PART 3 TENSION LOAD
Sustained Tension Load — Bond Strength
Results N ua , s
Results ACI 318-14 Chapter 17 Provision Comments for PROFIS Engineering
N ua , s
17.3.1.2 For the design of adhesive anchors to resist sustained tension loads , in addition to 17.3.1.1 , Eq . ( 17.3.1.2 ) shall be satisfied .
0.55 ϕN ba ≥ N ua , s
( 17.3.1.2 )
Excerpt from PROFIS Engineering report showing sustained tension load ( N ua , s
) corresponding to the highest loaded anchor . 3 Tension Load
Load Capacity Utilization Status Steel Strength 3000 14550 21 OK Bond Strength 12000 17088 71 OK Sustained Tension Load Bond Strength * 250 8899 29 OK Concrete Breakout Failure ** 12000 14562 83 OK
* highest loaded anchor ** anchor group ( anchors in tenson )
If a single anchor in tension is being modeled , PROFIS Engineering calculates the parameter ϕN pn
, and checks this value against either ( a ) the factored tension load acting on the anchor , which has been calculated using the loads input via the Load Engine , ( b ) the factored tension load acting on the anchor , which has been calculated using the loads imported from a spreadsheet or ( c ) the factored tension load acting on the anchor , which has been calculated using the loads input in the matrix on the main screen . The value for N ua shown in the report corresponds to the factored tension load determined to be acting on the anchor .
If a group of anchors in tension is being modeled , PROFIS Engineering calculates the parameter
ϕN pn
, and checks this value against either ( a ) the total factored tension load acting on the anchor group , which has been calculated using the loads input via the Load Engine , ( b ) the total factored tension load acting on the anchor group , which has been calculated using the loads imported from a spreadsheet or ( c ) the total factored tension load acting on the anchor group , which has been calculated using the loads input in the matrix on the main screen . The value for N ua shown in the report corresponds to the total factored tension load determined to be acting on the anchor group .
The provisions given in ACI 318-14 Section 17.3.1.2 are used to perform a check for adhesive anchors subjected to sustained tension loads . The check consists of calculating a capacity ( 0.55ϕN ba
), and comparing it to the highest ( factored ) sustained tension load ( N ua , s
) acting on a single anchor within the anchor group .
ACI 318-14 anchoring-to-concrete provisions require a design strength to be checked against a factored load . The design strength calculated with respect to sustained tension load is defined in Eq . ( 17.3.1.2 ) as 0.55ϕN ba
. This design strength is checked against the parameter N ua , s
, which corresponds to the highest factored sustained tension load acting on a single anchor within the anchor group . If 0.55ϕN ba
≥ N ua , s
, the provisions for considering sustained tension load have been satisfied per Section 17.3.1.1 .
N ua , s is a factored tension load . 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 a sustained tension load . The software only performs a sustained tension load check per Eq . ( 17.3.1.2 ) if a sustained load ( s ) has been input via one of the load input functionalities .
If a single adhesive anchor in tension is being modeled , PROFIS Engineering calculates the parameter 0.55ϕN ba for a single anchor , and checks this value against either ( a ) the sustained factored tension load acting on the anchor , which has been calculated using the loads input via the Load Engine , ( b ) the sustained factored tension load acting on the anchor , which has been calculated using the loads imported from a spreadsheet or ( c ) the sustained factored tension load acting on the anchor , which has been calculated using the loads input in the matrix on the main screen . The value for N ua , s shown in the report corresponds to the sustained factored tension load determined to be acting on the anchor .
If a group of adhesive anchors in tension is being modeled , PROFIS Engineering calculates the parameter 0.55ϕN ba for a single anchor , and checks this value against either ( a ) the highest sustained factored tension load acting on the anchor group , which has been calculated using the loads input via the Load Engine , ( b ) the highest sustained factored tension load acting on the anchor group , which has been calculated using the loads imported from a spreadsheet or ( c ) the highest sustained factored tension load acting on the anchor group , which has been calculated using the loads input in the matrix on the main screen . The value for
N ua , s shown in the report corresponds to the highest sustained factored tension load determined to be acting on an individual anchor within the anchor group that is in tension .
Reference the Equations and Results section of the PROFIS Engineering report for more information on the parameter 0.55ϕN b a .
156 NORTH AMERICAN PROFIS ENGINEERING ANCHORING TO CONCRETE DESIGN GUIDE — ACI 318-14 Provisions