|
ψ ec , N
=
|
1
1 + 2e ́N
3h ef
|
≤ 1.0 |
17.4.2.4 The modification factor for anchor groups loaded eccentrically in tension , ψ ec , N shall be calculated as
ψ ec , N
=
1
1 + 2e ́N
( 17.4.2.4 )
|
ψ ec , N is a modification factor that is used to account for a resultant tension load that is eccentric with respect to the centroid of anchors that are loaded in tension .
ψ ec , N is only considered when calculating the nominal concrete breakout strength in tension for an anchor group ( N cbg
).
Reference the Variables section of the PROFIS Engineering report for more information on the following parameters :
|
3h ef
|
e c1 , N
: Parameter for tension eccentricity with respect to the x direction
|
|||
|
but ψ ec , N shall not be taken greater than 1.0 . If the loading on an anchor group is such that only some anchors are in tension , only those anchors that are in tension shall be considered when determining the eccentricity e ́N for use in Eq . ( 17.4.2.4 ) and for the calculation of N cbg according to
Eq . ( 17.4.2.1b ).
In the case where eccentric loading exists about two axes , the modification factor , ψ ec , N
, shall be calculated for each axis individually and the product of these factors used as ψ ec , N in Eq . ( 17.4.2.1b ).
|
e c2 , N
: Parameter for tension eccentricity with respect to the y direction
h ef
: Parameter for anchor effective embedment depth .
Reference the Calculations section of the PROFIS Engineering report for more information on the following parameters :
ψ ec1 , N
: Modification factor for tension eccentricity with respect to the x direction
|
|||
|
ψ ec2 , N
: Modification factor for tension eccentricity with respect to the y direction
|
|
ψ ed , N
= 0.7 + 0.3
|
c a , min ≤1 . 0
1.5h ef
|
17.4 . 2.5 The modification factor for edge effects for single anchors or anchor groups loaded in tension , ψ ed , N
, shall be calculated as
If c a , min
≥ 1.5h ef , then ψ ed , Na
= 1.0 ( 17.4.2.5a )
If c a , min < 1.5h ef
, then ψ ed , Na = 0.7 + 0.3
c a , min ( 17 . 4 . 5 . 4b )
c Na
|
ψ ed , N is a modification factor that is used to account 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 ( 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 .
|
|
ψ ed , N
= 0.7 + 0.3 ( c a1 / 1.5h ef
)
|
|||
Reference the Variables section of the PROFIS Engineering report for more information on the following parameters : |