Calculations
Pipe Database
Charts
Notes
Key Standards
Ready to calculate
Work through the steps on the left, then hit Run Calculation. Your full design check will appear here with step-by-step arithmetic and clause references.
1Search the pipe database or enter properties manually
2Set installation conditions, soil moduli, and cover depth
3Enter design loads — earth, live, and working pressure
4Run calculation — review results and export to PDF
Pipe Database (click row to apply)
⚠ Database values are indicative only. SDL is the nominal product stiffness class. E_bL and t vary by manufacturer. Always confirm with current product data sheets before design submission.
| Apply | Name ↕ | Material | De (mm) | t (mm) | SDL (N/m/m) | E_bL (MPa) | ν | P_all (kPa) |
|---|
Utilisation Summary
all design checks — <1.0 = pass
≤ 70% util
70–100%
> 100% fail
Deflection vs Cover Depth
Δy/D sweeping H from 0.3–10 m (all other inputs fixed)
Run calculation to populate chart
Deflection vs Effective Soil Modulus E′
Δy/D sweeping E′ from 0.5–25 MPa (at current load)
Run calculation to populate chart
Standard: AS/NZS 2566.1:1998 Buried Flexible Pipelines Part 1: Structural Design, incorporating Amendment No. 1 (reconfirmed 2018).
Implemented Equations
| Eq. 5.2(2) | Deflection Δy/D | K·w / (8×10⁻⁶·SDL + 0.061·E′) |
| Eq. 5.3.1(2) | Ring-bending strain ε_b | Df·(Δy/D)·(t/De) |
| Eq. 5.3.1(3) | Shape factor Df | Rational function of SDL/E′ |
| Eq. 5.3.3 | Combined loading | (Δy/Δy_all)² + (ε_b/ε_all)² ≤ 1 |
| Eq. 5.4(4) | Buckling q_all1 | 24·SDL / (Fs·(1−ν²)) × 10⁻³ |
| Eq. 5.4(5) | Buckling q_all2 | SDL^(1/3)·(E′×10⁶)^(2/3) / (Fs×1000) |
| Eq. 3.4.3(1) | Effective soil modulus | E′ = ζ·Ee |
| Eq. 3.4.3(2) | Leonhardt ζ factor | 1.44 / (1.44·En/Ee + B/De − 1) |
| Eq. 4.7.2(1) | Live load dispersal | wq = α·P / (L₁·L₂) |
| Eq. 4.7.2(2) | Impact factor α | max(1.4 − 0.15H, 1.1) |
| Cl. 4.3 | Prism earth load | w_e = γ·H |
| Cl. 4.3 | Marston trench load | w_e = Cd·γ·B²/De |
⚠ Leonhardt ζ deviation: This calculator applies the groundwater correction factor (f_gw) to Ee before computing ζ, which departs from the literal Eq. 3.4.3(2) sequence but provides more conservative results when GW is above pipe centreline. Engineers should verify this assumption against project-specific conditions.
⚠ Bedding constant K: Clause 5.2 states "K is assumed to be 0.1 unless detailed engineering assessment shows otherwise." The Table 4.1 values (e.g. 0.096 for 45°) are technically valid but require engineering justification to deviate from the Cl. 5.2 default.
Scope (Cl. 1.1): This standard applies to buried flexible pipelines with: OD ≥ 75 mm, SDL ≥ 625 N/m/m, SDL per unit pipe length ≥ 1250 N/m/m.
Key Standards Reference
Values per AS/NZS 2566.1:1998 (incorporating Amendment No. 1). These values were corrected in Rev 8.7 from earlier conservative non-standard values — all values below are as published in the standard.
Table 2.1 — Allowable Long-Term Deflection & Ring-Bending Strain
| Material | Δy_all / D (%) | ε_b_all (%) | Notes |
|---|---|---|---|
| PVC-U | 7.5 | 1.0 | Table 2.1 row 3 |
| PVC-M | 7.5 | 1.0 | Table 2.1 |
| PVC-O 400/450/500 | 7.5 | 1.3 | MRS class discrimination per Table 2.1 |
| PE100 | 7.5 | 4.0 | Table 2.1; strain typically governs for profile walls |
| PE80 | 7.5 | 4.0 | Table 2.1 |
| PP-B | 7.5 | 4.0 | Non-pressure applications only (NA for pressure) |
| ABS | 7.5 | 1.0 | Table 2.1 |
| GRP-UP | 6.0 | 0.6 | Strain typically governs; wide range of stiffness classes |
| DI | min(4%, 0.056·De/t) | N/A | Unlined/flexible lining. CML/elastomeric: see Appendix B. |
| MSCL | min(4%, 0.056·De/t) | N/A | Same formula as DI |
| Steel (unlined) | 5.0 | N/A | CML/elastomeric lining: min(4%, 0.00014·YS·D/t) |
⚠ Note (corrected in Rev 8.7): Versions prior to Rev 8.7 used conservative non-standard values (PVC: 5%, PE/PP: 3%, GRP: 3%/0.2%). These have been corrected to match Table 2.1 of AS/NZS 2566.1:1998 (Amdt 1).
Table 3.1 — Minimum Cover
| Location | Min. Cover H* (m) |
|---|---|
| Not subject to vehicular loading | 0.30 |
| Subject to vehicular loading — not in roadways | 0.45 |
| Subject to vehicular loading — in sealed roadways | 0.60 |
| Under unsealed roadways | 0.75 |
| Pipes in embankment or subject to construction equipment | 0.75 |
*Subject to variation by regulatory authority.
Key Standards Referenced
| Standard | Scope |
|---|---|
| AS/NZS 2566.1:1998 | Buried flexible pipelines — structural design (this calculator) |
| AS/NZS 2566.2 | Buried flexible pipelines — installation |
| AS/NZS 1477 | PVC-U pressure pipe and fittings |
| AS/NZS 1260 | PVC-U pipes for drain, waste and vent |
| AS/NZS 4765 | Modified PVC (PVC-M) pipes |
| AS 4441 | Oriented PVC (PVC-O) pressure pipes |
| AS/NZS 4130:2018 | Polyethylene (PE) pipes for pressure applications |
| AS/NZS 4131 | PE compounds for pressure pipes and fittings |
| AS 3571.1 / 3571.2 | GRP piping systems — drainage/sewerage and water supply |
| AS 2280 | Ductile iron pressure pipes and fittings |
| AS 1579 | Arc-welded steel pipes — water and wastewater |
| AS/NZS 4020 | Testing of products for use in contact with drinking water |