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Project

Pipe details

DN mm

Summary

Outside diameter

Dₑ

428

mm

Inside diameter

Di

374

mm

Diameter at neutral axis of wall

D

393

mm

Initial 3-minute ring-bending modulus

Eb

1207

MPa

Long-term ring-bending modulus

EbL

200

MPa

Poisson's ratio

μ

0.45

Initial 3-minute ring-bending stiffness

SDI

8000

N/m/m

Long-term (2 year) ring-bending stiffness

SDL2

1904

N/m/m

Long-term (50 year) ring-bending stiffness

SDL50

1325

N/m/m

Site conditions

B mm
(input only if trench width is wider than what the minimum is required)
H 0.8 m
H0.5 m H9.0 m
*For cover heights less than 0.5m please contact Vinidex
H w 0 m
Hw0 m Hw9.0 m

Summary

Trench width

B

828

mm

Embedment material modulus

E'ₑ

7

MPa

(subject to confirmation by geotechnical testing)

Native soil modulus

E'ₙ

3

MPa

(subject to confirmation by geotechnical testing)

Soil specific weight

γ

21

kN/m3

Soil particle specific density

2.65

Design dead loads and live loads

w gs 0 kPa
w gs 0 kPa w gs 400 kPa

Summary

Vertical design load (pressure at top of pipe) due to surface-applied live load

wq

96

kPa

Vertical design load (pressure at top of pipe) due to soil dead load ¹

wg

13

kPa

Effective combined soil modulus

Summary

B/Dₑ

1.9

E'ₑ/E'ₙ

2.3

Bedding constant

K

0.1

Design factor

Δf

0.6

Leonhardt correction factor

ζ

0.56

Effective combined soil modulus

E'

3.9

MPa

Deflection prediction

Maximum allowable long-term vertical deflection

Δyall/D

7.5%

Predicted long-term vertical deflection

Δy/D

4.3%

Strain prediction

Shape factor

Df

4.32

Maximum allowable long-term ring-bending strain

ᵋball

4%

Predicted long-term ring-bending strain

ᵋb

1.6%

Buckling stability

Minimum allowable design factor for buckling

Fₛₐₗₗ

2.5

Submerged density

13.1

kN/m3

Buckling pressure for H>Hw (excluding vacuum pressure)

qb

114

kPa

qₐₗₗ₁

23

kPa

qₐₗₗ₂

123

kPa

Allowable buckling pressure (greater of qall1 or qall2)

qₐₗₗ

123

kPa

Actual design factor for buckling (excluding vacuum pressure)

Fₛ

2.7

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Notes

  1. Soil loading on the pipe is calculated based on the prism load and ignores the effects of soil friction within the fill above the pipe.
  2. Design loads on buried flexible pipelines, due to construction and other equipment, should be determined as they can exceed the loads that apply following the construction phase. It is the designer’s responsibility to check the type of equipment to be used during construction, particularly when the cover tends towards the minimum. Allowance should be made for increased impact effects due to adverse surface conditions. It may be necessary to increase the cover locally to reduce the working loads due to construction and other equipment
  3. The 2-year value for the ring-bending stiffness of the pipe may be used to represent the design basis of 50-year deflection, ring-bending strain and buckling response.
  4. The ring bending modulus values are based on the AASHTO LRFD Bridge Design Specifications for corrugated PP and PE pipe.

*Disclaimer

The information contained in the guidelines is based on the Australian standard AS/NZS 2566.1 “Buried flexible pipelines. Part 1: Structural design”. Vinidex is providing this information as a guide and this is provided in good faith to assist users in obtaining the best performance of Vinidex products. Vinidex makes efforts to align information in the tool with the Australian standard above, but does not take responsibility for the accuracy of the information or the results of using the guideline. The guidelines are provided to be a general guide in determining design of buried flexible pipelines but cannot include the complex details of the specific installation. Application of the information may involve engineering judgements which cannot correctly be made without detailed knowledge of all conditions pertaining to a specific installation. Responsibility lies solely with the user to ensure the applicability of the information in the context of those circumstances. It is recommended that advice be obtained from a consultant registered with the Institution of Engineers.No warranty (other than Statutory warranty) is expressed or implied as to the content of the information or results obtained by use thereof, and Vinidex Pty Limited will not be held liable for any costs or damages, direct or indirect, that might arise from use of the guidelines. These terms and conditions are governed by the laws of New South Wales.