PROFIS Design Guide - AC 318-19 July 2022 | Page 306

2.0 SHEAR

2.4 Stand-off Failure Mode
Results V ua
Results ACI 318-19 Chapter 17 Provision Comments for PROFIS Engineering
V ua
17.5 . 2 For each applicable factored load combination , design strength of anchors shall satisfy the criteria in Table 17.5.2 .
Excerpt from ACI 318-19 Table 17.5.2 showing provisions for shear calculations .
Table 17.5.2 — Design strength requirements of anchors
Failure Mode Single Anchor
Individual anchor in a Group
Steel strength in shear
( 17.7.1 )
ϕV sa
≥ V ua
ϕV sa
≥ V ua , i
Anchor Group
Anchors as a group
ACI 318-19 strength design provisions for steel failure in shear require calculation of a nominal steel strength ( V sa
). The nominal strength is multiplied by a strength reduction factor ( ф-factor ) to obtain a design strength ( фV sa
).
Design strength is checked against a factored shear load , defined by the parameter “ V ua
”. Chapter 2 in ACI 318-19 gives the following definitions for the factored shear load parameter “ Vua ”.
• V ua
= factored shear force applied to single anchor or group of anchors ( lb )
• V ua , i
= factored shear force applied to most highly stressed anchor in a group of anchors ( lb )
• V ua , g = total factored shear force applied to anchor group ( lb )
Concrete breakout strength 11 shear ( 17.7.2 )
Concrete pryout strength in shear ( 17.7.3 )
ϕV cb
≥ V ua
ϕV cp
≥ V ua
ϕV cbg
≥ V ua , g
ϕV cpg
≥ V ua , g
The design steel strength for a single anchor in shear ( фV sa
) calculated per Table 17.5.2 is checked against the factored shear load acting on the anchor , which is designated “ V ua
” in Table 17.5.2 . If фV sa ≥ V ua
, the provisions for considering steel failure in shear have been satisfied per Table 17.5.2 .
If an application consists of a group of anchors in shear , V sa is calculated for a single anchor , and the design strength ( фV sa
) is checked against the highest individually loaded anchor in shear , which is designated “ V ua , i
” in Table 17.5.2 . If фV sa ≥ V ua , i
, the provisions for considering steel failure in shear have been satisfied per Table 17.5.2 .
The PROFIS Engineering report section for steel failure in shear uses the generic designation “ V ua
” to reference either the only shear load acting on an anchor in shear , or the highest shear load acting on an individual anchor within an anchor group in shear . The PROFIS Engineering Load Engine permits users to input service loads that will then be factored per IBC factored load equations . Users can also import factored load combinations via a spreadsheet , or input factored load combinations directly on the main screen . PROFIS Engineering users are responsible for inputting shear loads . The software only performs shear load checks per Table 17.5.2 if shear loads have been input via one of the load input functionalities .
If a single anchor in shear is being modeled , PROFIS Engineering calculates the parameter фV sa
, and checks this value against either ( a ) the factored shear load acting on the anchor , which has been calculated using the loads input via the Load Engine , ( b ) the factored shear load acting on the anchor , which has been calculated using the loads imported from a spreadsheet or ( c ) the factored shear load acting on the anchor , which has been calculated using the loads input in the matrix on the main screen . The value for
V ua shown in the report corresponds to the factored shear load determined to be acting on the anchor .
If a group of anchors in shear is being modeled , PROFIS Engineering calculates the parameter фV sa
, and checks this value against either ( a ) the highest factored shear load acting on an individual anchor in the anchor group , which has been calculated using the loads input via the Load Engine , ( b ) the highest factored shear load acting on an individual anchor in the anchor group , which has been calculated using the loads imported from a spreadsheet or ( c ) the highest factored shear load acting on an individual anchor in the anchor group , which has been calculated using the loads input in the matrix on the main screen . The value for V ua shown in the report corresponds to the highest factored shear load acting on an individual anchor in the anchor group .
Reference the Equations and Calculations section of the PROFIS Engineering report for more information on the parameter фV sa
.
306 NORTH AMERICAN PROFIS ENGINEERING ANCHORING TO CONCRETE DESIGN GUIDE — ACI 318-19 Provisions