Step 01 : Load Data
Tensile force R= 332 Kip
Theta 28.15 Degree
Horizontal Component Fx= 292.7 Kip
Vertical Component Fy= 156.6 Kip
Step 02 : Design Considaration
Anchor type used Post Installed anchor
Supplimentary reinforcement Not Provided
Side Face blowout due to tension Not considered. See (RD. 5.4)
This is applicable for undercut cast in anchor
This type of anchor not considered here
Tension Design strength controlled by Steel tensile strenght
Concrete Breakout
Concreete Side face blowout (Not Considered)
Concrete pullout
Shear design strength controled by Steel shear failure
Cocrete prayout
Concrete breakout
*** side face blow out in D 5.4 not considered which has been explained above
Page 01
Anchor Failure modes
Step 03 : Anchor Specification
Aanchor Bolt =ASTM F1554 Grade 55 Material ductile steel
Specified tensile strength of anchor steel, futa= 75000 psi
Specified yield strength of anchor steel, fya= 55000 psi
Compressive strength of base material, f'c= 3005 psi
Step 04 : Edge distance and spacing of bolts
The minimum edge distance for post-installed anchors should be based on the greater of the minimum
cover requirements in ACI 318 Section 7.7 or minimum edge distance requirements for the products
as determined by tests in accordance with ACI 355.2 (Table A.3), and should not be less than two times
the maximum aggregate size. (Reference D 8.3)
Considering aggregate size as 3/4 inch edge distance =2*3/4=1.5 inch
Edge distance in the dirrection of shear has been considered as 4hef (Reference D8.6)
Spacing of anchors has been taken as 6do (Reference D8.1) d0=is the diameter of anchor
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Step 05 :Design for Tension
5.1: Steel design strength under tensile loading
considering 0.750 inch dia of bolt (5/8inch or 16mm dia bolt)
Nsa= *Ase*futa, where, Ase=Effective shear stress area (Ref: ACI 355.3r-11, Table A.3)
Ase= 0.334 Nsa= 18.7875 Kip for single bolt.
5.2: Cocrete Breakout strength under tensile loading
Anchors are attached with beam and column.
Minimum dimension of column/beam 10 inch
Minimum hef =2/3 of minimum dimension or (minimum dimension-4 inch)
Considering both case hef = 7 inch
Ca (minimum edge distance) has been taken a 3.5 inch
Ca<1.5hef s1=6d0= 4.5 inch s2=6d0= 4.5 inch
Anc=(ca1+s1+1.5hef)*(ca2+s2+1.5hef)=(3+3.75+1.5*6)*(3+3.75+1.5* 342.25 Sq inch
Anc0=9*hef^2= 441 sq inch
Page 03
Nb=17*sqrt(2255)*6^1.5 = 17259.1 D 5.2.2
Since the bracing is loaded diagonaly so all the bolts are subjected to shear. So effect of ececntricity can
neglected
ecN= 1
Camin<1.5hef
edN= 0.8
Considering cracking in service load levels
c,N= 1
Page 04
Considering cracking in service load levels
cp,N= 1
Ncbg= 10715.52 Pound
10.72 Kip
= 0.55
For category2 condition B
So Ncb 5.89 Kip
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5.3: Cocrete Pullout strength under tensile loading
Nominal pullout strength for post installed anchors, Npn=cpNp
5 9617
8 19463
when hef= 7
Np= 16181 lb (Ref: ACI 355.3r-11, Table A.3)
So Design pullout strength,Np= 8899.55 Pound
So, Design Tension Force of single anchor Npn= 12.46 Kip
5.4: Cocrete Side Face blowout under tensile loading (Not considered)
So Tension strength
Steel tensile strength nsa= 18.7875 Kip
Concrete Break out strength Ncb 5.89 Kip Governs
Concrete Pullout Strength Np= 12.46 Kip
Step 06 :Design for Shear
6.1: Steel strength of anchor in shear
Nominal strength in shear of a single anchor,Vsa=0.6*Ase*futa
But futa should not be greater than 1.9fya or 125000psi
so, futa= 75000 psi
Ase= 0.334 Sq inch (Ref: ACI 355.3r-11, Table A.3)
= 0.65 for shear
so vsa= 9769.5 Pound
9.77 Kip
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6.2:Concrete breakout of anchor in shear
Since the bracing is loaded diagonaly so all the bolts are subjected to shear. So effect of ececntricity can
neglected
ec,v= 1
Ca2 3.5 inch
Ca1 3.5 inch
so Ca2<1.5Ca1
ed,v= 0.9
Avc0=4.5Ca^2
Avc0= 55.125 Sq inch
Ca2<1.5Ca1
Avc=1.5Ca1*(1.5Ca1+1.5Ca2)
Avc= 55.125 Sq inch
Page 07
c,v= 1
le=hef= 7 inch or le< 8do 6
so le = 6 inch
Ca 3.5 inch
d0 0.750 inch
f'c 3005 Psi
Vb 3298.154
= 0.55
For category2 condition B
Vcbg= 2968.339 pound
2.97 Kip
Page 08
6.3:Concrete prayout strenght of anchor in shear
hef=6 inch > 2.5 inch
Kcp= 2
Ncbg 10.72 Kip
Vcpg= 21.43 Kip
So Tension strength
Steel shear strength Vsa= 9.77 Kip
Concrete Break out strength Vcbg= 2.97 Kip Governs
Concrete Prayout Strength Vcpg= 21.43 Kip
Step 07 :Calculation of bolt arrangemets
Horizontal component of load Fx= 292.7 Kip
Vertical component of load Fy= 156.6 kip
Anchor bolt tension capacity = 5.89 Kip
Anchor bolt Shear capacity = 2.97 kip
So placing 34 bolts in horizontal dirrection
and placing 34 bolts in vertical dirrection
Horizontal capacity= 301.3 kip which is OK
Vertical capacity = 301.3 kip which is OK
Page 09
Step 08 :Interaction of tensile and shear forces
Load on a single anchor in Horizontal face
Shear Vua=(Horizontal component - no of vertical boltsX tension capacity)/No of horizontal bolts
Tension Nua=(Vertical component - no of vertical boltsX shear capacity)/No of horizontal bolts
Vua= 2.7 Kip
Nua= 1.64 Kip
Nua/Nn+Vua/Vn= 1.193055
