Download - HDD Installation Calculations
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Pipe, Operational, Installation & Site Characteristics Values Units Values Units
Steel Grade 9
Specified Minimum Yield Strength SMYS 450.00 N/mm2 70049.49 lb/in2
Young's Modulus Es 200.0E+3 N/mm2 29,006,000 lb/in2
Poisson's Ratio v s 0.30
Coefficient of Thermal Expansion T 1.17E-05 per oC
Design Stress Factor F 0.72
Outside Diameter D 28.00 inches 711.20 mm
Wall Thickness tw 22.20 mm 0.874 in
Depth H 15,000 mm
Bored Diameter and Type Bd 1,066.80 mm Type: HDD
Maximum Allowable Operating Pressure P 86.00 barg 8.60 N/mm2
Temperature at time of Installation Tmax 30.00 oC 86.00
Design Temperature Max Tmax 50.00 oC 122.00 oF
Design Temperature Min Tmin 15.00 oC 59.00 oF
Temperature Derating Factor T 1.000 (B31.8 Table 841.116A)
Spec & Pipe Class 19.00
Longitudinal Joint Factor E 1.00 (B31.8 Table 841.115A)
HDD Rig size Fr 200.00 tons
Rig Pulling factor Sr 75.00 %
Allowable tensile stress factor Ft 0.40
Time under tension design factor St 0.91
Length of Drill L 800.00 m 2,624.64 ft
Total change of angle over L 16.00 degrees
Radius of curvature 1,300.00 m
Horizontal Directional Drill Installation Calculations- based on Tensile strength
ASCE Manuals and reports on Engineering Practice No. 10
Appendix 4 Page 1 of 4 MM-ZTK-1A-ONEP-PLR-CAL-0002
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Horizontal Directional Drill Installation Calculations- based on Tensile strength
1.0 Check Allowable Barlow Stresses (API 1102 Equation 8b) Values Units
Actual Barlow Stress 137.75 N/mm2
Allowable Barlow Stress 324.00 N/mm2
1.1 Installation Stresses- Bending Stress
R A = Maximum Radius of Curvature (inch)-(For 8 Degrees)
L = Length drilled (ft)
Maximum Radius of Curvature in Drilled hole (in) RA 112,859.52 in 2866.63 m
Min.Radius of Curvature in Drilled hole used RD 51,181.10 in 1300.00 m
f b = Longitudinal Bending Stress (lb/in2)
Longitudinal Bending Stress (lb/in2) f b 7,934.26 lb/in
2 54.71 N/mm2
Maximum allowable Bending Stress (lb/in2) F b -9,429.96 lb/in
2 65.02 N/mm2
1.2 Installation Stresses- External Hoop Stress
D/t 50 D/t = 48.20
t = Pipe wall thickness (inch)
P ext = Uniform external Pressure in lb/in2
(Assumed as 7.5-Percent E )E = Modulus of Steel in lb/in
2
Optimum thickness (D/t 50) t 14.224
Pipe wall thickness due to External Hoop Stress t 14.755 mm
Actual Barlow Stress < Allowable Stress
The pipe thickness due to external hoop stress of pipe is determined as follows
The pipe stress due to bending stress of pipe is determined as follows
F b =0.75F y for D/t 1,500,000/F y
F b = [0.84-(1.74F y D)/(Et)]F y for 1,500,000/F y < D/t 3,000,000/F y
F b = [0.72-(0.58F y D)/(Et)]F y for 3,000,000/F y < D/t 300,000
Longitudinal bending stress < Allowable bending stress
Actual thickness > Allowable Thickness
3/1)/864(12/ EPDt ext
688)/( ALR A
)2/()( Db REDf
Appendix 4 Page 2 of 4 MM-ZTK-1A-ONEP-PLR-CAL-0002
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Horizontal Directional Drill Installation Calculations- based on Tensile strength
1.3 Installation Stresses- Tensile Stress
S y = Tensile Yield Factor
S t = Time under tension design factor
T y = Tensile yield strength
F t = Allowable Tensile Stress
Allowable Tensile Stress ft 163.800 N/mm2 23,755.91 lb/in
2
1.4 Installation Stresses- Required Pipe thickness to meet allowable tensile stress
F r = HDD Rig size
S r = Rig pulling factor
F t = Allowable Tensile Stress
D o = Outside pipe diameter
t r = Required pipe wall thickness to meet allowable tensile stress
Pipe wall thickness due to Tensile Stress t r 14.44 mm
Pipe wall thickness to be used t 22.20 mm
1.5 Installation Stresses- Pipe combined installation stress
F t = Allowable Tensile Stress (lb/in2)
f y = Pipe minimum yield strength (lb/in2)
f b = Longitudinal Bending Stress (lb/in2)
F b = Maximum allowable Bending Stress (lb/in2)
f t / 0.9 F y + f b / F b =-0.436943
The pipe stress due to combined stresses is determined as follows
The pipe stress due to pulling tensile stress of pipe is determined as follows
The pipe thickness due to pulling tensile stress of pipe is determined as follows
Actual thickness > Allowable Thickness
Actual thickness > Allowable Thickness
ytyt TSSf
2*)/)/)/((()2/(( 2 pifSFDpitr trro
1/9.0/ bbyt FfFf
Appendix 4 Page 3 of 4 MM-ZTK-1A-ONEP-PLR-CAL-0002
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Horizontal Directional Drill Installation Calculations- based on Tensile strength
2.0 Operating Stresses- Internal Hoop Stress
f h = Pipe hoop stress due to internal pressure (lb/in2)
P int = Uniform internal pressure (lb/in2)
t = Pipe wall thickness (in)
f h 70% SMYS
Pipe hoop stress due to internal pressure f h 19,974 lb/in2
137.73 N/mm2
2.1 Operating Stresses- Combined Operating Stress
For worst case, fc fh ,
f v 45% SMYS
f v = Longitudinal component oF circumferential stress (lb/in2)
f c = Total circumferential stress (lb/in2)
f l = Total Longitudinal stress, fb (lb/in2)
Longitudinal component of circumferential stress f v 3,023.94 lb/in2
20.85 N/mm2 Actual combined operating stress < Allowable combined stress
The pipe stress during operation due to hoop stress is determined as follows
Actual internal hoop stress < Allowable internal hoop stress
The pipe stress during operation due to hoop stress is determined as follows
)2/()( int tDPf h
2/)( lcv fff
)( bcl fVff
2)2/)1[( bhv
fvff
2/)( chv fff
Appendix 4 Page 4 of 4 MM-ZTK-1A-ONEP-PLR-CAL-0002