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Daftar Pustaka
1. Bai, Yong. 2001. “Pipelines and Risers”. Amsterdam: Elsevier Science.
2. Dalrymple, Dean. 1991. “Water Wave Mechanics for Engineers and Scientist”. New Jersey: World
Scientific.
3. Ellenberger, Philip. 2005. “Piping Systems & Pipeline”. McGraw‐Hill Profesional Engineering.
4. Guo, Boyun. 2005. “Offshore Pipelines”. Massachussets: Elsevier Inc.
5. Heryanto, Julius. 2008. “Desain dan Analisis Struktur Pipa Bawah Laut”. Institut Teknologi Bandung.
6. McAllister, E.W.. 2002. “Pipeline Rules of Thumb Handbook”. Gulf Profesional Publishing.
7. Mouselli, A.H. 1985. “Offshore Pipelines Design, Analysis, and Method”. Oklahoma: Penn Well
Books.
8. Nakazawa, Kazuto. 1980. “Soil Mechanic and Foundation Engineering”. Pradnya Paramitha.
9. Palmer, Andrew C. and King, Roger A. 2004. “Subsea Pipeline Engineering”. PennWell Corporation.
10. Sam Kannappan, P.E. 1985. “Pipe Stress Analysis”. John Wiley & Sons.
11. Veritas Offshore Technology and Services A/S. April 1981. “DNV 1981 Rules for Submarine Pipelines
Systems”. Norway: DNV Publisher.
12. Veritas Offshore Technology and Services A/S. March 2002. “DNV RP F105 Free Spanning Pipelines”.
Norway: DNV Publisher.
13. Veritas Offshore Technology and Services A/S. August 2005. “DNV RP E305 On‐Bottom Stability
Design of Submarine Pipelines ”. Norway: DNV Publisher.
DESIGN DATA
Pipe OD , d = inches= mm
Concrete grade = kg/cm2
Tensile strength of steel , fy = kg/cm2
Density of concrete = kg/m3
Density of soil , γ = kg/m3
Angle of friction , φ = 0 Backfill materialφ 0 = 0 original soil
Cohession of soil, Ca = kg/m2 original soil
Fx = kgFy = kgFz = kgMx = kgmMy = kgmM
0
30.0
32.00812.8
2400
1754200
1800
200
radians0.520.61=35.0
= radians
2.150
00
20
4957
PERENCANAAN PIPA DAN EXPANSION SPOOL PADA PIPA PENYALUR SPM
ANCHOR BLOCK CALCULATION
Mz = kgm= m H2 = m
Assumed length of concrete block , L1 = m L2 = m= m
Depth of pipe from top of concrete , db = mDepth of pipe from top of soil , hp = m
Hence volume of concrete block = m3
Volume due to pipe = m3
Hence effective volume of concrete block = -= m3
PLAN
SECTION X-X SETION Z-Z
2.7
L1
H1
0.41
Assumed total height of concrete block , H1
0.41
hp
1.00
0.800.80
centre line of pipe - X
1.102.40
0
H2centre line of pipe
B
Assumed total width of concrete block , B
B
2.00
2.72
0.40
2.31
L2
Z
db
L2
H1
PERENCANAAN PIPA DAN EXPANSION SPOOL PADA PIPA PENYALUR SPM
ANCHOR BLOCK CALCULATION
Total block weight , W = m3 x kg/m3
W = kg
Total soil weight above the block , Ws = (( B x L ) x ( hp - db ) + (L2-L1) x ( hp - db + H1 )) x γ
Ws = kg
CHECK FOR UPLIFT
Vertical uplift force from pipe, Fv = ( Fy + sqrt (( Mx/B)2 + (Mz/L)2))
= kg
Factor of safety against uplift = /
= > Hence OK
PASSIVE EARTH PRESSURE
Pp = γ x H x Kp
553.2278
10.00
5760
2400
5532
0 2
2.0
10.00
55322.305
where , Kp = ( 1 - sin φ ) / ( 1 + sin φ ) =
Pp = γ x (hp-db+H2) x Kp
= kg/cm2
Fp = 0.5 x Pp x (B x H2 - 0.25 x pi x OD^2)= kg
CHECK FOR SLIDING
Coefficient of friction , μ 0 = tan ( φ0 ) =
Resistance to sliding = ( 0.7 x Ca x ( L2 x B ) + ( μ0 x ( W + Ws - Fy ))
= ( x x ( x x )
= kg
Factor of safety against sliding = ( Resistance to sliding ) / {(sqrt ( Fx2 + Fz
2 )) - Fp }
= /
= > Hence OK
CHECK FOR OVERTUNING
Height of centre of pipe from base , Hm = m
Overtuning moment due to pipe load = ( sqrt (Fx2 + Fz
2 ) x Hm ) + My
= kgm
Stabilizing moment due to block weight & passive pressure is given as= ((W - Fy ) x (L2 - x) )
= kgm
Factor of safety against overtuning = /
= > Hence OK
20
13550.73
6586.8
4259.98
697
6586.80
1.546
9.311
1.5
0.7
829
11292.32.40 2.00 ) + (
0.58
0.58
0.27
1455.375
2.0
13550.73
0.29
1455
PERENCANAAN PIPA DAN EXPANSION SPOOL PADA PIPA PENYALUR SPM
ANCHOR BLOCK CALCULATION
x
I
0.80
1.11
m
1.10
0.90
0.41
0.221.20
X V *X
y
V*Y
0.80
=
0.70 1.5361.728
2 21.11
x1 y1 =3.2642 2
= 1.20 m=
2.40
1.44 1.20 0.15
x1
2.72
1.28V Y
3.264
y1
CHECK FOR BEARING CAPACITY
Ultimate Bearing capacity = t/m2
Actual bearing pressure = ( W - Fy ) / ( area of bottom anchor block )
= t/m2 < Ultimate Bearing capacity
REINFORCEMENT
Reinforcement Data :fy = t/m2 Dia. of bar = = cm2
fc' = t/m2 fy rebar = t/m2
Shear Check :
Effect. thickness of conc. block t = m
Shear Force Vu = tVu
Vc = 0.85 x 0.53 x fc'0.5 x B x d = t Vu < Vc OK !
- Concrete block rebar :
Ld = ( L1 - .075 ) = m
= of gross section area
b' = m (analysis per 1 m width)
= 0.15% * Ld * b' = cm2/m
Rebar : D16mm - mm
m0.412.72
x1 y12.72
1.20 m
0.725
L1
4.957
27.33
10.88
0.15% L2
150
Amin
Amin
Hence OK
0.73
3.46
2.4 D16mm 1.986
1
hf
H1
1750 42000
15
PERENCANAAN PIPA DAN EXPANSION SPOOL PADA PIPA PENYALUR SPM
ANCHOR BLOCK CALCULATION
- Punching Shear :
Vc = bo * d * [ φ * ( 0.34 ) * sqrt( fc' ) ]
bo = 2 * [(a + d) + b ] = m
d = hf - cover = m
Vc = MN Vu = V = MN
Thickness of footing slab is OK
- Flexture Rebar for footing slab :
fmax = t/m2
s1 = (L2-L1)/2 = m
Mu = 1/2 * fmax * s12
= t.m
b' = m (analysis per 1 m width)
hf
6.05
==
fmax
s1
L2
0 0028
L1 + d
15.000
1.629
* [ 1 sqrt( 1 2 * R / ( 0 85 * f ' ) ) ]
0.030
L1
0.8
>
0.225
= 111 5470.85 * fc't/ 2
1
R =Mu
4.800
ρuse = As = ρuse * d * b' = cm2/m
Rebar : D16mm - mm
== 0.0028* [ 1 - sqrt( 1 - 2 Ru / ( 0.85 fc ) ) ]
0.013fy (MN/m2) fy 600 + fy
( β ) * 600 =0.75 *0.85 * fc' *
1.4=
= 111.547φ * b' * d2 fy
0.003401 7.653
200
ρmin = 0.003401 ρmax =
ct/m2 ρRu =
BUCKLING AND COLLAPSEDURING INSTALLATION
Condition : Installation stage is assumed as the most critical time that buckling andcollapse could occur. At installation stage, there is no internal pressure tocounteract hydrostatic head. Pressure design is assumed as zero pressure, socalculation will produce a conservative result.
K = C
INPUT DATA:
Maximum Water Depth dmax 81.2ft:=
Minimum Water Depth dmin 0ft:= *
Seawater Density ρsw 64lb
ft3
:=
Maximum External Pressure Pe_max ρsw g⋅ dmax⋅:=
Pe_max 36.089 psi=
Minimum External Pressure Pe_min ρsw g⋅ dmin⋅:= *Pe_min 0=
Outside Diameter D 32in:=
Wall Thickness t 0.45in:=
Internal Diameter ID D 2t−:= *ID 31.1 in=
Material Grade : API 5L X‐52
Spesified Minimum Yield Stress SMYS 52000psi:=
Steel Density ρs 490.1lb
ft3
:=
Poissons Ratio υ 0.3:=
Modulus Elasticity E 3.01 107psi⋅:= *
Coefficient of Thermal Expansion α 1.17 105−
⋅ C1−
:= *Permissible Usage Factor ηxp 0.96:=
Permissible Usage Factor ηyp 0.82:=
Operating Data :
Design Pressure Pd 0psi:= *Contain Density ρcont 0lb ft
3−⋅:= *
Max. Operating Temp Ti 82.222C:=
Installation temp Tins 25C:=
CALCULATIONS:
Axial Stress
Axial Stress Due To End Effect σend Pd
π
4ID2
π D2ID2−( )⋅
4
⋅:= *
σend 0=
Axial Stress Due To Poisson Effect σpoissons υ−Pd ID⋅ Pe_min D⋅−
2t⎛⎜⎝
⎞⎟⎠
⋅:= *
σpoissons 0=
Longitudinal / axial strain byinternal pressure σp σend σpoissons+:= *
σp 0=
Thermal stress
σt E α⋅ Ti Tins−( )⋅:= * σt 2.015 104
× psi=
Total Axial Stress σtot σp σt+:= *σtot 2.015 10
4× psi=
Buckling Check :
Longitudinal StressDue To Axial Component σx_N σtot:=
σx_N 2.015 104
× psi=Longitudinal StressDue To Moment σx_M 0psi:= *Longitudinal Stress σx σx_N σx_M+:= *
σx 2.015 104
× psi=
Critical Longitudinal Stress (N Act Alone)
σxcrn_N SMYSD
t20<if
SMYS 1 0.001D
t20−⎛⎜
⎝⎞⎟⎠
−⎡⎢⎣
⎤⎥⎦
⋅ 20D
t< 100<if
:= *
σxcrn_N 4.934 104
× psi=
σxcr_M SMYS 1.35 0.0045D
t⋅−⎛⎜
⎝⎞⎟⎠
⋅:= * σxcr_M 5.356 104
× psi=
Critical Longitudinal Stress
σxcrσx_N
σxσxcrn_N⋅
σx_M
σxσxcr_M⋅+:= *
σxcr 4.934 104
× psi=
Hoop Stress σyPd Pe_max−
2 t⋅D⋅:=
σy 1.283− 103
× psi=
Hoop Stress Elastic σyE Et
D t−⎛⎜⎝
⎞⎟⎠
2⋅:= *
σyE 6.123 103
× psi=Critical Hoop Stress
σycr σyE σyE2
3SMYS⋅≤if
SMYS 11
3
2SMYS
3 σyE⋅⎛⎜⎝
⎞⎟⎠
2⋅−
⎡⎢⎣
⎤⎥⎦
⋅2
3
σyE
SMYS<if
:= *
σycr 6.123 103
× psi=
α 1300
D
t
σy
σycr⋅⎛
⎜⎜⎝
⎞⎟⎟⎠
+:= α 0.116=
ifσx
ηxp σxcr⋅⎛⎜⎝
⎞⎟⎠
ασy
ηyp σycr⋅+
⎡⎢⎣
⎤⎥⎦
1≤ "OK", "Need More Thickness",⎡⎢⎣
⎤⎥⎦
"OK"=
σx
ηxp σxcr⋅⎛⎜⎝
⎞⎟⎠
ασy
ηyp σycr⋅+
⎡⎢⎣
⎤⎥⎦
0.65= "OK, karena ratio nya < 1"
Propagation Buckling Check :
Ppr π1.15SMYSt
D t−⎛⎜⎝
⎞⎟⎠
2⋅:= * Ppr 38.219 psi=
Pe_max 36.089 psi= "OK, karena Ppr > Pe_max"
kPe_max
1.15πSMYS:= k 0.014=
Minimum Wall Thickness Due To Propagating Pressure
tnomk D⋅
1 k+:= tnom 0.437 in=
Collapse Pressure Check :
Cit
D⎛⎜⎝
⎞⎟⎠
32 E⋅
1 υ2
−
⎛⎜⎝
⎞⎟⎠
⋅:= * Ci 183.968 psi=
Constant of the quadratic equation are:
a 1:=
b 2SMYSt
D⋅ 1 0.03
D
t⋅+⎛⎜
⎝⎞⎟⎠Ci+⎡⎢
⎣⎤⎥⎦
−:= * b 2.039− 103
× psi=
c 2SMYSt
D⋅ Ci⋅:= * c 5.775 10
12×
lb2
ft2s4
⋅=
Det b2
4 a⋅ c⋅−:= Det 1.755 103
× psi=
x1b− Det+
2 a⋅:= x1 1.897 10
3× psi=
x2b− Det−
2a:= x2 141.823 psi=
Critical Collapse Pressure Is The Least Positif Root, Therefore
Pcr x1 x1 x2<if
x2 otherwise
:=Pcr 141.823 psi=
Pe_max 36.089 psi=
if Pcr Pe_max≤ "more thickness", "OK",( ) "OK"=
Safety Factor AgainstPressure Collapse SF
Pcr
Pe_max:=
SF 3.93= "OK, karena safety yangdidapatkan sangat besar"
"Digunakan wall thickness setebal 0.45 inch. Hal ini dikarenakan, saat memakai wallthickness sebesar 0.336 inch (hasil dari perhitungan akibat pressure containment),struktur pipa tidak kuat terhadap buckling."
FREE SPAN CALCULATIONDURING HYDROTEST PHASE
Equivalent ConditionPhase : HydrotestWave & Current Data : 1 year return period wave and current
pcflb
ft3
:=
INPUT DATA :
Pipeline Properties :
Outer Diameter
Wall Thickness
Corrosion Coating Thickness
Corrosion Coating Density
Concrete Coating Density
Content Density
Steel Density
Concrete Coating Thickness
Design Pressure
Structural Damping
Modulus Elasticity
SMYS
D 32in:=
t 0.45in:=
tcorr 0.125in:=
ρcorr 87.4pcf:=
ρcc 189.8pcf:=
ρcont 64pcf:=
ρst 490.1pcf:=
tcc 3in:=
Po 403.75psi:=
δ 0.126:=
E 3 107psi⋅:=
SMYS 52000psi:=
Environmental Parameter :
Hs 2.1m:=Significant Wave Height
Tp 11.01sec:=Spectral Peak Period
d 20m:=Water Depth
Ur 0.62ft sec1−
⋅:=Seabed Steady Current Velocity
Zr 2m:=
Seawater Density ρsw 64pcf:=
Kinematic Viscosity of Seawater ν 1.03 105−
⋅ ft2sec
1−⋅:=
Angle Between Wave Direction And Pipeline Direction φwave 90deg:=
Angle Between Current Direction And Pipeline Direction φcurr 90deg:=
CALCULATION :
Effective Weight :
This section calculates provided weight by pipeline properties section
Total Outside Diameter Dcc D 2tcorr+ 2tcc+:=
Dcc 38.25in=
Internal Diameter ID D 2t−:=
ID 31.1 in=
Corrosion Coating Diameter Dcorr D 2tcorr+:=
Dcorr 32.25in=
Steel Weight Wst 0.25π D2
ID2
−( )⋅ ρst⋅:=
Wst 151.804lb
ft=
Corrosion Coating Weight Wcorr 0.25π Dcorr2
D2
−( )⋅ ρcorr⋅:=
Wcorr 7.657lb
ft=
Concrete Coating Weight Wcc 0.25π Dcc2
Dcorr2
−( )⋅ ρcc⋅:=
Wcc 437.889lb
ft=
Content Weight Wcont 0.25π ID2
⋅ ρcont⋅:=
Wcont 337.62lb
ft=
Buoyancy B 0.25π Dcc2
⋅ ρsw⋅:=
B 510.705lb
ft=
Effective Weight Weff Wst Wcorr+ Wcc+ Wcont+ B+:=
Weff 1.446 103
×lb
ft=
External Pressure Pe ρsw g⋅ d⋅:=
Pe 29.163 psi=
Pressure Difference ΔP Po Pe−:=
ΔP 374.587 psi=
Elastic Modulus EI Eπ64
D4
ID4
−( )⋅⎡⎢⎣
⎤⎥⎦
⋅:=
EI 3.721 1010
×lb ft
3⋅
s2
=
Inertia Iπ64
D4
ID4
−( )⋅⎡⎢⎣
⎤⎥⎦
:=
I 0.268 ft4
=
Hydrodynamic Force Acting On Pipeline :
Minimum Required Submerged Weight Calculation According To DNV RP E305
Natural Period Parameter AccordingTo DNV RP E305 Figure 2.2 Tn
d
g:=
Tn 1.428 s=
Tn
Tp0.13= φ
Tp
Hs:= φ 7.598
s
m0.5
=
Peakness Parameter γ 5 φ 3.6s
m0.5
≤if
1 φ 5s
m0.5
≥if
3.3 otherwise
:=
γ 1=
Assuming There's No Reduction For Directional And Spreading Factor R = 1, Us* = Us
Wave Induced Current Velocity Perpendicular To The Pipe According To DNV RP E305Figure 2.1
Us0.01 Hs⋅
Tn:= Us 0.015
m
s=
Zero Up Crossing Period According To DNV RP E305 Figure 2.2
Tu 1.35 Tp⋅:= Tu 14.864 s=
From The Soil Parameter Data
Roughness Zo 5.21 106−
⋅ m:=
A1Dcc
Zo:= A1 1.865 10
5×=
B1Zo
Dcc:= B1 5.363 10
6−×=
Average Velocity To Reference Velocity Ratio
Ud1
lnZr
Zo1+⎛⎜
⎝⎞⎟⎠
1 B1+( ) ln A1 1+( )⋅ 1−⎡⎣ ⎤⎦⋅⎡⎢⎢⎣
⎤⎥⎥⎦
Ur⋅:=
Ud 0.164m
s=
Significant Acceleration As 2πUs
Tu:=
As 6.216 103−
×m
s2
=
Using Simplified Static Stability Method According To DNV RP E305
Current To Wave Velocity Ratio MUd
Us:= M 11.13=
Keulegan Carpenter Number KCUs Tu⋅Dcc
:= KC 0.225=
REUd Us+( ) Dcc⋅
ν:= RE 1.811 10
5×=
Hidrodynamic Force Coefficients
Drag Coefficient CD 1.2 RE 3 105−
⋅< M 0.8≥∧if
0.7 otherwise
:=
CD 0.7=
Lift Coefficient CL 0.9:=
Inertia Coefficient CM 3.29:=
Hydrodynamic Forces
Phase Angle Range i 0 90..:=
θi i deg⋅:=
Drag Force FD θ( ) 0.5ρswg
Dcc⋅ CD⋅ Us cos θ( )⋅ Ud+( ) 2⋅:=
Inertia Force FI θ( ) 0.25ρswg
π⋅ Dcc2
⋅ CM⋅ As⋅ sin θ( )⋅:=
Fw max FD θ( ) FI θ( )+( ):= Fw 1.711lb
ft= Fh Fw
2:=
0 20 40 60 80 1001
1.5
2
2.5
3
FD θ( ) FI θ( )+
θdeg
Dynamic Free Span :
Stability Number Ks2 Weff⋅ δ⋅
ρsw Dcc2
⋅:=
Ks 0.56=
Weff value can be changed depend on operation/installation phase (full/empty) + addedmass
In Line Analysis
Reduced Velocity According To DNV 1981 Graphic A.3 Vr 1.85:=
Note:
Con1 "In Line Oscillation":=
Con2 "Cross Flow Oscillation":=
Type of Oscillation Otype Con1 1 Vr< 3.5< Ks 1.8<∧if
Con2 otherwise
:=
Otype "In Line Oscillation"=
Strouhal Number According To DNV 1981 Graphic A.2 St 0.2:=
Vortex Shedding Frequency fvSt Ud Us+( )⋅
Dcc:=
fv 0.037Hz=
Condition At Both Ends of Span (Pinned To Pinned) C1 9.87:=
Critical Pipe Span Length LcrC1
2π
EI
Weff⋅ Dcc⋅
Vr
Us Ud+⋅:=
Lcr 86.372m=
Cross Flow Analysis
Reduced Velocity (Onset) According To DNV 1981 Graphic A.5 VrC1 4.9:=
LcrC1C1
2π
EI
Weff⋅ Dcc⋅
VrC1
Us Ud+⋅:=
LcrC1 140.568m=
Reduced Velocity (Peak) According To DNV 1981 Graphic A.5 VrC2 5.8:=
LcrC2C1
2π
EI
Weff⋅ Dcc⋅
VrC2
Us Ud+⋅:=
LcrC2 152.934m=
Static Free Span :
C2 8:=
Hoop Stress σhPo Pe− D⋅
2 t⋅:=
σh 1.332 104
× psi=
Yield Requirement
j 1 100..:= Lj j m⋅:=
Longitudinal Stress (End Cap Effect) σepσh2
:=
σep 6.659 103
× psi=
Total Longitudinal Stress
σx L( ) Weff B−( ) 2 Fh+⎡⎣
⎤⎦ L
2⋅ D⋅ g⋅
2 C2⋅ I⋅
⎡⎢⎣
⎤⎥⎦
σep+⎡⎢⎣
⎤⎥⎦
:=
0 20 40 60 80 1000
1 .105
2 .105
3 .105
4 .105
5 .105
σx L( )
psi
L
m
Allowable Stress (%)
Limiting Longitudinal Stress σxa L( ) 0.8SMYS:=
σxa L( ) 4.16 104
× psi=
Lcrit L( ) L 1m←
Lcrit L 1m−←
L L 1m+←
σx L 1m−( ) σxa L( )<while
Lcrit
:=
Lcrit L( ) 28m=
von Mises σe σx Lcrit L( )( ) 2 σh2
+:=
σe 4.289 104
× psi=
Limiting Equivalent Stress σxe L( ) 0.9SMYS:=
σxe L( ) 4.68 104
× psi=
if σe σxe L( )≤ "OK!", "Reduce The Length of Allowable Free Span",( ) "OK!"=
SUMMARY :
Critical Pipe Span Due To VIV In‐Line (Dynamic) Lcr 86.372m=
Critical Pipe Span Due To Cross‐Flow (Dynamic) LcrC1 140.568m=
Critical Pipe Span Due To Static Analysis Lcrit L( ) 28m=
FREE SPAN CALCULATIONDURING INSTALLATION PHASE
Equivalent ConditionPhase : InstallationWave & Current Data : 1 year return period wave and current
pcflb
ft3
:=
INPUT DATA :
Pipeline Properties :
Outer Diameter
Wall Thickness
Corrosion Coating Thickness
Corrosion Coating Density
Concrete Coating Density
Content Density
Steel Density
Concrete Coating Thickness
Design Pressure
Structural Damping
Modulus Elasticity
SMYS
D 32in:=
t 0.45in:=
tcorr 0.125in:=
ρcorr 87.4pcf:=
ρcc 189.8pcf:=
ρcont 0pcf:=
ρst 490.1pcf:=
tcc 3in:=
Po 0psi:=
δ 0.126:=
E 3 107psi⋅:=
SMYS 52000psi:=
Environmental Parameter :
Hs 2.1m:=Significant Wave Height
Tp 11.01sec:=Spectral Peak Period
d 20m:=Water Depth
Ur 0.62ft sec1−
⋅:=Seabed Steady Current Velocity
Zr 2m:=
Seawater Density ρsw 64pcf:=
Kinematic Viscosity of Seawater ν 1.03 105−
⋅ ft2sec
1−⋅:=
Angle Between Wave Direction And Pipeline Direction φwave 90deg:=
Angle Between Current Direction And Pipeline Direction φcurr 90deg:=
CALCULATION :
Effective Weight :
This section calculates provided weight by pipeline properties section
Total Outside Diameter Dcc D 2tcorr+ 2tcc+:=
Dcc 38.25in=
Internal Diameter ID D 2t−:=
ID 31.1 in=
Corrosion Coating Diameter Dcorr D 2tcorr+:=
Dcorr 32.25in=
Steel Weight Wst 0.25π D2
ID2
−( )⋅ ρst⋅:=
Wst 151.804lb
ft=
Corrosion Coating Weight Wcorr 0.25π Dcorr2
D2
−( )⋅ ρcorr⋅:=
Wcorr 7.657lb
ft=
Concrete Coating Weight Wcc 0.25π Dcc2
Dcorr2
−( )⋅ ρcc⋅:=
Wcc 437.889lb
ft=
Content Weight Wcont 0.25π ID2
⋅ ρcont⋅:=
Wcont 0=
Buoyancy B 0.25π Dcc2
⋅ ρsw⋅:=
B 510.705lb
ft=
Effective Weight Weff Wst Wcorr+ Wcc+ Wcont+ B+:=
Weff 1.108 103
×lb
ft=
External Pressure Pe ρsw g⋅ d⋅:=
Pe 29.163 psi=
Pressure Difference ΔP Po Pe−:=
ΔP 29.163 psi=
Elastic Modulus EI Eπ64
D4
ID4
−( )⋅⎡⎢⎣
⎤⎥⎦
⋅:=
EI 3.721 1010
×lb ft
3⋅
s2
=
Inertia Iπ64
D4
ID4
−( )⋅⎡⎢⎣
⎤⎥⎦
:=
I 0.268 ft4
=
Hydrodynamic Force Acting On Pipeline :
Minimum Required Submerged Weight Calculation According To DNV RP E305
Natural Period Parameter AccordingTo DNV RP E305 Figure 2.2 Tn
d
g:=
Tn 1.428 s=
Tn
Tp0.13= φ
Tp
Hs:= φ 7.598
s
m0.5
=
Peakness Parameter γ 5 φ 3.6s
m0.5
≤if
1 φ 5s
m0.5
≥if
3.3 otherwise
:=
γ 1=
Assuming There's No Reduction For Directional And Spreading Factor R = 1, Us* = Us
Wave Induced Current Velocity Perpendicular To The Pipe According To DNV RP E305Figure 2.1
Us0.01 Hs⋅
Tn:= Us 0.015
m
s=
Zero Up Crossing Period According To DNV RP E305 Figure 2.2
Tu 1.35 Tp⋅:= Tu 14.864 s=
From The Soil Parameter Data
Roughness Zo 5.21 106−
⋅ m:=
A1Dcc
Zo:= A1 1.865 10
5×=
B1Zo
Dcc:= B1 5.363 10
6−×=
Average Velocity To Reference Velocity Ratio
Ud1
lnZr
Zo1+⎛⎜
⎝⎞⎟⎠
1 B1+( ) ln A1 1+( )⋅ 1−⎡⎣ ⎤⎦⋅⎡⎢⎢⎣
⎤⎥⎥⎦
Ur⋅:=
Ud 0.164m
s=
Significant Acceleration As 2πUs
Tu:=
As 6.216 103−
×m
s2
=
Using Simplified Static Stability Method According To DNV RP E305
Current To Wave Velocity Ratio MUd
Us:= M 11.13=
Keulegan Carpenter Number KCUs Tu⋅Dcc
:= KC 0.225=
REUd Us+( ) Dcc⋅
ν:= RE 1.811 10
5×=
Hidrodynamic Force Coefficients
Drag Coefficient CD 1.2 RE 3 105−
⋅< M 0.8≥∧if
0.7 otherwise
:=
CD 0.7=
Lift Coefficient CL 0.9:=
Inertia Coefficient CM 3.29:=
Hydrodynamic Forces
Phase Angle Range i 0 90..:=
θi i deg⋅:=
Drag Force FD θ( ) 0.5ρswg
Dcc⋅ CD⋅ Us cos θ( )⋅ Ud+( ) 2⋅:=
Inertia Force FI θ( ) 0.25ρswg
π⋅ Dcc2
⋅ CM⋅ As⋅ sin θ( )⋅:=
Fw max FD θ( ) FI θ( )+( ):= Fw 1.711lb
ft= Fh Fw
2:=
0 20 40 60 80 1001
1.5
2
2.5
3
FD θ( ) FI θ( )+kg
m
θdeg
Dynamic Free Span :
Stability Number Ks2 Weff⋅ δ⋅
ρsw Dcc2
⋅:=
Ks 0.429=
Weff value can be changed depend on operation/installation phase (full/empty) + addedmass
In Line Analysis
Reduced Velocity According To DNV 1981 Graphic A.3 Vr 1.7:=
Note:
Con1 "In Line Oscillation":=
Con2 "Cross Flow Oscillation":=
Type of Oscillation Otype Con1 1 Vr< 3.5< Ks 1.8<∧if
Con2 otherwise
:=
Otype "In Line Oscillation"=
Strouhal Number According To DNV 1981 Graphic A.2 St 0.2:=
Vortex Shedding Frequency fvSt Ud Us+( )⋅
Dcc:=
fv 0.037Hz=
Condition At Both Ends of Span (Pinned To Pinned) C1 9.87:=
Critical Pipe Span Length LcrC1
2π
EI
Weff⋅ Dcc⋅
Vr
Us Ud+⋅:=
Lcr 88.489m=
Cross Flow Analysis
Reduced Velocity (Onset) According To DNV 1981 Graphic A.5 VrC1 4.9:=
LcrC1C1
2π
EI
Weff⋅ Dcc⋅
VrC1
Us Ud+⋅:=
LcrC1 150.233m=
Reduced Velocity (Peak) According To DNV 1981 Graphic A.5 VrC2 5.8:=
LcrC2C1
2π
EI
Weff⋅ Dcc⋅
VrC2
Us Ud+⋅:=
LcrC2 163.448m=
Static Free Span :
C2 8:=
Hoop Stress σhPo Pe− D⋅
2 t⋅:=
σh 1.037 103
× psi=
Yield Requirement
j 1 100..:= Lj j m⋅:=
Longitudinal Stress (End Cap Effect) σepσh2
:=
σep 518.454 psi=
Total Longitudinal Stress
σx L( ) Weff B−( ) 2 Fh+⎡⎣
⎤⎦ L
2⋅ D⋅ g⋅
2 C2⋅ I⋅
⎡⎢⎣
⎤⎥⎦
σep+⎡⎢⎣
⎤⎥⎦
:=
0 20 40 60 80 1000
5.5 .104
1.1 .105
1.65 .105
2.2 .105
2.75 .105
σx L( )
psi
L
m
Allowable Stress (%)
Limiting Longitudinal Stress σxa L( ) 0.8SMYS:=
σxa L( ) 4.16 104
× psi=
Lcrit L( ) L 1m←
Lcrit L 1m−←
L L 1m+←
σx L 1m−( ) σxa L( )<while
Lcrit
:=
Lcrit L( ) 38m=
von Mises σe σx Lcrit L( )( ) 2 σh2
+:=
σe 4.068 104
× psi=
Limiting Equivalent Stress σxe L( ) 0.9SMYS:=
σxe L( ) 4.68 104
× psi=
if σe σxe L( )≤ "OK!", "Reduce The Length of Allowable Free Span",( ) "OK!"=
SUMMARY :
Critical Pipe Span Due To VIV In‐Line (Dynamic) Lcr 88.489m=
Critical Pipe Span Due To Cross‐Flow (Dynamic) LcrC1 150.233m=
Critical Pipe Span Due To Static Analysis Lcrit L( ) 38m=
FREE SPAN CALCULATIONDURING OPERATION PHASE
Equivalent ConditionPhase : OperationWave & Current Data : 100 year return period wave and current
pcflb
ft3
:=
INPUT DATA :
Pipeline Properties :
Outer Diameter
Wall Thickness
Corrosion Coating Thickness
Corrosion Coating Density
Concrete Coating Density
Content Density
Steel Density
Concrete Coating Thickness
Design Pressure
Structural Damping
Modulus Elasticity
SMYS
D 32in:=
t 0.45in:=
tcorr 0.125in:=
ρcorr 87.4pcf:=
ρcc 189.8pcf:=
ρcont 54pcf:=
ρst 490.1pcf:=
tcc 3in:=
Po 323psi:=
δ 0.126:=
E 3 107psi⋅:=
SMYS 52000psi:=
Environmental Parameter :
Hs 11.2m:=Significant Wave Height
Tp 15.2sec:=Spectral Peak Period
d 20m:=Water Depth
Ur 1.27ft sec1−
⋅:=Seabed Steady Current Velocity
Zr 2m:=
Seawater Density ρsw 64pcf:=
Kinematic Viscosity of Seawater ν 1.03 105−
⋅ ft2sec
1−⋅:=
Angle Between Wave Direction And Pipeline Direction φwave 90deg:=
Angle Between Current Direction And Pipeline Direction φcurr 90deg:=
CALCULATION :
Effective Weight :
This section calculates provided weight by pipeline properties section
Total Outside Diameter Dcc D 2tcorr+ 2tcc+:=
Dcc 38.25in=
Internal Diameter ID D 2t−:=
ID 31.1 in=
Corrosion Coating Diameter Dcorr D 2tcorr+:=
Dcorr 32.25in=
Steel Weight Wst 0.25π D2
ID2
−( )⋅ ρst⋅:=
Wst 151.804lb
ft=
Corrosion Coating Weight Wcorr 0.25π Dcorr2
D2
−( )⋅ ρcorr⋅:=
Wcorr 7.657lb
ft=
Concrete Coating Weight Wcc 0.25π Dcc2
Dcorr2
−( )⋅ ρcc⋅:=
Wcc 437.889lb
ft=
Content Weight Wcont 0.25π ID2
⋅ ρcont⋅:=
Wcont 284.867lb
ft=
Buoyancy B 0.25π Dcc2
⋅ ρsw⋅:=
B 510.705lb
ft=
Effective Weight Weff Wst Wcorr+ Wcc+ Wcont+ B+:=
Weff 1.393 103
×lb
ft=
External Pressure Pe ρsw g⋅ d⋅:=
Pe 29.163 psi=
Pressure Difference ΔP Po Pe−:=
ΔP 293.837 psi=
Elastic Modulus EI Eπ64
D4
ID4
−( )⋅⎡⎢⎣
⎤⎥⎦
⋅:=
EI 3.721 1010
×lb ft
3⋅
s2
=
Inertia Iπ64
D4
ID4
−( )⋅⎡⎢⎣
⎤⎥⎦
:=
I 0.268 ft4
=Hydrodynamic Force Acting On Pipeline :
Minimum Required Submerged Weight Calculation According To DNV RP E305
Natural Period Parameter AccordingTo DNV RP E305 Figure 2.2 Tn
d
g:=
Tn 1.428 s=
Tn
Tp0.094= φ
Tp
Hs:= φ 4.542
s
m0.5
=
Peakness Parameter γ 5 φ 3.6s
m0.5
≤if
1 φ 5s
m0.5
≥if
3.3 otherwise
:=
γ 3.3=
Assuming There's No Reduction For Directional And Spreading Factor R = 1, Us* = Us
Wave Induced Current Velocity Perpendicular To The Pipe According To DNV RP E305Figure 2.1
Us0.02 Hs⋅
Tn:= Us 0.157
m
s=
Zero Up Crossing Period According To DNV RP E305 Figure 2.2
Tu 1.25 Tp⋅:= Tu 19 s=
From The Soil Parameter Data
Roughness Zo 5.21 106−
⋅ m:=
A1Dcc
Zo:= A1 1.865 10
5×=
B1Zo
Dcc:= B1 5.363 10
6−×=
Average Velocity To Reference Velocity Ratio
Ud1
lnZr
Zo1+⎛⎜
⎝⎞⎟⎠
1 B1+( ) ln A1 1+( )⋅ 1−⎡⎣ ⎤⎦⋅⎡⎢⎢⎣
⎤⎥⎥⎦
Ur⋅:=
Ud 0.335m
s=
Significant Acceleration As 2πUs
Tu:=
As 0.052m
s2
=
Using Simplified Static Stability Method According To DNV RP E305
Current To Wave Velocity Ratio MUd
Us:= M 2.137=
Keulegan Carpenter Number KCUs Tu⋅Dcc
:= KC 3.067=
REUd Us+( ) Dcc⋅
ν:= RE 4.996 10
5×=
Hidrodynamic Force Coefficients
Drag Coefficient CD 1.2 RE 3 105−
⋅< M 0.8≥∧if
0.7 otherwise
:=
CD 0.7=
Lift Coefficient CL 0.9:=
Inertia Coefficient CM 3.29:=
Hydrodynamic Forces
Phase Angle Range i 0 90..:=
θi i deg⋅:=
Drag Force FD θ( ) 0.5ρswg
Dcc⋅ CD⋅ Us cos θ( )⋅ Ud+( ) 2⋅:=
Inertia Force FI θ( ) 0.25ρswg
π⋅ Dcc2
⋅ CM⋅ As⋅ sin θ( )⋅:=
Fw max FD θ( ) FI θ( )+( ):= Fw 11.97lb
ft= Fh Fw
2:=
0 20 40 60 80 1005
10
15
20
FD θ( ) FI θ( )+
θdeg
Dynamic Free Span :
Stability Number Ks2 Weff⋅ δ⋅
ρsw Dcc2
⋅:=
Ks 0.54=
Weff value can be changed depend on operation/installation phase (full/empty) + addedmass
In Line Analysis
Reduced Velocity According To DNV 1981 Graphic A.3 Vr 1.7:=
Note:
Con1 "In Line Oscillation":=
Con2 "Cross Flow Oscillation":=
Type of Oscillation Otype Con1 1 Vr< 3.5< Ks 1.8<∧if
Con2 otherwise
:=
Otype "In Line Oscillation"=
Strouhal Number According To DNV 1981 Graphic A.2 St 0.225:=
Vortex Shedding Frequency fvSt Ud Us+( )⋅
Dcc:=
fv 0.114Hz=
Condition At Both Ends of Span (Pinned To Pinned) C1 9.87:=
Critical Pipe Span Length LcrC1
2π
EI
Weff⋅ Dcc⋅
Vr
Us Ud+⋅:=
Lcr 50.313m=
Cross Flow Analysis
Reduced Velocity (Onset) According To DNV 1981 Graphic A.5 VrC1 4.7:=
LcrC1C1
2π
EI
Weff⋅ Dcc⋅
VrC1
Us Ud+⋅:=
LcrC1 83.658m=
Reduced Velocity (Peak) According To DNV 1981 Graphic A.5 VrC2 5.75:=
LcrC2C1
2π
EI
Weff⋅ Dcc⋅
VrC2
Us Ud+⋅:=
LcrC2 92.532m=
Static Free Span :
C2 8:=
Hoop Stress σhPo Pe− D⋅
2 t⋅:=
σh 1.045 104
× psi=
Yield Requirement
j 1 100..:= Lj j m⋅:=
Longitudinal Stress (End Cap Effect) σepσh2
:=
σep 5.224 103
× psi=
Total Longitudinal Stress
σx L( ) Weff B−( ) 2 Fh+⎡⎣
⎤⎦ L
2⋅ D⋅ g⋅
2 C2⋅ I⋅
⎡⎢⎣
⎤⎥⎦
σep+⎡⎢⎣
⎤⎥⎦
:=
0 20 40 60 80 1000
1 .109
2 .109
3 .109
σx L( )
L
m
Allowable Stress (%)
Limiting Longitudinal Stress σxa L( ) 0.8SMYS:=
σxa L( ) 4.16 104
× psi=
Lcrit L( ) L 1m←
Lcrit L 1m−←
L L 1m+←
σx L 1m−( ) σxa L( )<while
Lcrit
:=
Lcrit L( ) 29m=
von Mises σe σx Lcrit L( )( ) 2 σh2
+:=
σe 4.111 104
× psi=
Limiting Equivalent Stress σxe L( ) 0.9SMYS:=
σxe L( ) 4.68 104
× psi=
if σe σxe L( )≤ "OK!", "Reduce The Length of Allowable Free Span",( ) "OK!"=
SUMMARY :
Critical Pipe Span Due To VIV In‐Line (Dynamic) Lcr 50.313m=
Critical Pipe Span Due To Cross‐Flow (Dynamic) LcrC1 83.658m=
Critical Pipe Span Due To Static Analysis Lcrit L( ) 29m=
ON-BOTTOM STABILITY CALCULATIONDURING INSTALLATION PHASE
Equivalent ConditionPhase : InstallationWave & Current Data : 1 year return period wave and current
pcflb
ft3
:=
INPUT DATA :
Pipeline Properties :
Outer Diameter
Wall Thickness
Corrosion Coating Thickness
Corrosion Coating Density
Concrete Coating Density
Content Density
Steel Density
Concrete Coating Thickness
D 32in:=
t 0.45in:=
tcorr 0.125in:=
ρcorr 87.4pcf:=
ρcc 189.8pcf:=
ρcont 0pcf:=
ρst 490.1pcf:=
tcc 3in:=
Environmental Parameter :Hs 2.2m:=Significant Wave HeightTp 11.01sec:=Spectral Peak Periodd 20m:=Water DepthUr 0.62ft sec
1−⋅:=Seabed Steady Current Velocity
Zr 2m:=
Seawater Density ρsw 64pcf:=
Kinematic Viscosity of Seawater ν 1.03 10 5−⋅ ft
2sec
1−⋅:=
Angle Between Wave Direction And Pipeline Direction φwave 90deg:=
Angle Between Current Direction And Pipeline Direction φcurr 90deg:=
CALCULATIONS :
Submerged Weight :
This section calculates provided weight by pipeline properties section
Total Outside Diameter Dcc D 2tcorr+ 2tcc+:=
Dcc 38.25 in=
Internal Diameter ID D 2t−:=
ID 31.1 in=
Corrosion Coating Diameter Dcorr D 2tcorr+:=
Dcorr 32.25 in=
Steel Weight Wst 0.25π D2
ID2
−( )⋅ ρst⋅:=
Wst 225.91kg
m=
Corrosion Coating Weight Wcorr 0.25π Dcorr2
D2
−( )⋅ ρcorr⋅:=
Wcorr 11.395kg
m=
Concrete Coating Weight Wcc 0.25π Dcc2
Dcorr2
−( )⋅ ρcc⋅:=
Wcc 651.651kg
m=
Content Weight Wcont 0.25π ID2
⋅ ρcont⋅:=
Wcont 0=
Buoyancy B 0.25π Dcc2
⋅ ρsw⋅:=
B 760.013kg
m=
Submerged Weight Wsub Wst Wcorr+ Wcc+ Wcont+ B−:=
Wsub 128.942kg
m=
Vertical Stability :
Specific Gravity VSWsub B+
B:= VS 1.1≥
VS 1.17=
if VS 1.1< "Need More Thickness", "OK!",( ) "OK!"=
Hydrodynamic Force Acting On Pipeline :
Minimum Required Submerged Weight Calculation According To DNV RP E305
Natural Period Parameter AccordingTo DNV RP E305 Figure 2.2 Tn
d
g:=
Tn 1.428 s=
Tn
Tp0.13= φ
Tp
Hs:= φ 7.423
s
m0.5
=
Peakness Parameter γ 5 φ 3.6s
m0.5
≤if
1 φ 5s
m0.5
≥if
3.3 otherwise
:=
γ 1=
Assuming There's No Reduction For Directional And Spreading Factor R = 1, Us* = Us
Wave Induced Current Velocity Perpendicular To The Pipe According To DNV RP E305 Figure 2.1
Us0.01 Hs⋅
Tn:= Us 0.015
m
s=
Zero Up Crossing Period According To DNV RP E305 Figure 2.2
Tu 1.35 Tp⋅:= Tu 14.864 s=
From The Soil Parameter Data
Roughness Zo 5.21 10 6−⋅ m:=
A1Dcc
Zo:= A1 1.865 105
×=
B1Zo
Dcc:= B1 5.363 10 6−
×=
Average Velocity To Reference Velocity Ratio
Ud1
lnZr
Zo1+⎛⎜
⎝⎞⎟⎠
1 B1+( ) ln A1 1+( )⋅ 1−⎡⎣ ⎤⎦⋅⎡⎢⎢⎣
⎤⎥⎥⎦
Ur⋅:=
Ud 0.164m
s=
Significant Acceleration As 2πUs
Tu:=
As 6.512 10 3−×
m
s2
=
Using Simplified Static Stability Method According To DNV RP E305
Current To Wave Velocity Ratio MUd
Us:= M 10.624=
Keulegan Carpenter Number KCUs Tu⋅
Dcc:= KC 0.236=
REUd Us+( ) Dcc⋅
ν:= RE 1.818 105
×=
Hidrodynamic Force Coefficients
Drag Coefficient CD 1.2 RE 3 10 5−⋅< M 0.8≥∧if
0.7 otherwise
:=
CD 0.7=
Lift Coefficient CL 0.9:=
Inertia Coefficient CM 3.29:=
Soil Friction Coefficient
Soil Type: Sand
μ 0.7:=
Calibration Factor According To DNV RP E305 Figure 5.12
M 10.624=
KC 0.236=
Fw 1:=
Hydrodynamic Forces vs Required Submerged Weight :
Phase Angle Range i 0 90..:=
θ i i deg⋅:=
Lift Force FL θ( ) 0.5ρsw
gDcc⋅ CL⋅ Us cos θ( )⋅ Ud+( )2⋅:=
Drag Force FD θ( ) 0.5ρsw
gDcc⋅ CD⋅ Us cos θ( )⋅ Ud+( )2⋅:=
Inertia Force FI θ( ) 0.25ρsw
gπ⋅ Dcc
2⋅ CM⋅ As⋅ sin θ( )⋅:=
Required Submerged Weight Ws θ( ) FwFD θ( ) FI θ( )+ μ FL θ( )⋅+
μ⎛⎜⎝
⎞⎟⎠
⋅:=
0 20 40 60 80 1002
2.5
3
3.5
Ws θ( )lb
ft
θdeg
Wreq max Ws θ( )( ):=
Wreq 5.007kg
m= Wsub 128.942
kg
m=
if Wsub Wreq≤ "Need More Thickness", "OK!",( ) "OK!"=
Safety Factor For Submerged Weight Due To Requirement Weight
SFwWsub
Wreq:= SFw 25.752=
ON-BOTTOM STABILITY CALCULATIONDURING OPERATION CORRODED PHASE
Equivalent ConditionPhase : Operation CorrodedWave & Current Data : 100 year return period wave and current
pcflb
ft3
:=
INPUT DATA :
Pipeline Properties :
Outer Diameter
Wall Thickness
Corrosion Coating Thickness
Corrosion Coating Density
Concrete Coating Density
Content Density
Steel Density
Concrete Coating Thickness
Corrosion Allowance
D 32in:=
t 0.45in:=
tcorr 0.125in:=
ρcorr 87.4pcf:=
ρcc 189.8pcf:=
ρcont 54pcf:=
ρst 490.1pcf:=
tcc 3in:=
ca 0.125in:=
CA 0.7 ca⋅:=
Environmental Parameter :Hs 11.2m:=Significant Wave HeightTp 15.2sec:=Spectral Peak Periodd 20m:=Water Depth
Seabed Steady Current Velocity Ur 1.27ft sec1−
⋅:=
Zr 2m:=
Seawater Density ρsw 64pcf:=
Kinematic Viscosity of Seawater ν 1.03 10 5−⋅ ft
2sec
1−⋅:=
Angle Between Wave Direction And Pipeline Direction φwave 90deg:=
Angle Between Current Direction And Pipeline Direction φcurr 90deg:=
CALCULATION :
Submerged Weight :
This section calculates provided weight by pipeline properties section
Total Outside Diameter Dcc D 2tcorr+ 2tcc+:=Dcc 38.25 in=
Internal Diameter ID D 2t− 2 CA⋅+:=ID 31.275 in=
Corrosion Coating Diameter Dcorr D 2tcorr+:=Dcorr 32.25 in=
Steel Weight Wst 0.25π D2
ID2
−( )⋅ ρst⋅:=
Wst 182.487kg
m=
Corrosion Coating Weight Wcorr 0.25π Dcorr2
D2
−( )⋅ ρcorr⋅:=
Wcorr 11.395kg
m=
Concrete Coating Weight Wcc 0.25π Dcc2
Dcorr2
−( )⋅ ρcc⋅:=
Wcc 651.651kg
m=
Content Weight Wcont 0.25π ID2
⋅ ρcont⋅:=
Wcont 428.713kg
m=
Buoyancy B 0.25π Dcc2
⋅ ρsw⋅:=
B 760.013kg
m=
Submerged Weight Wsub Wst Wcorr+ Wcc+ Wcont+ B−:=
Wsub 514.233kg
m=
Vertical Stability :
Specific Gravity VSWsub B+
B:= VS 1.1≥
VS 1.677=
if VS 1.1< "Need More Thickness", "OK!",( ) "OK!"=
Hydrodynamic Force Acting On Pipeline :
Minimum Required Submerged Weight Calculation According To DNV RP E305
Natural Period Parameter AccordingTo DNV RP E305 Figure 2.2 Tn
d
g:=
Tn 1.428 s=
Tn
Tp0.094= φ
Tp
Hs:= φ 4.542
s
m0.5
=
Peakness Parameter γ 5 φ 3.6s
m0.5
≤if
1 φ 5s
m0.5
≥if
3.3 otherwise
:=
γ 3.3=
Assuming There's No Reduction For Directional And Spreading Factor R = 1, Us* = Us
Wave Induced Current Velocity Perpendicular To The Pipe According To DNV RP E305 Figure 2.1
Us0.02 Hs⋅
Tn:= Us 0.157
m
s=
Zero Up Crossing Period According To DNV RP E305 Figure 2.2
Tu 1.25 Tp⋅:= Tu 19 s=
From The Soil Parameter Data
Roughness Zo 5.21 10 6−⋅ m:=
A1Dcc
Zo:= A1 1.865 105
×=
B1Zo
Dcc:= B1 5.363 10 6−
×=
Average Velocity To Reference Velocity Ratio
Ud1
lnZr
Zo1+⎛⎜
⎝⎞⎟⎠
1 B1+( ) ln A1 1+( )⋅ 1−⎡⎣ ⎤⎦⋅⎡⎢⎢⎣
⎤⎥⎥⎦
Ur⋅:=
Ud 0.335m
s=
Significant Acceleration As 2πUs
Tu:=
As 0.052m
s2
=
Using Simplified Static Stability Method According To DNV RP E305
Current To Wave Velocity Ratio MUd
Us:= M 2.137=
Keulegan Carpenter Number KCUs Tu⋅
Dcc:= KC 3.067=
REUd Us+( ) Dcc⋅
ν:= RE 4.996 105
×=
Hidrodynamic Force Coefficients
Drag Coefficient CD 1.2 RE 3 10 5−⋅< M 0.8≥∧if
0.7 otherwise
:=
CD 0.7=
Lift Coefficient CL 0.9:=
Inertia Coefficient CM 3.29:=
Soil Friction Coefficient According To Soil Properties Data
Soil Type: Sand
μ 0.7:=
Calibration Factor According To DNV RP E305 Figure 5.12
M 2.137=
KC 3.067=
Fw 1:=
Hydrodynamic Forces And Required Submerged Weight
Phase Angle Range i 0 90..:=
θ i i deg⋅:=
Lift Force FL θ( ) 0.5ρsw
gDcc⋅ CL⋅ Us cos θ( )⋅ Ud+( )2⋅:=
Drag Force FD θ( ) 0.5ρsw
gDcc⋅ CD⋅ Us cos θ( )⋅ Ud+( )2⋅:=
Inertia Force FI θ( ) 0.25ρsw
gπ⋅ Dcc
2⋅ CM⋅ As⋅ sin θ( )⋅:=
Required Submerged Weight Ws θ( ) FwFD θ( ) FI θ( )+ μ FL θ( )⋅+
μ⎛⎜⎝
⎞⎟⎠
⋅:=
Plot Submerged Weight vs Phase Angle
0 20 40 60 80 10014
16
18
20
22
24
Ws θ( )lb
ft
θdeg
Wreq max Ws θ( )( ):=
Wreq 32.925kg
m= Wsub 514.233
kg
m=
if Wsub Wreq≤ "Need More Thickness", "OK!",( ) "OK!"=
Safety Factor For Submerged Weight Due To Requirement Weight
SFwWsub
Wreq:= SFw 15.618=
ON-BOTTOM STABILITY CALCULATIONDURING OPERATION PHASE
Equivalent ConditionPhase : OperationWave & Current Data : 100 year return period wave and current
pcflb
ft3
:=
INPUT DATA :
Pipeline Properties :
Outer Diameter
Wall Thickness
Corrosion Coating Thickness
Corrosion Coating Density
Concrete Coating Density
Content Density
Steel Density
Concrete Coating Thickness
D 32in:=
t 0.45in:=
tcorr 0.125in:=
ρcorr 87.4pcf:=
ρcc 189.8pcf:=
ρcont 54pcf:=
ρst 490.1pcf:=
tcc 3in:=
Environmental Parameter :Hs 11.2m:=Significant Wave HeightTp 15.2sec:=Spectral Peak Periodd 20m:=Water DepthUr 1.27ft sec
1−⋅:=Seabed Steady Current Velocity
Zr 2m:=
Seawater Density ρsw 64pcf:=
Kinematic Viscosity of Seawater ν 1.03 10 5−⋅ ft
2sec
1−⋅:=
Angle Between Wave Direction And Pipeline Direction φwave 90deg:=
Angle Between Current Direction And Pipeline Direction φcurr 90deg:=
CALCULATIONS :
Submerged Weight :
This section calculates provided weight by pipeline properties section
Total Outside Diameter Dcc D 2tcorr+ 2tcc+:=
Dcc 38.25 in=
Internal Diameter ID D 2t−:=
ID 31.1 in=
Corrosion Coating Diameter Dcorr D 2tcorr+:=
Dcorr 32.25 in=
Steel Weight Wst 0.25π D2
ID2
−( )⋅ ρst⋅:=
Wst 225.91kg
m=
Corrosion Coating Weight Wcorr 0.25π Dcorr2
D2
−( )⋅ ρcorr⋅:=
Wcorr 11.395kg
m=
Concrete Coating Weight Wcc 0.25π Dcc2
Dcorr2
−( )⋅ ρcc⋅:=
Wcc 651.651kg
m=
Content Weight Wcont 0.25π ID2
⋅ ρcont⋅:=
Wcont 423.929kg
m=
Buoyancy B 0.25π Dcc2
⋅ ρsw⋅:=
B 760.013kg
m=
Submerged Weight Wsub Wst Wcorr+ Wcc+ Wcont+ B−:=
Wsub 552.87kg
m=
Vertical Stability :
Specific Gravity VSWsub B+
B:= VS 1.1≥
VS 1.727=
if VS 1.1< "Need More Thickness", "OK!",( ) "OK!"=
Hydrodynamic Force Acting On Pipeline :
Minimum Required Submerged Weight Calculation According To DNV RP E305
Natural Period Parameter AccordingTo DNV RP E305 Figure 2.2 Tn
d
g:=
Tn 1.428 s=
Tn
Tp0.094= φ
Tp
Hs:= φ 4.542
s
m0.5
=
Peakness Parameter γ 5 φ 3.6s
m0.5
≤if
1 φ 5s
m0.5
≥if
3.3 otherwise
:=
γ 3.3=
Assuming There's No Reduction For Directional And Spreading Factor R = 1, Us* = Us
Wave Induced Current Velocity Perpendicular To The Pipe According To DNV RP E305 Figure 2.1
Us0.01 Hs⋅
Tn:= Us 0.078
m
s=
Zero Up Crossing Period According To DNV RP E305 Figure 2.2
Tu 1.35 Tp⋅:= Tu 20.52 s=
From The Soil Parameter Data
Roughness Zo 5.21 10 6−⋅ m:=
A1Dcc
Zo:= A1 1.865 105
×=
B1Zo
Dcc:= B1 5.363 10 6−
×=
Average Velocity To Reference Velocity Ratio
Ud1
lnZr
Zo1+⎛⎜
⎝⎞⎟⎠
1 B1+( ) ln A1 1+( )⋅ 1−⎡⎣ ⎤⎦⋅⎡⎢⎢⎣
⎤⎥⎥⎦
Ur⋅:=
Ud 0.335m
s=
Significant Acceleration As 2πUs
Tu:=
As 0.024m
s2
=
Using Simplified Static Stability Method According To DNV RP E305
Current To Wave Velocity Ratio MUd
Us:= M 4.275=
Keulegan Carpenter Number KCUs Tu⋅
Dcc:= KC 1.656=
REUd Us+( ) Dcc⋅
ν:= RE 4.2 105
×=
Hidrodynamic Force Coefficients
Drag Coefficient CD 1.2 RE 3 10 5−⋅< M 0.8≥∧if
0.7 otherwise
:=
CD 0.7=
Lift Coefficient CL 0.9:=
Inertia Coefficient CM 3.29:=
Soil Friction Coefficient
Soil Type: Sand
μ 0.7:=
Calibration Factor According To DNV RP E305 Figure 5.12
M 4.275=
KC 1.656=
Fw 1:=
Hydrodynamic Forces vs Required Submerged Weight :
Phase Angle Range i 0 90..:=
θ i i deg⋅:=
Lift Force FL θ( ) 0.5ρsw
gDcc⋅ CL⋅ Us cos θ( )⋅ Ud+( )2⋅:=
Drag Force FD θ( ) 0.5ρsw
gDcc⋅ CD⋅ Us cos θ( )⋅ Ud+( )2⋅:=
Inertia Force FI θ( ) 0.25ρsw
gπ⋅ Dcc
2⋅ CM⋅ As⋅ sin θ( )⋅:=
Required Submerged Weight Ws θ( ) FwFD θ( ) FI θ( )+ μ FL θ( )⋅+
μ⎛⎜⎝
⎞⎟⎠
⋅:=
0 20 40 60 80 10011
12
13
14
15
Ws θ( )lb
ft
θdeg
Wreq max Ws θ( )( ):=
Wreq 21.12kg
m= Wsub 552.87
kg
m=
if Wsub Wreq≤ "Need More Thickness", "OK!",( ) "OK!"=
Safety Factor For Submerged Weight Due To Requirement Weight
SFwWsub
Wreq:= SFw 26.177=
WALL THICKNESS CALCULATIONDURING HYDROTEST CONDITION
DATA INPUT:
Nominal Water Depth (MSL) dnom 65.6ft:=
Highest Astronomical Tide HAT 12.5ft:=
Storm Surge (1 year) SS 0ft:=
Maximum Wave Height Hmax 6.2ft:=
Maximum Water Depth dmax dnom HAT+ SS+Hmax
2+:=
dmax 81.2 ft=
Minimum Water Depth dmin 0ft:=
Usage Factor (according to DNV 81Section 4 Table 4.1)
ηh_1 0.72:=
ηh_2 0.5:=
Gravity g 32.174ft
s2
=
Temperatur Derating Faktor kt 1:=
Seawater Density ρsw 64lb
ft3
:=
Maximum External Pressure Pe_max ρsw g⋅ dmax⋅:=
Pe_max 36.089 psi=
Minimum External Presure Pe_min ρsw g⋅ dmin⋅:=
Pe_min 0=
Pressure Design (hidrotes) Pd 403.75psi:=
Outside Diameter D 32in:=
Corrosion Allowance CA 0.125in:=
Tsweet 0.7 CA⋅:=
Material API 5L X‐52
Spesified Minimum Yield Stress SMYS 52000psi:=
Modulus Elasticity E 3.01 107
× psi:=
CALCULATIONS:
1. Standard DNV 81
Zone 1
Minimum Req. Wall Thickness tDNV_1Pd Pe_min−( ) D⋅
2 ηh_1⋅ SMYS⋅ kt⋅:=
tDNV_1 0.173 in=
Nominal Wall Thickness tnom_1_DNV_sw tDNV_1 Tsweet+:=
tnom_1_DNV_sw 0.26 in=
Zone 2tDNV_2
Pd Pe_min−( ) D⋅
2 ηh_2⋅ SMYS⋅ kt⋅:=Minimum Req. Wall Thickness
tDNV_2 0.248 in=
Nominal Wall Thickness tnom_2_DNV_sw tDNV_2 Tsweet+:=
tnom_2_DNV_sw 0.336 in=
2. STANDARD ASME B31.8
Longitudinal Joint Factor E1 1:=
S1 0.72 E1⋅ SMYS⋅:= S1 3.744 104
× psi=
Design Hoop Stress
Minimum Wall Thickness tASMEPd D⋅
2 S1⋅:= tASME 0.173 in=
Nominal Wall Thickness tnom_ASME_sw tASME Tsweet+:=
tnom_ASME_sw 0.26 in=
SUMMARY AND CONCLUSION:
DNV 81
Zone 1 tnom_1_DNV_sw 0.26 in=
Zone 2 tnom_2_DNV_sw 0.336 in=
ASME B31.8
tnom_ASME_sw 0.26 in=
WALL THICKNESS CALCULATIONDURING INSTALLATION CONDITION
DATA INPUT:
Nominal Water Depth (MSL) dnom 65.6ft:=
Highest Astronomical Tide HAT 12.5ft:=
Storm Surge (1 year) SS 0ft:=
Maximum Wave Height Hmax 6.2ft:=
Maximum Water Depth dmax dnom HAT+ SS+Hmax
2+:=
dmax 81.2 ft=
Minimum Water Depth dmin 0ft:=
Usage Factor (according to DNV 81Section 4 Table 4.1)
ηh_1 0.72:=
ηh_2 0.5:=
Gravity g 32.174ft
s2
=
Temperatur Derating Faktor kt 1:=
Seawater Density ρsw 64lb
ft3
:=
Maximum External Pressure Pe_max ρsw g⋅ dmax⋅:=
Pe_max 36.089 psi=
Minimum External Presure Pe_min ρsw g⋅ dmin⋅:=
Pe_min 0=
Pressure Design (hidrotes) Pd 323psi:=
Outside Diameter D 32in:=
Corrosion Allowance CA 0.125in:=
Tsweet 0.7 CA⋅:=
Material API 5L X‐52
Spesified Minimum Yield Stress SMYS 52000psi:=
Modulus Elasticity E 3.01 107
× psi:=
CALCULATIONS:
1. Standard DNV 81
Zone 1
Minimum Req. Wall Thickness tDNV_1Pd Pe_min−( ) D⋅
2 ηh_1⋅ SMYS⋅ kt⋅:=
tDNV_1 0.138 in=
Nominal Wall Thickness tnom_1_DNV_sw tDNV_1 Tsweet+:=
tnom_1_DNV_sw 0.226 in=
Zone 2tDNV_2
Pd Pe_min−( ) D⋅
2 ηh_2⋅ SMYS⋅ kt⋅:=Minimum Req. Wall Thickness
tDNV_2 0.199 in=
Nominal Wall Thickness tnom_2_DNV_sw tDNV_2 Tsweet+:=
tnom_2_DNV_sw 0.286 in=
2. STANDARD ASME B31.8
Longitudinal Joint Factor E1 1:=
S1 0.72 E1⋅ SMYS⋅:= S1 3.744 104
× psi=
Design Hoop Stress
Minimum Wall Thickness tASMEPd D⋅
2 S1⋅:= tASME 0.138 in=
Nominal Wall Thickness tnom_ASME_sw tASME Tsweet+:=
tnom_ASME_sw 0.226 in=
SUMMARY AND CONCLUSION:
DNV 81
Zone 1 tnom_1_DNV_sw 0.226 in=
Zone 2 tnom_2_DNV_sw 0.286 in=
ASME B31.8
tnom_ASME_sw 0.226 in=
WALL THICKNESS CALCULATIONDURING OPERATION CONDITION
DATA INPUT:
Nominal Water Depth (MSL) dnom 65.6ft:=
Highest Astronomical Tide HAT 12.5ft:=
Storm Surge (1 year) SS 0ft:=
Maximum Wave Height Hmax 11.2ft:=
Maximum Water Depth dmax dnom HAT+ SS+Hmax
2+:=
dmax 83.7 ft=
Minimum Water Depth dmin 0ft:=
Usage Factor (according to DNV 81Section 4 Table 4.1)
ηh_1 0.72:=
ηh_2 0.5:=
Gravity g 32.174ft
s2
=
Temperatur Derating Faktor kt 1:=
Seawater Density ρsw 64lb
ft3
:=
Maximum External Pressure Pe_max ρsw g⋅ dmax⋅:=
Pe_max 37.2 psi=
Minimum External Presure Pe_min ρsw g⋅ dmin⋅:=
Pe_min 0=
Pressure Design (hidrotes) Pd 323psi:=
Outside Diameter D 32in:=
Corrosion Allowance CA 0.125in:=
Tsweet 0.7 CA⋅:=
Material API 5L X‐52
Spesified Minimum Yield Stress SMYS 52000psi:=
Modulus Elasticity E 3.01 107
× psi:=
CALCULATIONS:
1. Standard DNV 81
Zone 1
Minimum Req. Wall Thickness tDNV_1Pd Pe_min−( ) D⋅
2 ηh_1⋅ SMYS⋅ kt⋅:=
tDNV_1 0.138 in=
Nominal Wall Thickness tnom_1_DNV_sw tDNV_1 Tsweet+:=
tnom_1_DNV_sw 0.226 in=
Zone 2tDNV_2
Pd Pe_min−( ) D⋅
2 ηh_2⋅ SMYS⋅ kt⋅:=Minimum Req. Wall Thickness
tDNV_2 0.199 in=
Nominal Wall Thickness tnom_2_DNV_sw tDNV_2 Tsweet+:=
tnom_2_DNV_sw 0.286 in=
2. STANDARD ASME B31.8
Longitudinal Joint Factor E1 1:=
S1 0.72 E1⋅ SMYS⋅:= S1 3.744 104
× psi=
Design Hoop Stress
Minimum Wall Thickness tASMEPd D⋅
2 S1⋅:= tASME 0.138 in=
Nominal Wall Thickness tnom_ASME_sw tASME Tsweet+:=
tnom_ASME_sw 0.226 in=
SUMMARY AND CONCLUSION:
DNV 81
Zone 1 tnom_1_DNV_sw 0.226 in=
Zone 2 tnom_2_DNV_sw 0.286 in=
ASME B31.8
tnom_ASME_sw 0.226 in=