PROFIS ENGINEERING REPORT TENSION LOAD
Bond Failure Mode
Equations A Na
Equations ACI 318-14 Chapter 17 Provision Comments for PROFIS Engineering
A Na
17.4.5.1 …….. A Na is the projected influence area of a single adhesive anchor or group of adhesive anchors that shall be approximated as a rectilinear area that projects outward a distance c Na from the centerline of the adhesive anchor , or in the case of a group of adhesive anchors , from a line through a row of adjacent adhesive anchors ……..
A Na is a modification factor that accounts for the area of influence assumed to develop in concrete , with respect to bond failure , when a tension load is applied to a single adhesive anchor or a group of adhesive anchors . A Na is calculated with the edge conditions and anchor spacing that have been input into the PROFIS Engineering model . The geometry for A Na is defined by projected distances from the anchors that are in tension . The maximum projected distance from an anchor that is considered when calculating A Na is limited to c Na , where c Na is defined by Equation ( 17.4.5.1d ) in Section 17.4.5.1 . Therefore , the maximum edge distance parameter used to calculate A Na equals c Na and the maximum spacing parameter used to calculate A Na equals 2.0c Na
. The figure below illustrates how A Na is calculated for a group of four anchors in tension with fixed edge distances equal to c a1 and c a2 , and spacing parameters equal to s 1 and s 2
. Note that the maximum edge distance parameter used to calculate A Na equals c Na
. Anchors spaced greater than 2.0c Na from one another would not be considered to act as a group with respect to that spacing .
A Na
= ( c a1 + s 1
+ c Na ) ( c a2
+ s 2 + c Na
) where : c a1 and c a2 are < c Na s 1 and s 2 are < 2.0c Na
Reference the Equations and Calculations section of the PROFIS Engineering report for more information on c Na
.
Reference the Calculations section of the PROFIS Engineering report for more information on A Na
.
11 NORTH AMERICAN PROFIS ENGINEERING ANCHORING TO CONCRETE DESIGN GUIDE — ACI 318-14 Provisions