Design of Uncased Pipeline Crossings

GPTC GUIDE, APPENDIX G92-15, DESIGN OF UNCASED PIPELINE CROSSING

This method is proven and acceptable and can be used in the cases when the crossing conditions for design are out of the scope and the limitations of API RP 1102 and PCPISCES.

𝑆_𝑇 − Total Calculated Combined Stress(psi)(≤100% of SMYS)

𝑆_𝐼 − Hoop Stress due to Internal pressure(psi)

𝑆_𝐸 − Hoops Stress due to External Loading(psi)(based on procedure developed by M.G. Spangler)

𝑃 − Internal Pipe Pressure(psig)(may not exceed pressure calculated in accordance with CFR 192)

𝐷 − Outside Pipe Diameter(in)

𝑡 − Nominal Pipe Wall Thickness(in)

𝐾_𝑏 − Bending Parameter(from GPTC table)

𝑊 − Total External Load(,lb-linear.in of pipe)(includes soil dead load and vehicular live load)

𝐸 − Modulus of Elasticity for Steel(psi)(30 x 10⁶)

𝐾_𝑧 − Deflection Parameter(from GPTC table)

𝐶_𝑑 − Load Coefficient(from GTPC table)

𝛿 − Unit Weight of Soil(lbs/ft³)

𝐵_𝐷 − Width of Pipe Trench or Diameter of Bored Hole(ft)

𝐿 − Wheel Load(lbs)(the maximum wheel loading allowed by governing authority should be used)

𝐼 − Impact Factor,(𝐼=1.5 should be used for nonrigid pavement, and 𝐼 − 1.0 for rigid pavement)

𝐻 − Height of Soil over Pipe(ft)

Input Parameters

1. To create a new case, click the “Add Case” button
2. Select the GPTC Guide, Appendix G92-15, Design of Uncased Pipeline Crossing application from the Pipeline Crossing module.
3. Enter Case Name, Location, Date and any necessary notes.
4. Fill out all required fields.
5. Make sure the values you are inputting are in the correct units.
6. Click the CALCULATE button.

• Nominal Pipe Size(in):(1/8” – 48”)
• Pipe Wall Thickness(in):(0.068”- >2”)
• F- Design Factor: Reference 49 CFR 192.611
• E – Longitudinal Joint Factor
• T – Temperature Derating Factor
• Uniform Support Under Pipe and Crossing Condition
• Soil Type
• Impact Factor
• Pipe Outside Diameter(in):(0.625” – 48”)
• Specified Minimum Yield Strength
• Modulus of Elasticity for Steel
• Unit Weight of Soil
• Deflection Parameter
• Bending Parameter
• Impact Factor
• Pipe Internal Pressure
• Wheel Load
• Width of Pipe Trench or Diameter of the Bore
• Height of Soil Over PipeB13B138:B147
• Nominal Internal Diameter
• Test Pressure
• Test Temperature
• Pipeline Length

Outputs/Reports

1. View the results.
2. If an input parameter needs to be edited be sure to hit the CALCULATE button after the change.
3. To SAVE, fill out all required case details then click the SAVE button.
4. To rename an existing file, click the SAVE As button. Provide all case info then click SAVE.
5. To generate a REPORT, click the REPORT button.
6. The user may export the Case/Report by clicking the Export to Excel/PowerPoint icon.
7. To delete a case, click the DELETE icon near the top of the widget.

• Load Coefficient
• Total External Load
• Hoop Stress Due to Internal Pressure
• Hoop stress Due to External Loading
• Total Calculated Combined Stress

Related Links