PROFIS ENGINEERING REPORT TENSION LOAD
Bond Failure Mode
Equations N ag
Equations ACI 318-14 Chapter 17 Provision Comments for PROFIS Engineering
N ag
= A Na ψ ec , Na ψ ed , Na ψ cp , Na
N ba
A Na0
17.4.5.1 The nominal bond strength in tension , …….. N ag of a group of adhesive anchors , shall not exceed : ( b ) For a group of adhesive anchors
N ag
= A Na ψ ec , Na ψ ed , Na ψ cp , Na
N ba
( 17.4.5.1b )
A Na0
ACI 318 anchoring-to-concrete provisions for the nominal bond strength of a group of adhesive anchors ( N ag
) require calculation of various modification factors corresponding to area of influence ( A Na
/ A Na0 ), eccentricity ( ψ ec , Na
), edge distance
( ψ ed , Na ), and splitting ( ψ cp , Na
); and then multiplying these factors by what is termed the “ basic bond strength in tension ” ( N ba
) to obtain a “ nominal bond strength in tension ” ( N ag
).
Reference the Calculations section of the PROFIS Engineering report for more information on the following parameters :
A Na
: Area of influence for anchors in tension
A Na0
: Area of influence for single anchor in tension
ψ ec , Na
: Tension modification factor for eccentricity
ψ ed , Na
: Tension modification factor for edge distance
ψ cp , Na
: Modification factor for splitting
N ba
: Basic bond strength in tension
Reference the Results section of the PROFIS Engineering report for more information on N ag
.
Equations ϕN ag
Equations ACI 318-14 Chapter 17 Provision Comments for PROFIS Engineering
ϕN ag
≥ 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 Bond Strength in Tension
Single Anchor
ϕN ag
≥ N ua
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 ag corresponds to the design bond strength for a group of anchors in tension . The parameter N ua corresponds to the factored tension load acting on the anchor group . If ϕ N ag
> N ua for the application being modeled , the provisions of Section 17.3.1.1 are satisfied for bond failure .
Reference the Results section of the PROFIS Engineering report for more information on the following parameters :
N ag
: Nominal bond strength in tension
ϕ bond
: Strength reduction factor for bond failure
ϕ seismic
: Strength reduction factor for seismic tension
ϕN ag
: Design bond strength in tension
N ua
: Factored load acting on anchors in tension
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 .
10 NORTH AMERICAN PROFIS ENGINEERING ANCHORING TO CONCRETE DESIGN GUIDE — ACI 318-14 Provisions