PART 4 SHEAR LOAD
Steel Failure Mode
Equation post-Installed anchor V sa = 0.6 A se , V f uta
Equation 318-14 Chapter 17 Provision Comments for PROFIS Engineering post-Installed anchor
V sa
= ESRvalue
17.5.1.1 The nominal strength of an anchor in shear as governed by steel , V sa
, shall be evaluated by calculations based on the properties of the anchor material and the physical dimensions of the anchor . Where concrete breakout is a potential failure mode , the required steel shear strength shall be consistent with the assumed breakout surface .
17.5.1.2 The nominal strength of an anchor in shear , V sa
, shall not exceed ( a ) through ( c ): …………………………………………………..
( b ) For cast-in headed bolt and hooked bolt anchors and for post-installed anchors where sleeves do not extend through the shear plane
V sa
= 0.6 A se , V f uta
( 17.5.1.2b ) where A se , V is the effective cross-sectional area of an anchor in shear , in . 2 , and f uta shall not be taken greater than the smaller of 1.9fy a and 125,000 psi . ( c ) For post-installed anchors where sleeves extend through the shear plane , V sa shall be based on the results of tests performed and evaluated according to ACI 355.2 . Alternatively , Eq . ( 17.5.1.2b ) shall be permitted to be used .
Excerpt from a mechanical anchor ICC-ESR showing V sa and V sa , eq values .
ICC-ESR-1917 Table 3
Design information
Effective min . embedment
Steel strength in shear
Steel strength in shear , seismic
Symbol Units
Nominal anchor diameter ( in .) 3 / 8 1 / 2 5 / 8 3 / 4 h ef in . 1-1 / 2 2 2-3 / 4 2 3-1 / 4 3-1 / 8 4 3-1 / 4 3-3 / 4 4-3 / 4
V sa lb 2180 3595 5495 8090 13,675
V sa , eq lb 2180 2255 5495 7600 11,475
Excerpt from an adhesive anchor ICC-ESR showing parameters for V sa
.
ICC-ESR-3814 Table 6A
DESIGN INFORMATION Symbol Units
ASTM F1554
Gr . 36
Nominal strength as governed by steel strength
Reduction factor , seismic shear
Nominal rod diameter ( in ). 3 / 8 1 / 2 5 / 8 3 / 4 7 / 8 1 1-1 / 4
V sa lb - 4940 7865 11,640 16,070 21,080 33,725 α V , seis
- 0.60
ACI 318-14 Chapter 2 defines the parameter V sa as :
“ nominal shear strength of a single anchor or individual anchor in a group of anchors as governed by the steel strength ”.
V sa is always calculated for a single anchor when designing with ACI 318-14 provisions .
Post-installed mechanical anchors can be shown compliance under the International Building Code ( IBC ) via testing per the ICC-ES acceptance criteria AC193 and the ACI test standard ACI 355.2 . Data derived from this testing is given in an ICC-ESR . Pre-calculated V sa
-values derived from AC193 / ACI 355.2 testing are given in mechanical anchor ICC-ESR design tables . Although parameters such as A se , V and f uta may be given in the ICC-ESR , PROFIS Engineering uses the pre-calculated V sa
-values to define the nominal steel strength in shear . Mechanical anchor ESR-values are specific to static ( V sa
) or seismic ( V sa , eq
) load conditions . In lieu of Equation ( 17.5.1.2b ), the Equations section of the PROFIS Engineering report for a mechanical anchor references “ V sa
= ESR value ” for static load conditions and “ V sa , eq
= ESR value ” for seismic load conditions ”.
Post-installed adhesive anchor systems can be shown compliance under the IBC via testing per the ICC-ES acceptance criteria AC308 and the ACI test standard ACI 355.4 . Data derived from this testing is given in an ICC-ESR . Pre-calculated values for V sa are given in the ICC-ESR steel design tables . Although parameters such as A se , V and f uta may be given in the ICC-ESR , PROFIS Engineering uses the pre-calculated V sa
-values to define the nominal steel strength in shear . Adhesive anchor ICC-ESR V sa
-values are specific to static load conditions . An additional reduction factor designated “ α V , seis
” is applied to the V sa
-value when calculating nominal steel strength in shear for seismic load conditions . α V , seis
-values are derived from AC308 / ACI 355.4 testing , and will be given in the ICC-ESR steel design tables . In lieu of Equation ( 17.5.1.2b ), the Equations section of the PROFIS Engineering report for an adhesive anchor system references “ V sa
= ICC-ESR value ” when modeling static load conditions and “ V sa , eq = ICC-ESR value ” when modeling seismic load conditions , where V sa , eq = α V , seis
V sa
. One exception to this nomenclature is with respect to the HIT-HY 200 adhesive system . The Equations section of the PROFIS Engineering report for HIT-HY 200 steel strength parameters references “ V sa
= ( 0.6 A se , V f uta
)” when modeling static load conditions and “ V sa = α V , seis
( 0.6 A se , V f uta
)” when modeling seismic load conditions , where ( 0.6
A se , V f uta
) corresponds to the V sa
-value given in the ICC-ESR steel design tables .
Anchor elements in the PROFIS Engineering adhesive anchor portfolio are as follows :
• Threaded rods
• Reinforcing bars
• Internally threaded inserts
• HIT-Z and HIT-Z-R threaded rods ( HIT-HY 200 only )
Reference the adhesive anchor system ICC-ESR for V sa values specific to an anchor element .
Reference the Calculations and Results section of the report for more information on V sa and V sa , eq
.
Reference the Variables section of the report for more information on the parameters A se , V and f uta
.
297 NORTH AMERICAN PROFIS ENGINEERING ANCHORING TO CONCRETE DESIGN GUIDE — ACI 318-14 Provisions