|
ψ ed , N
= 0.7 + 0.3
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c a , min ≤ 1 . 0
1.5h ef
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17.6 . 2.4.1 Modification factor for edge effects for single anchors or anchor groups loaded in tension , ψ ed , N
, shall be determined by ( a ) or ( b ).
( a ) If c a , min ≥ 1.5h ef
, then ψ ed , N = 1.0 ( 17.6.2.4.1a )
( b ) If c a , min < 1.5h ef
, then ψ ed , N = 0.7 + 0.3
c a , min ( 17 . 6 . 2 . 4 . 1b )
1.5h ef
17.6 . 2.1 Nominal concrete breakout strength in tension , N cb of a single anchor or N cbg of an anchor group satisfying 17.5.1.3.1 , shall be calculated by ( a ) or ( b ), respectively :
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When calculating the nominal concrete pryout strength in shear ( V cp or V cpg
), the parameter ψ ed , N is a modification factor that accounts for fixed edge distances less than 1.5h ef
, where hef corresponds to the effective embedment depth that has been selected for the anchor being modeled in PROFIS Engineering . The illustration below shows how the assumed area of influence with respect to pryout ( A Nc
) would be defined for an anchoring application being modeled with two fixed edges ( c a1 and c a2 ) that are both less than 1.5h ef
, and with c a1 being less than c a2
.
The smallest edge distance ( c a1 ) corresponds to the parameter c a , min
, and would be used to calculate the modification factor ψ ed , N .
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( a ) For a single anchor |
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N cb
= A Nc ψ ed , N ψ c , N ψ cp , N
N b
( 17.6.2.1a )
A Nc0
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( b ) For an anchor group |
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N cbg
= A Nc ψ ec , N ψ ed , N ψ c , N ψ cp , N
N b
( 17.6.2.1b )
A Nc0
|
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…………………………………………. |
ψ ed , N
= 0.7 + 0.3 ( c a1 / 1.5h ef
)
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It is important to understand that “ ψ ed , N
” calculated for concrete breakout failure in tension is not necessarily the same as “ ψ ed , N
” calculated for concrete pryout failure in shear since the number of anchors in tension may not be the same as the number of anchors in shear .
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Reference the Variables section of the PROFIS Engineering report for more information on the following parameters :
c a , min
: parameter for the smallest fixed edge being modeled .
h ef
: parameter for anchor effective embedment depth .
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Reference the Calculations section of the PROFIS Engineering report for more information on ψ ed , N when calculating concrete pryout strength . |