PART 3 TENSION LOAD
Side-Face Blowout Failure
Equation ϕN sbg
Equation ACI 318-14 Chapter 17 Provision Comments for PROFIS Engineering
ϕN sbg
≥ N ua
17.3.1.1 The design of anchors shall be in accordance with Table 17.3.1.1 . In addition , the design of anchors shall satisfy 17.2.3 for earthquake loading and 17.3.1.2 for adhesive anchors subject to sustained tensile loading .
Table 17.3.1.1 Failure Mode Side-Face Blowout Strength in Tension
Anchor Group
ϕN sbg
≥ N ua
PROFIS Engineering uses the designation “ N ua , edge
” to denote the factored load acting on anchors in tension nearest the fixed edge being considered for side-face blowout .
In Illustration # 1 below , the total factored tension load acting on all six anchors is equals “ N ua ”. In
Illustration # 2 , the portion of N ua acting on the anchors in red , i . e . the anchors in tension nearest the fixed edge being considered for side-face blowout , equals “ N ua , edge
”.
Illustration # 1
ACI 318-14 strength design provisions for tension check a calculated design strength ( ϕN N
) against a factored tension load ( N ua
). The parameter ϕN sbg corresponds to the design side-face blowout strength for a group of anchors in tension . When performing side-face blowout calculations , the parameter N ua corresponds to the factored tension load acting on the anchors nearest the fixed edge being considered for side-face blowout . PROFIS Engineering designates this parameter “ N ua , edge
”.
If ϕN sbg ≥ N ua
, edge for the application being modeled , the provisions of Section 17.3.1.1 are satisfied for side-face blowout failure .
Reference the Results section of the PROFIS Engineering report for more information on the following parameters :
N sbg
: Nominal side-face blowout strength in tension
ϕ concrete
: Strength reduction factor for side-face blowout failure
ϕ seismic
: Strength reduction factor for seismic tension
N ua , edge
: Factored load acting on anchors in tension nearest the fixed edge being considered for side-face blowout
A summary of calculated tension design strength versus the factored tension load for each tension failure mode relevant to the application is given in Part 3 Tension Load of the PROFIS Engineering report .
Illustration # 2
106 NORTH AMERICAN PROFIS ENGINEERING ANCHORING TO CONCRETE DESIGN GUIDE — ACI 318-14 Provisions