Tank Foundation Ringwall Design Page 1 of 9

Tank Foundation Ringwall Design - English

API 650

Input Parameters

Tank Information

Tank ID : RIVER WATER TANK

Tank Foundation Type : Mechanically Anchored

Input Unit System : English
Weight Input Method : Direct Weight Input

Design Code : US Code

Overturning Check Requirement : Overturning Check Required

Sliding Check Requirement : Sliding Check Required

Footing Geometry

Footing Centreline Diameter (Fd) : 606.000 in

Minimum Ringwall Width (Fwmin) : 30.000 in

Maximum Ringwall Width (Fwmax) : 30.000 in

Ringwall Height (Fh): : 42.000 in

Compacted Granular Fill (Ds) : 6.000 in

Width Dimension Increment (widinc) : 12.000 in

Bottom of Footing Elevation (BOF) : 1200.000 in

Tank Properties

Internal Tank Diameter (Di) : 600.000 in

Height of Tank Shell (Hs) : 432.000 in
Average Thickness of Tank (Tavg) : 0.375 in
Thickness of Tank Bottom (Tbot) : 0.375 in
Thickness of Tank Roof (Trf) : 0.375 in
Yield Strength of Bottom Plate (Fby) : 36.000 kip/in2
Elastic Modulus of Tank Shell (Es) : 29000.000 kip/in2
Tank Material Density : 0.00028 kip/in^3
Insulation Thickness (Tins) : 0.000 in

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Fluid Weight

Product Empty Weight (Wtempt) : 0.000 kip

Product Operating Weight (Wtoper) : 4166.000 kip

Product Test Weight (Wttest) : 4166.000 kip

Miscellaneous Loading

Internal Operating Pressure ( oper) : 0.001 kip/in^2

Internal Test Pressure ( test) : 0.001 kip/in^2
Minimum Roof Snow Load (Snow) : 0.000 kip/in^2
Snow Importance Factor (Isnow) : 1.000
Miscellaneous Dead Load (Misc) : 0.000 kip/in^2
Miscellaneous Live Load (Live) : 0.000 kip/in^2
% Miscellaneous Weight for Attachments (Misc_wt): : 5.0 %

Design Parameters

Soil Properties

Allowable Bearing Pressure (SBC) : 0.017 kip/in2

Soil Density (Ysoil) : 0.000 kip/in^3
Coefficient of Friction ( ) : 0.400
Soil Bearing Multiplication Factor for Wind and Siesmic Load Case
: 1.330
(SBF)
Lateral Earth Pressure Coefficient (k_lateral) : 0.500
Overturning Safety Ratio (OTR) : 1.500
Sliding Safety Ratio (SLR) : 2.000

Material Properties

Concrete Compressive Strength (fc) : 4.000 kip/in2

Concrete Density (Yc) : 0.000 kip/in^3
Concrete Cover (cc) : 3.000 in
Yield Strength of Rebar (fy) : 60.000 kip/in2
Minimum Rebar Size : ∅5
Maximum Rebar Size : ∅11
Minimum Stirrup Size : ∅4
Maximum Stirrup Size : ∅11
Minimum Stirrup Spacing : 6.000 in
Strirrup Spacing Increment : 1.000 in

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Calculations

External Diameter of Tank (D) = Di + 2.Tavg : 600.750 in

Miscellaneous attachment weight is considered for Weight of Tank Shell and Roof
Weight of Tank Shell (Ws) : 90.976 kip
Weight of Tank Roof (Wr) : 31.648 kip
Weight of Tank Floor (Wf) : 30.141 kip
Total Snow Load (Wsnow) : 39.366 kip
Total External Dead Load (Wdead) : 9.841 kip
Total Live Load (Wlive) : 0.000 kip
Tank Empty Weight (Wempty) = Ws + Wr + Wf : 152.766 kip

Wind Load Calculations

Wind Load Type : Direct User Input

Wind Shear Force : 0.000 kip

Wind Moment : 0.000 kip-in

Partial Wind % : 50.000

Seismic Load

Seismic Load Type : Program Generated

Spectral Response Acceleration at Short Periods (Ss) : 0.157
Spectral Response Acceleration at Period of 1 sec (S1): 0.059
Factor to adjust 5% damping to 1/2% damping (K): 1.500
Long-Period Transition Period (TL): 8.000 sec
Seismic Use Group (SUG): II
Site Class (Class): D
Impulsive Response Modification Factor (Rwi): 3.500
Convective Response Modification Factor (Rwc): 2.000
Importance Factor (Ieq): 1.250

Seismic Load Calculations

Design Spectral Response Acc. Parameter at Short

0.167 - per ASCE 7-05 11.4.3
Period (SDS) :
Design Spectral Response Acc. Parameter at 1 sec
0.094 - per ASCE 7-05 11.4.4
(SD1) :
TO : 0.113 s - per ASCE 7-05 11.4.7
TS : 0.564 s - per ASCE 7-05 11.4.7
DH : 1.472 - Ratio of Diameter to Liquid Height

:
0.581 - Per API 650 E.4.5.2-c

: 4.110 s - Convective Period API 650 E4.5.2-b

0.060 - Impulsive Spectral Acceleration

:
Parameter API 650 E.4.6.1-1

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0.022 - Convective Spectral Acceleration

: Parameter API 650 E.4.6.1-1

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Seismic Load Calculation per API 650 Section E

Operating
Parameter Test Condition Unit
Condition
Impulsive Product
Seismic Weight 2793.992 2793.992 kip
(Wi)
Convectve Product
Seismic Weight 1391.680 1391.680 kip
(Wc)
Impulsive
Component Base 176.244 176.244 kip
Shear (Vi)
Convective
Component Base 29.965 29.965 kip
Shear (Vc)
Total Design Base
178.773 178.773 kip
Shear (V)
Impulsive Fluid
153.000 153.000 in
Force Height (Xi)
Convective Fluid
269.316 269.316 in
Force Height (Xc)
Ringwall Moment
28717.661 28717.661 kip-in
(Mrw)

Vertical Seismic Force Coefficient

= 0.040 Vertical Seismic per API E.6.1.3

Freeboard Check

Vertical Seismic
Available Freeboard Height, 24.000in
per API E.6.1.3
per API650
E.7.2-2, E.7.2-
Af = 0.042
3, E.7.2-4 &
E.7.2-5
per API650
12.588in
E.7.2-1
Freeboard Requirement, 8.812in

FR< FB, Hence Freeboard Requirement Is Satisfied

Overturning Effect of Seismic Forces (Slab Moment Calculation)

Overtuning Seismic Forces per API 650 Section E

Operating
Parameter Test Condition Unit
Condition
Slab Moment
Impulsive Fluid 253.151 253.151 in
Height (Xis)
Slab Moment
Convective Fluid 294.861 294.861 in
Height (Xcs)
Slab Moment
45168.920 45168.920 kip-in
(Ms)

Internal Pressure Calculation

Total force due to internal pressure :

= 283.451kip

= 283.451kip

Internal pressure around the perimeter :

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= 0.150kip/in

= 0.150kip/in

Load Combination
Allowable Stress Design Factors (Service Loads)
External Internal Test
LC SWF SBF Empty Operating Test Snow Live Wind Earthquake
Pressure Pressure Pressure
101 1.00 1.00 1.00 1.00 . . 1.00 . . . . .
102 1.00 1.00 1.00 . 1.00 . . . . . . .
103 1.00 1.00 1.00 . . . 0.40 . . . 1.00 .
104 1.00 1.00 1.00 1.00 . . 0.40 . . . 1.00 .
105 1.00 1.00 1.00 . . 0.40 . . . . 1.00 .
106 1.00 1.00 1.00 1.00 . 0.40 . . . . 1.00 .
107 1.00 1.00 1.00 1.00 . 0.40 . . . 1.00 . .
108 1.00 1.00 1.00 1.00 . 0.40 . . 1.00 . . .
109 1.00 1.00 1.00 . . 1.00 . . . 0.40 . .
110 1.00 1.00 1.00 . . 1.00 . . 0.40 . . .
111 1.00 1.00 1.00 1.00 . 1.00 . . . 0.40 . .
112 1.00 1.00 1.00 1.00 . 1.00 . . 0.40 . . .
113 1.00 1.00 1.00 1.00 . . 0.40 . 0.10 . . 1.00
114 1.00 1.00 1.00 1.00 . . . . 0.10 . . 1.00

Ultimate Stress Design Factors

EXternal Internal Test
LC SWF SBF Empty Operating Test Snow Live Wind Earthquake
Pressure Pressure Pressure
201 1.00 1.00 1.40 . . . 0.56 . . . . .
202 1.00 1.00 1.00 1.40 . . 0.56 . . . . .
203 1.00 1.00 1.20 . . 0.64 0.48 . 0.50 1.60 . .
204 1.00 1.00 1.00 1.20 . 0.64 0.48 . 0.50 1.60 . .
205 1.00 1.00 1.20 . . . . . 1.60 1.00 . .
206 1.00 1.00 1.00 1.20 . . . . 1.60 1.00 . .
207 1.00 1.00 1.20 . . . . . 0.50 1.00 1.60 .
208 1.00 1.00 1.00 1.20 . . . . 0.50 1.00 1.60 .
209 1.00 1.00 1.20 . . . . . 0.20 1.00 . 1.00
210 1.00 1.00 1.00 1.20 . . . . 0.20 1.00 . 1.00
211 1.00 1.00 0.90 . . . 0.64 . . . 1.60 .
212 1.00 1.00 1.00 0.90 . . 0.64 . . . 1.60 .
213 1.00 1.00 0.90 . . . 0.64 . . . . 1.00
214 1.00 1.00 1.00 0.90 . . 0.64 . . . . 1.00
215 1.00 1.00 1.00 . 0.90 . 0.64 . . . 1.60 .

Applied Loads At Top of Ringwall- Service Stress Level

Axial Shear Moment
LC
(kip) (kip) (kip-in)
101 -4612.058 0.000 0.000
102 -4328.607 0.000 0.000
103 -275.987 0.000 0.000
104 -4441.987 0.000 0.000
105 -162.607 0.000 0.000
106 -4328.607 0.000 0.000
107 -4328.607 0.000 0.000
108 -4367.973 0.000 0.000
109 -162.607 0.000 0.000
110 -178.353 0.000 0.000
111 -4328.607 0.000 0.000
112 -4344.353 0.000 0.000
113 -4445.924 178.773 28717.661
114 -4332.544 178.773 28717.661

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Applied Loads At Top of Ringwall- Strength Level

Axial Shear Moment
LC
(kip) (kip) (kip-in)
201 -386.382 0.000 0.000
202 -6153.740 0.000 0.000
203 -350.868 0.000 0.000
204 -5317.546 0.000 0.000
205 -258.114 0.000 0.000
206 -5224.792 0.000 0.000
207 -214.811 0.000 0.000
208 -5181.490 0.000 0.000
209 -203.002 178.773 28717.661
210 -5169.680 178.773 28717.661
211 -327.755 0.000 0.000
212 -4093.416 0.000 0.000
213 -327.755 178.773 28717.661
214 -4093.416 178.773 28717.661
215 -4093.416 0.000 0.000

Design Calculations

Tank Stability

Tank Shell and Roof Weight Per Unit Length = = 0.065 kip/in

Snow load per unit length = = 0.021 kip/in

Liquid Weight on Tank Floor = 0.015 kip/in^2

Internal Pressure = 283.451 kip/in^2
Liquid Density per unit Length = 0.150 kip/in

Factored Ring wall moment, = 28717.661 kip-in

Anchor Bolt Tension Force per API 650 E.6.2.1.2-2, PAB = 4.701
Anchor bolts should comply to ACI 318 Appendix D, API 650 E.6.2.1.2, API 650 E.7.1.2

Internal Soil Bearing Check

(Below Tank Floor)

Maximum Internal soil bearing check (below tank bottom plate) for dead load case

= 0.016 kip/in^2

Maximum Internal soil bearing check (below tank bottom plate) for seismic load case

= 0.012 kip/in^2

Governing Internal Soil Bearing

SBint = max(SBint_dl,SBint_eq) = 0.016 kip/in^2

Governing Load Case No for Internal Soil Bearing: 101

SBint < SBC, Hence Internal Soil Bearing is OK

Ringwall Soil Bearing

Governing Load Case For Ringwall Soil Bearing Check: 108

Allowable Ring Wall Soil Bearing Check: 0.017kip/in^2

Maximum Ring Wall Soil Bearing : 0.012kip/in^2

SBring < SBC, Hence Ringwall Soil Bearing is OK

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Ringwall Dimension After Soil Bearing Check

Footing Width (FW) : 30.000 in
Footing Depth (Fh) : 42.000 in
Entire Foundation Self Weight
Wfdn_total : 207.455 kip

Overturning Check
Governing Load Case for Overturning Check : 114
Governing Overturning Moment, Ms : 45168.920 kip-in

Seismic Load Case Overturning Safety Ratio =

Other Load Case Overturning Safety Ratio =

Overturning Safety Ratio = 28.350

Factor of safety against overturning
Load Case No. Resistant Overturning FOS Required Overturning FOS
101 30.670 1.500
102 28.785 1.500
103 N/A 1.500
104 29.539 1.500
105 N/A 1.500
106 28.785 1.500
107 28.785 1.500
108 29.047 1.500
109 N/A 1.500
110 N/A 1.500
111 28.785 1.500
112 28.890 1.500
113 29.092 1.500
114 28.350 1.500
Tank Foundation Passes Overturning Check

Sliding Check
Governing Load Case For Sliding Check : 114
Total Shear : 178.773 kip

Seismic Load Case Sliding Safety Ratio =

Other Load Case Sliding Safety Ratio =

Sliding Safety Ratio : 9.539

Factor of safety against sliding
Load Case No. Resistant Sliding FOS Required Sliding FOS
101 N/A 2.000
102 N/A 2.000
103 N/A 2.000
104 N/A 2.000
105 N/A 2.000
106 N/A 2.000
107 N/A 2.000
108 N/A 2.000
109 N/A 2.000
110 N/A 2.000
111 N/A 2.000
112 N/A 2.000
113 9.788 2.000
114 9.539 2.000
Tank Foundation Passes In Sliding Check

Reinforcement Calculations
Hoop Steel

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Unfactored Hoop Tension : 101.909 kip

per PIP STE03020 5.6.3.3

Area of Hoop steel required = = 3.020 in^2

Per PIP STE03020 5.6.3.4 and API 650 B.4.2.3

Twist Steel
Twist Moment Lever Arms
z_1 : 3.000 in
z_2 : 9.000 in
PT = Total Load on Tank
WP = Product load on Tank Bottom
E = Linear Earthquake Load on Ringwall
L = Distance from tank shell to inside edge of ringwall
Twist Moment in Ringwall
: 2.450 kip-in

per PIP STE03020 5.6.4.6

Mu : 743.276 kip-in
Mimimum Rebar Size : #5
Maximum Rebar Size : #11
Minimum Stirrup Size : #4
Maximum Stirrup Size : #11

: 38.188 in

: 0.019 kip/in

: 0.00032

Area of Twist steel required, = 0.361 in^2

Per ACI318-11, 10.5.1,
= 3.819 in^2

Per ACI318-11, 10.5.3,

= 0.482 in^2

Twist steel is required both on top and bottom of ringwall

Total Area of Reinforcement Required
: 3.983 in^2

Stirrup Design

Minimum stirrup requirement = = 0.216 in^2 /ft each face

Minimum Strirrup Spacing = 6.000 in

Maximum Stirrup requirement = 18.000 in
Vertical Steel Requirement Per STE03020
= 0.216 in^2 /ft
5.6.6.1a
Horizontal Steel Requirement Per
= 2.520 in^2
STE03020 5.6.6.1b
Reinforcement Bars Along The Section of
Provide #5 - 14
Ringwall
Provide #4 @ 10.00in o.c. Two Legged Stirrups

Print Calculation Sheet

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