AGENDA Pipe Materials / Trends The Reason for Change Design / Standards Pipe Selection Installation Examples Conclusion
Water & Sewerage Pipe Materials Flexible Pipes Replacing Rigid Pipes Old Days Vitrified Clay Pipes (VC) Asbestos Cement (AC) Plastic Lined Concrete Steel pipes PVC Today PE -Polyethylene PP - Polypropylene GRP Glass Reinforced Plastic ABS - acrylonitrile butadiene styrene Flexible Pipes Now The Material of Choice
The Reason For Change 1900 1960 2000
Traditional Stormwater Pipe Materials Concrete FRC Corrugated steel pipe
Today we also have- PVC BLACK BRUTE Rib Loc Ribstruct Green Pipe
And BlackMAX
So Why The Reluctance to Use Flexible Pipes Particularly Under Roads Typical misconceptions:- Deflection increases with installation depth and with traffic load. Pipe ring stiffness is the governing factor determining the performance. Pipe loses stiffness with time, the load bearing capacity reduces. To predict the structural performance an extensive design method is needed. You need more care to install a flexible pipe.
Corrugated Steel/Aluminium Pipes The majority of Authorities, including Main Road Department and the Railways. Approve and Use Steel /Aluminium Corrugated Pipe
Corrugated Aluminium / Steel Pipes This is a Flexible Pipe but also The pipe stiffness values are far less than some PVC/PE/PP pipes that are being used today.
Lets Clear Up A Few of These Misconceptions?
The pipe soil interaction Ring deflection of flexible pipes is controlled by the settlement of the soil. After settlement, traffic and other loads do not affect pipe deflection. Deflection is safety! When pipes are relatively more rigid than the soil, the traffic and other loads have to be resisted by the pipe. Imagine the potential
Flexible Pipe Design AS/NZS 2566.1: Buried flexible pipelines Part 1 Structural Design
Computer Programme Pipe Details Embedment Soil Properties Loading Details Detail
The Result View the 3 design criteria Deflection Wall strain Buckling
DON T PANIC Its not that confusing
Design Table/Chart Typical Cover Heights for Common Trench and Embankment Conditions Including Traffic Loading Chart prepared in accordance with AS/NZS256 for the conditions stated.
Pipe Selection Cont. Permissible maximum cover height (m) For practical purposes in average soils with normal attention to selection and compaction of embedment SN4 (4000 N/m.m) is OK to 3 m SN8 (8000 N/m.m) is OK to 6 m Flexible Pipe Selection It s Not New!
For Example in the Sewer Market PVC sewer pipe have been successfully used for over 35 years. Classes used SH(Sewer Heavy) Now Classified as SN4 SEH (Sewer Extra Heavy) Now Classified as SN8
Pipe Selection Cont. Draft Standard AS/NZS 5065 (Publication 05?) - Polyethylene and Polypropylene pipes and fittings for drainage and sewerage applications Outlines Pipe Stiffness Values SN2 SN4 SN8 SN10 and SN16
Installation AS/NZS 2566.2 Buried flexible pipelines Part 2 Installation
Installation Cont. Standards for installation of pipes specify different requirements for flexible and rigid pipes. Despite this installation practice is similar for both pipes. Flexible Rigid Actual
What does this mean? Under roadways, same as Rigid Pipe!
Examples of Flexible Pipes Under Roads 900 Dia Black Brute 600 Diameter Black Brute 8 Years Ago
Lawrence Hargrave Drive, Clifton NSW
Punt Road: Melbourne Victoria DN 1200 Black Brute Installed 1989 (16yrs) 40,000 vehicles /day including trams
Boonah Shire Council 300 and 375 Diameter BlackMAX SN8
Crookwell Road Section of Main Rd Nr Goldburn Benkelman beam measurements -
How much more testing do we need to do? Is that were I left my wallet
TESTING JOINT INTEGRITY Joint Design Resistance to infiltration at -85kPa gauge pressure. Resistance to exfiltration at 85kPa gauge pressure. Both with >7.5% diametric distortion of spigot.
Conclusion Depth and traffic load have no effect on the final deflection. No major difference between a rigid and flexible pipe when installed in a trench or embankment condition. Installation is the same under roadways Ok with high compaction loading.
Confidently Planning For The Future With Flexible Pipes The Ultimate Honour
Queensland The Smart State?