PROFIS ENGINEERING shear load acts on a single anchor: V cb = A vc A vc0 ψ ed, V ψ c, V ψ h, V V b ACI 318−19 Eq. shear load acts on an anchor group: V cbg = A vc A vc0 ψ ec, V ψ ed, V ψ c, V ψ h, V V b ACI 318−19 Eq.
The parameters shown in the above equations are shown in Table 1 [ 3 ]. Table 1.
Parameter Description ACI 318-19 Equation A Vc projected concrete failure area reference Fig. R17.7.2.1b
A Vc0
ψ ec, V idealized concrete failure area for a single anchor
modification factor for eccentric load
A Vc0 = 4.5 c a1 2 ψ ec, V =
1
Eq.( 17.7.2.1.3)
1 + e ′ V 1.5c a1
Eq.( 17.7.2.3.1) modification factor for edge distance( c a2) c a2 ψ ed, V ψ ed, V = 0.7 + 0.3 Eq.( 17.7.2.4.1b)
1.5c when c a2 < 1.5c a1 a1
modification factor for uncracked concrete, ψ c, V or cracked concrete with supplementary reinforcement reference Section 17.7.2.5 modification factor for concrete thickness( h a) ψ h, V ψ h, V = 1. 5c a1
Eq.( 17.7.2.4.1b) h when h a < 1.5c a1 a
V b basic concrete breakout strength( anchors not rigidly attached to fixture) basic concrete breakout strength( anchors rigidly attached to fixture) basic concrete breakout strength( limiting equation)
V b = 7 l e d a
0.2
V b = 8 l e d a
0.2 d a λ a f c ′ c a1
1.5 d a λ a f c ′ c a1
1.5
V b = 9λ a f c ′ c a1
1.5
Eq.( 17.7.2.2.1a)
Eq.( 17.7.2.2.2)
Eq.( 17.7.2.2.1b)
PROFIS Engineering modifies the V cb( g) equations to include an additional ψ-factor( ψ parallel, V) for shear load acting either perpendicular to, or parallel to, an edge. Reference ACI 318-19 Section 17.7.2.1( c).
single anchor: V cb = A vc A vc0 ψ ed, V ψ c, V ψ h, V ψ parallel, V V b modified ACI 318−19 Eq. anchor group: V cbg = A vc A vc0 ψ ec, V ψ ed, V ψ c, V ψ h, V ψ parallel, V V b modified ACI 318−19 Eq.
where: ψ parallel, V = 1.0 if shear load acts perpendicular to a fixed edge ψ parallel, V = 2.0 if shear load acts parallel to a fixed edge
The parameter c a1 referenced in Table 1 [ 3 ] corresponds to the distance in the direction of the applied shear load from the center of a single anchor, or from a line through a row / column of anchors, to a fixed concrete edge. When an anchorage consists of multiple anchor rows / columns, V cb( g) can be calculated using a c a1 value from a specific row / column as illustrated in Figure 1. As previously noted, ACI 318-19 defines three“ cases” to calculate V cb( g) for an anchorage consisting of multiple anchor rows / columns. These cases are denoted:“ Case 1”,“ Case 2” and“ Case 3”.
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