PE Pipe – Post Installation Loads and Deflections

Post Installation Loads and Deflections

Earth Pressure Coefficient:

Θ – Internal Friction Angle of Soil (degree)

Arching Factor:

H – Depth of the Borehole below Ground Surface (ft)
B – Internal Bore Diameter (inch)
δ = Θ

External Earth Pressure:

γ – Unit Weight of Soil (lb/ft3)

Net External Pressure:

External Pressure Deflection:

E – Apparent Modulus of Elasticity (psi)
DR – Standard Dimensions Ratio

Buoyant Deflection:

γ_w – Unit Weight of Fluid in Borehole (lb/ft3)
D – Pipe Outside Diameter (inch)
I – Moment of Inertia of the Pipe Cross-Section (inch4/inch

t – Pipe Wall Thickness (inch)

Deflection due to Reissner Effect:

μ – Poisson’s Ratio
R- Radius of Curvature (ft)

Ovality Compensation Factor:

f₀ – Ovality compensation factor based on % of Deflection (𝑃𝑒𝑟𝑐𝑒𝑛𝑡 𝑜𝑓 𝑂𝑣𝑎𝑙𝑖𝑡𝑦)

Critical Collapse Pressure:

Safety Factor Against Buckling:

Input Parameters

Internal Bore Diameter (inch)
Depth of the Borehole below Ground Surface (ft)
Unit Weight of Fluid in Borehole (lb/ft3)
Unit Weight of Soil (lb/ft3)
Internal Friction Angle of Soil (degree)
Pipe Outside Diameter (inch)
Standard Dimensions Ratio
Percent of Ovality
Apparent Modulus of Elasticity (psi)
Poisson’s Ratio
Radius of Curvature (ft)
Live Load (lb/ft2)

Outputs/Reports

Earth Pressure Coefficient
Arching Factor
External Earth Pressure (psi)Net External Pressure (psi)
External Pressure Deflection (percent)
Buoyant Deflection (percent)
Deflection due to Reissner Effect (percent)
Ovality Compensation Factor (percent)
Critical Collapse Pressure (No Safety Factor) (percent)
Safety Factor Against Buckling

Related Links

Horizontal Directional Drilling Plastic Pipes

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