










VERTICAL VESSEL CIRCULAR PATTERN ANCHOR BOLT DESIGN



Result Summary










Anchor Rod Embedment, Spacing and Edge Distance




Warn


Overall





ratio

=

0.73

OK


Seismic Design





Tension

=


NA







Shear

=


NA



Design Code Reference










Anchor bolt design based on









Code Abbreviation

ACI 31811 Building Code Requirements for Structural Concrete and Commentary Appendix D

ACI 31811

PIP STE03350 Vertical Vessel Foundation Design Guide2008

PIP STE03350

PIP STE05121 Anchor Bolt Design Guide2006

PIP STE05121

ASCE Anchorage Design for Petrochemical Facilities2013

ASCE Anchorage










Code Reference

Design Option






Select anchor bolt design code







Select design using or not
using anchor reinforcement






Concrete Mat or Pedestal Input







D_{p}=159.36
S_{p}=66.01
D_{bc}=144.00
c_{1}=7.68
c_{2}=19.29
c_{4}=19.29
A_{NC}



Select concrete mat shape


=






Octagon mat facetoface distance

D_{p}

=


[in]






No of anchor bolt

N_{ab}

=






Anchor bolt bolt circle diameter

D_{bc}

=


[in]






Anchor Bolt Forces Input











Anchor bolt loads input by


=


Factored moment at base of vessel

M_{u}

=


[kipft]







Factored shear at base of vessel

V_{u}

=


[kips]







Empty vessel weight

D_{e}

=


[kips]






Anchor Bolt Data Input








Concrete strength

f'_{c}

=


[ksi]




Anchor bolt material


=







Anchor tensile strength

f_{uta}

=

58.0

[ksi]





ACI 31811




Anchor is ductile steel element




D.1

Anchor bolt diameter

d_{a}

=


[in]






Anchor bolt has sleeve


=








Anchor bolt head type


=






Anchor effective cross section area

A_{se}

=

1.410

[in^{2}]





Anchor bolt head bearing area

A_{brg}

=


[in^{2}]



Anchor bolt 1/8" (3mm) corrosion allowance

=

















PIP STE05121

Anchor bolt embedment depth

h_{ef}

=


[in]

18.00


Warn


Page A 1 Table 1

Pedestal height

h_{a}

=


[in]

17.50


OK



Supplementary reinforcement









ACI 31811

For tension


=


Condition B




D.4.3 (c)

For shear

Y_{c,v}

=


Condition A




D.6.2.7


Concrete cracking


=






D.5.2.6, D5.3.6, D.6.2.7


Provide builtup grout pad ?


=







D.6.1.3

Seismic Input









ACI 31811

Seismic design category SDC >= C


=







D.3.3.1


Design Basis and Assumptions


The design of circular pattern anchor bolt group uses the Method
2 Sawcut with h_{ef}’ and Neutral Axis at Center as stated in
the following references
1. ASCE Anchorage Design for Petrochemical Facilities  2013 Example
2 Step 5(c) on Page 145
2. ASCE 2010 Structural Congress  Concrete Breakout Strength in Tension for Vertical
Vessel Anchorage in Octagon Pedestals
The design of circular pattern anchor bolt group is simplified as design of a single
anchor bolt with 3 side free edges sawcut at midway between adjacent anchors. The
simplified design method uses the following assumptions
1. The moment is resisted only by the anchor bolt group and it does not take into
account the contribution of concrete compression
force against base plate in the moment equilibrium
2. The neutral axis is not shifted and is located at center of vessel
3. It does not consider strain compatibility between the concrete and steel elements
which comprise the anchorage.
4. In the assumed 3 side free edges sawcut model, when anchor is located less than
1.5h_{ef} from three or more edges, the reduced
h_{ef}' is used to calculate concrete projected failure
area A_{NC}
The utilization ratio of simplified method used in this calculation is conservative
compared to the accurate but more complex approach. The detail comparison and analysis
of this simplified method is addressed in reference 2 above.



CONCLUSION









View Detail Calc

Anchor Rod Embedment, Spacing and Edge Distance




Warn


Overall

ratio

=

0.73

OK


Tension






Anchor Rod Tensile Resistance

ratio

=

0.48

OK


Concrete Tensile Breakout Resistance

ratio

=

0.73

OK


Anchor Pullout Resistance

ratio

=

0.23

OK


Side Blowout Resistance

ratio

=

0.00

NA


Shear






Anchor Rod Shear Resistance

ratio

=

0.00

OK


Concrete Shear Breakout Resistance  Perpendicular To Edge

ratio

=

0.00

OK


Concrete Shear Breakout Resistance  Parallel To Edge

ratio

=

0.00

OK


Concrete Pryout Shear Resistance

ratio

=

0.00

OK


Tension Shear Interaction






Tension Shear Interaction

ratio

=

0.00

OK








Seismic Design





ACI 31811

Tension

Not Applicable




NA

D.3.3.4

Seismic SDC< C or E<=0.2U , additional seismic requirements in D.3.3.4.3 is NOT required, as per D.3.3.1 & D.3.3.4.1













Shear

Not Applicable




NA

D.3.3.5

Seismic SDC< C or E<=0.2U , additional seismic requirements in D.3.3.5.3 is NOT required, as per D.3.3.1 & D.3.3.5.1




CACULATION











Single Anchor Bolt Tensile and Shear Load




PIP STE03350

Factored compression at top of concrete pedestal

P_{u}

=

M_{u} /0.667 D_{bc} + 0.9 D_{e} /2

=

210.10

[kips]

Section 4.6.2 Eq 5

Factored frictional resistance

f V_{f}

=

f m P_{u} = 0.75 x 0.55 x P_{u}

=

86.67

[kips]

Section 4.6.2 Eq 6



>

V_{u}

shear load taken by the friction

Section 4.6.2 Eq 7

Factored single bolt tensile load

N_{ua}

=

4 M_{u }/ (N_{ab} x D_{bc})  0.9 D_{e} / N_{ab}

=

29.54

[kips]

Section 4.6.1 Eq 4

Factored single bolt shear load

V_{ua}

=

shear load taken by the friction

=

0.00

[kips]




Single Anchor Bolt Edge Distances and Projected Failure Area





Anchor bolt edge distance

c_{1}

=

(D_{p}  D_{bc}) / 2

=

7.68

[in]



c_{3}

=

D_{p}  c_{1}

=

151.68

[in]



c_{2}

=


=

19.29

[in]



c_{4}

=

c_{2}



=

19.29

[in]

ACI 31811

Effective embedment depth

h_{ef}'

=


=

12.86

[in]

D.5.2.3

Octagon side edge length

S_{p}

=

D_{p} / (1+√2)

=

66.01

[in]


Octagon shape conc mat area

A_{p}

=


=

21038

[in^{2}]


Projected conc failure area

A_{NC}

=


=

1026

[in^{2}]













