5 |
5. For anchor group subject to moment, the anchor tensile load is designed using elastic analysis |
17.2.1 |
and there is no redistribution of the forces between highly stressed and less stressed anchors |
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6. For anchor tensile force calc in anchor group subject to moment, assume the compression |
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resultant is at the outside edge of the compression flange and base plate exhibits rigid-body
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rotation. This simplified approach yields conservative output |
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CACULATION
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Anchor Tensile Force |
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Single bolt tensile force |
T1 |
= |
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[kips] |
No of bolt for T1 nT1 |
= |
2.0
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Sum of bolt tensile force |
Nu |
= |
S ni Ti |
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= |
5.61
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[kips] |
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Tensile bolts outer distance stb |
stb |
= |
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[in] |
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Eccentricity e'N -- distance between resultant of tensile load and centroid of anchors |
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loaded in tension |
e'N |
= |
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[in] |
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Eccentricity modification factor |
Ψec,N |
= |
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= |
1.00
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Anchor Rod Tensile Resistance
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ACI 318-14
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f t,s Nsa
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=
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f t,s Ase futa
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=
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21.55
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[kips]
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17.4.1.2 Eq 17.4.1.2
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ratio
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=
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0.13
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>
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T1
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OK
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Concrete Tensile Breakout Resistance |
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ACI 318-14
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Nb |
= |
24 l √fc hef1.5 if hef <11" or hef>25" |
= |
21.32
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[kips]
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17.4.2.2 Eq 17.4.2.2a |
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16 l √fc hef(5/3) if 11"≤ hef ≤25" |
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17.4.2.2 Eq 17.4.2.2b |
Projected conc failure area |
1.5 hef |
= |
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= |
8.00
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[in] |
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ANC |
= |
[stb+min(c1,1.5hef)+min(c3,1.5hef)]x |
= |
338.0
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[in2] |
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[s2+min(c2,1.5hef)+min(c4,1.5hef)] |
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ANCO |
= |
9 hef2 |
= |
256.0
|
[in2] |
17.4.2.1 Eq 17.4.2.1c |
|
ANC |
= |
min ( ANC, nt ANCO ) |
= |
338.0
|
[in2] |
17.4.2.1 |
Min edge distance |
cmin |
= |
min( c1, c2, c3, c4 ) |
= |
5.00
|
[in] |
|
Eccentricity effects |
Ψec,N |
= |
|
= |
1.00
|
|
17.4.2.4 |
Edge effects |
Ψed,N |
= |
min[ (0.7+0.3cmin/1.5hef), 1.0 ] |
= |
0.89
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|
17.4.2.5 |
Concrete cracking |
Ψc,N |
= |
1.00 for cracked concrete
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17.4.2.6 |
Concrete splitting |
Ψcp,N |
= |
1.00 for cast-in anchor |
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17.4.2.7 |
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Concrete breakout resistance |
ftcNcbg |
= |
ftc |
ANC |
Ψec,N Ψed,N Ψc,N Ψcp,N Nb |
ANCO |
|
= |
18.73
|
[kips]
|
17.4.2.1 Eq 17.4.2.1b
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Seismic design strength reduction |
|
= |
x 0.75 applicable
|
= |
14.05
|
[kips]
|
17.2.3.4.4 |
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ratio
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=
|
0.40
|
>
|
Nu
|
OK
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Anchor Pullout Resistance
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ACI 318-14
|
Single bolt pullout resistance
|
N p
|
=
|
8 Abrg fc'
|
=
|
32.66
|
[kips]
|
17.4.3.4 Eq 17.4.3.4
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ft,c Npn
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=
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f t,c Ψc,p Np
|
=
|
22.86
|
[kips]
|
17.4.3.1 Eq 17.4.3.1
|
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Ψc,p
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=
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1.00 for cracked concrete
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17.4.3.6
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f t,c
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=
|
0.70
|
pullout strength is always Condition B
|
17.3.3(c)
|
Seismic design strength reduction
|
|
=
|
x 0.75 applicable
|
=
|
17.14
|
[kips]
|
17.2.3.4.4
|
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ratio
|
=
|
0.16
|
>
|
T1
|
OK
|
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Side Blowout Resistance
|
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Failure Along Pedestal Width Edge
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|
ACI 318-14
|
Tensile load carried by anchors close to edge which may cause side-face blowout
|
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along pedestal width edge
|
Nbuw
|
= |
nT1 T1 |
=
|
5.61
|
[kips]
|
R17.4.4.2
|
|
c
|
=
|
min ( c1 , c3 )
|
=
|
5.00
|
[in]
|
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s
|
=
|
s2
|
=
|
16.00
|
[in]
|
|
Check if side blowout applicable
|
hef
|
=
|
12.00
|
[in]
|
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<
|
2.5c
|
side bowout is NOT applicable
| 17.4.4.1
|
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Group side blowout resistance
|
ftc Nsbg
|
=
|
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=
|
0.00
|
[kips]
|
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|
Govern Tensile Resistance
|
Nr
|
=
|
min(f nt Nsa , fNcbg , fnt Npn , fNsbg) |
=
|
14.05
|
[kips]
|
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Anchor Rod Shear Resistance
|
|
|
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|
ACI 318-14
|
|
f v,sVsa
|
=
|
f v,s ns Ase futa
|
=
|
74.70
|
[kips]
|
17.5.1.2 Eq 17.5.1.2a |
Reduction due to built-up grout pad
|
|
=
|
x 1.0 , not applicable
|
=
|
74.70
|
[kips]
|
17.5.1.3
|
|
ratio
|
=
|
0.07
|
>
|
Vu
|
OK
|
|
|
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|
Conc. Shear Breakout Resistance - Perpendicular To Edge |
|
|
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|
Only Case 2 needs to be considered when anchors are rigidly connected to the attachment |
Fig. R17.5.2.1b notes |
This applies to welded stud case so only Mode 2 is considered for shear checking |
in Case 2 |
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Mode 2 Failure cone at back anchors |
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|
Bolt edge distance |
ca1 |
= |
c1 + s1 |
= |
21.00
|
[in] |
ACI 318-14
|
Limiting ca1 when anchors are influenced by 3 or more edges |
= |
Yes
|
|
17.5.2.4 |
Bolt edge distance - adjusted |
ca1 |
= |
ca1 needs to be adjusted
|
= |
10.00
|
[in] |
17.5.2.4 |
|
c2 |
= |
|
= |
5.00
|
[in] |
|
|
1.5ca1 |
= |
|
= |
15.00
|
[in] |
ACI 318-14
|
|
Avc |
= |
[min(c2,1.5ca1)+ s2 + min(c4,1.5ca1)]x |
= |
390.0
|
[in2] |
17.5.2.1 |
|
|
|
min(1.5ca1, ha) |
|
|
|
ACI 318-14
|
|
Avco |
= |
4.5ca12 |
= |
450.0
|
[in2] |
17.5.2.1 Eq 17.5.2.1c |
|
Avc |
= |
min ( Avc, n2 Avco ) |
= |
390.0
|
[in2] |
17.5.2.1 |
|
le |
= |
min( 8da , hef ) |
= |
6.00
|
[in] |
17.5.2.2 |
|
Vb1 |
= |
|
= |
20.95
|
[kips] |
17.5.2.2 Eq 17.5.2.2a |
|
Vb2 |
= |
|
= |
20.52
|
[kips] |
17.5.2.2 Eq 17.5.2.2b |
|
Vb |
= |
min( Vb1 , Vb2 ) |
= |
20.52
|
[kips] |
17.5.2.2 |
Eccentricity effects |
Ψec,v |
= |
1.0 shear acts through center of group |
|
|
|
17.5.2.5 |
Edge effects |
Ψed,v |
= |
min[ (0.7+0.3c2/1.5ca1), 1.0 ] |
= |
0.80
|
|
17.5.2.6 |
Concrete cracking |
Ψc,v |
= |
concrete is cracked
|
= |
1.20
|
|
17.5.2.7 |
Member thickness |
Ψh,v |
= |
max[ (sqrt(1.5ca1 / ha) , 1.0 ] |
= |
1.00
|
|
17.5.2.8 |
|
|
|
|
|
|
|
ACI 318-14
|
Conc shear breakout resistance |
Vcbg |
= |
fv,c |
Avc |
Ψec,v Ψed,v Ψc,v Ψh,v Vb |
Avco |
|
= |
12.81
|
[kips] |
17.5.2.1 Eq 17.5.2.1b |
|
ratio |
= |
0.39
|
>
|
Vu |
OK
|
|
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Conc. Shear Breakout Resistance - Parallel To Edge |
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ACI 318-14
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Only Case 2 needs to be considered when anchors are rigidly connected to the attachment |
Fig. R17.5.2.1b notes |
This applies to welded stud case so only Mode 2 is considered for shear checking |
in Case 2 |
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Mode 2 Shear taken evenly by back welded studs, strength check against 0.5 x Vu |
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Bolt edge distance |
ca1 |
= |
min(c2 , c4) |
= |
5.00
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[in] |
ACI 318-14
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Limiting ca1 when anchors are influenced by 3 or more edges |
= |
No
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17.5.2.4 |
Bolt edge distance - adjusted |
ca1 |
= |
ca1 needs NOT to be adjusted
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= |
5.00
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[in] |
17.5.2.4 |
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1.5ca1 |
= |
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= |
7.50
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[in] |
ACI 318-14
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Avc |
= |
[min(s1+c1,1.5ca1) +min(c3,1.5ca1)]x |
= |
93.8
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[in2] |
17.5.2.1 |
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min(1.5ca1, ha) |
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ACI 318-14
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Avco |
= |
4.5ca12 |
= |
112.5
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[in2] |
17.5.2.1 Eq 17.5.2.1c |
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Avc |
= |
min ( Avc, nbd Avco ) |
= |
93.8
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[in2] |
17.5.2.1 |
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le |
= |
min( 8da , hef ) |
= |
6.00
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[in] |
17.5.2.2 |
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Vb1 |
= |
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= |
7.41
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[kips] |
17.5.2.2 Eq 17.5.2.2a |
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Vb2 |
= |
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= |
7.26
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[kips] |
17.5.2.2 Eq 17.5.2.2b |
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Vb |
= |
min( Vb1 , Vb2 ) |
= |
7.26
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[kips] |
17.5.2.2 |
Eccentricity effects |
Ψec,v |
= |
1.0 shear acts through center of group |
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17.5.2.5 |
Edge effects |
Ψed,v |
= |
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1.00 |
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17.5.2.1 (c) |
Concrete cracking |
Ψc,v |
= |
concrete is cracked
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= |
1.20
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17.5.2.7 |
Member thickness |
Ψh,v |
= |
max[ (sqrt(1.5ca1 / ha) , 1.0 ] |
= |
1.00
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17.5.2.8 |
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ACI 318-14
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Conc shear breakout resistance |
Vcbg-p |
= |
2xfv,c |
Avc |
Ψec,v Ψed,v Ψc,v Ψh,v Vb |
Avco |
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= |
21.77
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[kips] |
17.5.2.1 Eq 17.5.2.1b |
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x 2 side |
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17.5.2.1 (c) |
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ratio |
= |
0.23
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>
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Vu |
OK
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Conc. Pryout Shear Resistance
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ACI 318-14
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kcp |
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2.0
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17.5.3.1 |
Factored shear pryout resistance |
fv,cVcpg |
= |
fv,c kcp Ncbg |
= |
34.97
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[kips] |
17.5.3.1 Eq 17.5.3.1b |
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f v,c
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0.7 pryout strength is always Condition B |
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17.3.3 (c) |
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Seismic design strength reduction
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x 0.75 applicable
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26.23
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[kips]
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17.2.3.4.4
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ratio
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=
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0.19
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>
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Vu |
OK
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Govern Shear Resistance
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Vr
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=
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min ( fVsa , fVcbg , fVcbg-p , fVcpg ) |
=
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12.81
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[kips]
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Tension Shear Interaction
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ACI 318-14
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Check if Nu >0.2f Nn and Vu
>0.2f Vn
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=
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Yes
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17.6.1 & 17.6.2
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Nu / f Nn + Vu / f Vn
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=
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0.79
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17.6.3 Eq 17.6.3
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ratio
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=
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0.66
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<
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1.2
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OK
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Seismic Design
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Tension
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Applicable
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OK
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Option D is selected.
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ACI 318-14
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User has to ensure that the tensile load Nu user input above includes
the seismic load E, with E increased
by multiplying overstrength factor Ωo
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17.2.3.4.3(d)
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Seismic SDC>=C and E>0.2U , Option D is selected to satisfy additional seismic requirements as per 17.2.3.4.3
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Shear
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Applicable
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OK
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Option C is selected.
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ACI 318-14
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User has to ensure that the shear load Vu user input above includes the
seismic load E, with E increased
by multiplying overstrength factor Ωo
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17.2.3.5.3(c)
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Seismic SDC>=C and E>0.2U , Option C is selected to satisfy additional seismic requirements as per 17.2.3.5.3
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