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STUD ANCHOR DESIGN Combined Tension and Shear

Result Summary                  
Anchor Rod Embedment, Spacing and Edge Distance       OK  
Overall         ratio = 0.80 OK  
Seismic Design         Tension =   OK  
          Shear =   OK  

Design Code Reference                  
Welded stud design based on                 Code Abbreviation
ACI 318-11 Building Code Requirements for Structural Concrete and Commentary Appendix D ACI 318-11
PIP STE05121 Anchor Bolt Design Guide-2006 PIP STE05121
                Code Reference
Welded Stud Data                    
Factored tensile force Nu = [kips]      
Factored shear force Vu = [kips]      
Concrete strength f'c = [ksi]    
Welded stud material   =          
Anchor tensile strength futa = 65.0 [ksi]         ACI 318-11
      Anchor is ductile steel element       D.1
Welded stud diameter da  = [in]            
Anchor effective cross section area Ase = 0.442 [in2]        
Welded stud head bearing area Abrg = [in2]        
                PIP STE05121
Welded stud edge distance c1 c1 = [in] 4.50   OK   Page A -1 Table 1
Welded stud edge distance c2 c2 = [in] 4.50   OK    
Welded stud edge distance c3 c3 = [in] 4.50   OK    
Welded stud edge distance c4 c4 = [in] 4.50   OK    
                   
Welded stud embedment depth hef = [in]         ACI 318-11
ci ≥ 1.5hef for at least two edges to avoid reducing of hef when Nu > 0   OK   D.5.2.3
Welded stud adjusted hef for design hef = [in] 9.00   OK   D.5.2.3
Concrete thickness ha = [in] 15.00   OK    
                  PIP STE05121
Outermost bolt line spacing s1 s1 = [in] 3.00   OK   Page A -1 Table 1
Outermost bolt line spacing s2 s2 = [in] 3.00   OK    
                   
 
                   
For conc shear breakout check use                  
Number of anchor at bolt line 1 n1 =            
Number of anchor at bolt line 2 n2 =            
                   
For conc side-face blowout check use                
No of welded stud along width edge nbw =            
No of welded stud along depth edge nbd =          
                 
Total no of welded stud n =          
No of welded stud carrying tension nt =            
No of welded stud carrying shear ns =            
                   
Supplementary reinforcement                 ACI 318-11
        For tension   = Condition A       D.4.3 (c)
        For shear Yc,v = Condition A       D.6.2.7
                  ACI 318-11
Provide built-up grout pad ?   =           D.6.1.3
Concrete cracking   =         D.5.2.6, D5.3.6, D.6.2.7
                  ACI 318-11
Seismic design category SDC >= C   =           D.3.3.1
Welded stud load E <= 0.2U Tensile =   Shear =   D.3.3.4.1 & D.3.3.5.1
Welded stud satisfies opion Tensile = Shear = D.3.3.4.3 & D.3.3.5.3
                   
Strength reduction factors                 ACI 318-11
Anchor reinforcement fs = 0.75           D.5.2.9 & D.6.2.9
Anchor rod - ductile steel ft,s = 0.75   fv,s = 0.65   D.4.3 (a)
Concrete ft,c = 0.75  Cdn-A fv,c = 0.75  Cdn-A D.4.3 (c)

CONCLUSION
                 
Anchor Rod Embedment, Spacing and Edge Distance       OK  
Overall ratio = 0.80 OK  
Tension          
Anchor Rod Tensile Resistance ratio = 0.17 OK  
Concrete Tensile Breakout Resistance ratio = 0.35 OK  
Anchor Pullout Resistance ratio = 0.22 OK  
Side Blowout Resistance ratio = 0.00 NA  
Shear          
Anchor Rod Shear Resistance ratio = 0.20 OK  
Concrete Shear Breakout Resistance - Perpendicular To Edge ratio = 0.62 OK  
Concrete Shear Breakout Resistance - Parallel To Edge ratio = 0.14 OK  
Concrete Pryout Shear Resistance ratio = 0.19 OK  
Tension Shear Interaction          
Tension Shear Interaction ratio = 0.80 OK  
           
Seismic Design         ACI 318-11
Tension Applicable       OK D.3.3.4
Seismic SDC>=C and E>0.2U , Option D is selected to satisfy additional seismic requirements as per D.3.3.4.3    
                   
Shear Applicable       OK D.3.3.5
Seismic SDC>=C and E>0.2U , Option C is selected to satisfy additional seismic requirements as per D.3.3.5.3    

Assumptions ACI 318-11
1. Concrete is cracked D.5.2.6, D5.3.6, D.6.2.7
2. Condition A - supplementary reinforcement provided D.4.3 (c)
3. Load combinations shall be per ACI 318-11 9.2 D.4.3
4. Tensile load acts through center of bolt group Yec,N =1.0 D.5.2.4
5. Shear load acts through center of bolt group Yec,V =1.0 D.6.2.5

CACULATION                  
Anchor Rod Tensile Resistance                 ACI 318-11
  f t,s Nsa = f t,s nt Ase futa = 86.19 [kips] D.5.1.2 (D-2)
  ratio = 0.17 > Nu OK  
               
Concrete Tensile Breakout Resistance       ACI 318-11
  Nb = 24 l √fc hef1.5  if hef <11" or hef>25" = 72.57 [kips] D.5.2.2 (D-6)
      16 l √fc hef(5/3)  if 11"≤ hef ≤25"       D.5.2.2 (D-7)
Projected conc failure area 1.5 hef =   = 18.00 [in]  
  ANC = [s1+min(c1,1.5hef)+min(c3,1.5hef)]x = 1444.0 [in2]  
      [s2+min(c2,1.5hef)+min(c4,1.5hef)]        
  ANCO = 9 hef2 = 1296.0 [in2] D.5.2.1 (D-5)
  ANC = min ( ANC, nt ANCO ) = 1444.0 [in2] D.5.2.1
Min edge distance cmin = min( c1, c2, c3, c4 ) = 15.00 [in]  
Eccentricity effects Ψec,N = 1.0  for no eccentric load       D.5.2.4
Edge effects Ψed,N = min[ (0.7+0.3cmin/1.5hef), 1.0 ] = 0.95   D.5.2.5
Concrete cracking Ψc,N = 1.00  for cracked concrete       D.5.2.6
Concrete splitting Ψcp,N = 1.00  for cast-in anchor       D.5.2.7
               
Concrete breakout resistance ftcNcbg =
ftc  ANC Ψec,N Ψed,N Ψc,N Ψcp,N Nb
ANCO
= 57.61 [kips] D.5.2.1 (D-4)
               
Seismic design strength reduction   = x 0.75 applicable = 43.21 [kips] D.3.3.4.4
  ratio = 0.35 > Nu OK  
               
Anchor Pullout Resistance             ACI 318-11
Single bolt pullout resistance N p = 8 Abrg fc' = 32.66 [kips] D.5.3.4 (D-14)
  ft,c Npn = f t,c nt Ψc,p Np = 91.44 [kips] D.5.3.1 (D-13)
  Ψc,p = 1.00  for cracked concrete       D.5.3.6
  f t,c = 0.70 pullout strength is always Condition B D.4.3(c)
Seismic design strength reduction   = x 0.75 applicable = 68.58 [kips] D.3.3.4.4
  ratio = 0.22 > Nu OK  
               
Side Blowout Resistance              
Failure Along Pedestal Width Edge             ACI 318-11
Tensile load carried by anchors close to edge which may cause side-face blowout        
along pedestal width edge Nbuw = Nu x nbw / nt = 7.50 [kips] RD.5.4.2
  c = min ( c1, c3 ) = 15.00 [in]  
  s = s2 = 5.00 [in]  
Check if side blowout applicable hef = 12.00 [in]          
    < 2.5c side bowout is NOT applicable D.5.4.1
               
Failure Along Pedestal Depth Edge             ACI 318-11
Tensile load carried by anchors close to edge which may cause side-face blowout        
along pedestal depth edge Nbud = Nu x nbd / nt = 7.50 [kips] RD.5.4.2
  c = min ( c2, c4 ) = 15.00 [in]  
  s = s1 = 5.00 [in]  
Check if side blowout applicable hef = 12.00 [in]          
    < 2.5c side bowout is NOT applicable D.5.4.1
               
Group side blowout resistance ftc Nsbg = = 0.00 [kips]  
               
Govern Tensile Resistance Nr = min ( f Nsa, f Ncbg, f Npn, f Nsbg ) 43.21 [kips]  
               
Anchor Rod Shear Resistance             ACI 318-11
  f v,sVsa = f v,s ns Ase futa = 74.70 [kips] D.6.1.2 (a) (D-28)
Reduction due to built-up grout pad   = x 1.0 , not applicable = 74.70 [kips] D.6.1.3
  ratio = 0.20 > Vu OK  
               
Conc. Shear Breakout Resistance - Perpendicular To Edge       ACI 318-11
Only Case 2 needs to be considered when anchors are rigidly connected to the attachment Fig. RD.6.2.1(b) notes
This applies to welded stud case so only Mode 2 is considered for shear checking in Case 2
               
Mode 2 Failure cone at back anchors        
               
 
               
Bolt edge distance ca1 = c1 + s1 = 20.00 [in] ACI 318-11
Limiting ca1 when anchors are influenced by 3 or more edges = Yes   D.6.2.4
Bolt edge distance - adjusted ca1 = ca1 needs to be adjusted = 16.67 [in] D.6.2.4
  c2 =   = 15.00 [in]  
  1.5ca1 =   = 25.00 [in] ACI 318-11
  Avc = [min(c2,1.5ca1)+ s2 + min(c4,1.5ca1)]x = 675.0 [in2] D.6.2.1
      min(1.5ca1, ha)       ACI 318-11
  Avco = 4.5ca12 = 1250.0 [in2] D.6.2.1 (D-32)
  Avc = min ( Avc, n2 Avco ) = 675.0 [in2] D.6.2.1
  le = min( 8da , hef ) = 6.00 [in] D.6.2.2
  Vb1 = = 45.08 [kips] D.6.2.2 (D-33)
  Vb2 = = 44.16 [kips] D.6.2.2 (D-34)
  Vb = min( Vb1 , Vb2 ) = 44.16 [kips] D.6.2.2
Eccentricity effects Ψec,v = 1.0 shear acts through center of group       D.6.2.5
Edge effects Ψed,v = min[ (0.7+0.3c2/1.5ca1), 1.0 ] = 0.88   D.6.2.6
Concrete cracking Ψc,v = concrete is cracked = 1.20   D.6.2.7
Member thickness Ψh,v = max[ (sqrt(1.5ca1 / ha) , 1.0 ] = 1.29   D.6.2.8
              ACI 318-11
Conc shear breakout resistance Vcbg =
fv,c  Avc Ψec,v Ψed,v Ψc,v Ψh,v Vb
Avco
= 24.38 [kips] D.6.2.1 (D-31)
  ratio = 0.62 > Vu OK  
               
Conc. Shear Breakout Resistance - Parallel To Edge        
               
 
              ACI 318-11
Only Case 2 needs to be considered when anchors are rigidly connected to the attachment Fig. RD.6.2.1(b) notes
This applies to welded stud case so only Mode 2 is considered for shear checking in Case 2
   
Mode 2 Shear taken evenly by back welded studs, strength check against 0.5 x Vu  
               
Bolt edge distance ca1 = min(c2 , c4) = 15.00 [in] ACI 318-11
Limiting ca1 when anchors are influenced by 3 or more edges = No   D.6.2.4
Bolt edge distance - adjusted ca1 = ca1 needs NOT to be adjusted = 15.00 [in] D.6.2.4
  1.5ca1 =   = 22.50 [in] ACI 318-11
  Avc = [min(s1+c1,1.5ca1) +min(c3,1.5ca1)]x = 637.5 [in2] D.6.2.1
      min(1.5ca1, ha)       ACI 318-11
  Avco = 4.5ca12 = 1012.5 [in2] D.6.2.1 (D-32)
  Avc = min ( Avc, nbd Avco ) = 637.5 [in2] D.6.2.1
  le = min( 8da , hef ) = 6.00 [in] D.6.2.2
  Vb1 = = 38.49 [kips] D.6.2.2 (D-33)
  Vb2 = = 37.70 [kips] D.6.2.2 (D-34)
  Vb = min( Vb1 , Vb2 ) = 37.70 [kips] D.6.2.2
Eccentricity effects Ψec,v = 1.0 shear acts through center of group       D.6.2.5
Edge effects Ψed,v =   = 1.00   D.6.2.1 (c)
Concrete cracking Ψc,v = concrete is cracked = 1.20   D.6.2.7
Member thickness Ψh,v = max[ (sqrt(1.5ca1 / ha) , 1.0 ] = 1.22   D.6.2.8
              ACI 318-11
Conc shear breakout resistance Vcbg-p =
2xfv,c  Avc Ψec,v Ψed,v Ψc,v Ψh,v Vb
Avco
= 104.67 [kips] D.6.2.1 (D-31)
      x 2 side       D.6.2.1 (c)
  ratio = 0.14 > Vu OK  
               
Conc. Pryout Shear Resistance             ACI 318-11
  kcp = 2.0       D.6.3.1
Factored shear pryout resistance fv,cVcpg = fv,c kcp Ncbg = 107.54 [kips] D.6.3.1 (D-41)
  f v,c = 0.7  pryout strength is always Condition B   D.4.3 (c)
               
Seismic design strength reduction   = x 0.75 applicable = 80.66 [kips] D.3.3.4.4
  ratio = 0.19 > Vu OK  
               
Govern Shear Resistance Vr = min ( fVsa , fVcbg , fVcbg-p , fVcpg ) = 24.38 [kips]  
               
Tension Shear Interaction             ACI 318-11
Check if Nu >0.2f Nn and Vu >0.2f Vn = Yes       D.7.1 & D.7.2
      Nu / f Nn + Vu / f Vn = 0.96   D.7.3 (D-42)
  ratio = 0.80 < 1.2 OK  
               
Seismic Design              
Tension     Applicable     OK  
Option D is selected. ACI 318-11
User has to ensure that the tensile load Nu user input above includes the seismic load E, with E increased
by multiplying overstrength factor Ωo
D.3.3.4.3(d)
                   
Seismic SDC>=C and E>0.2U , Option D is selected to satisfy additional seismic requirements as per D.3.3.4.3    
               
Shear     Applicable     OK  
Option C is selected.             ACI 318-11
User has to ensure that the shear load Vu user input above includes the seismic load E, with E increased
by multiplying overstrength factor Ωo
D.3.3.5.3(c)
               
Seismic SDC>=C and E>0.2U , Option C is selected to satisfy additional seismic requirements as per D.3.3.5.3    
                   

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