Sewer Main Upgrade for Victoria Park Development, Zetland
Client: Landcom
Project: Sydney Water Corporation
Project: Upgrade of sewer infrastructure for the Victoria Park Development Zetland
This project involved the upsizing of an existing Sydney Water sewer main using pipebursting. The objective of the project was to increase the capacity of the sewer main with upsized pipe to alleviate potential flow problems to meet the future requirements of the Victoria Park Development. The site for the Victoria Park Development was the former Navy Supply Centre on South Dowling Street, Zetland. The 25 hectare site has road frontages to South Dowling Street, O’Dea Avenue, Joynton Avenue and Link Road in the City of Sydney Council area. Landcom acquired the site in order to transform it into a high quality living and working environment.
Downer PipeTech has been providing pipebursting for the trenchless renewal of water, sewer, stormwater and industrial pipelines in Australia for over 18 years. Pipebursting is one of the few trenchless technologies that provides a completely new pipe without being infl uenced by host pipe conditions. Pipebursting typically includes renewal of all services and connections, ensuring a service life consistent with a new pipe installation upon completion. One of the advantages of pipebursting is the ability to upsize the host pipe. The degree of upsize is primarily limited by surrounding soil conditions, depth and proximity of other services. Besides Sydney Water, work has been performed for other clients including: Wagga Wagga City Council, Toowoomba Council and Wingecarribee Shire Council.
The objective of the project was the upsize replacement of Sydney Water’s southern sewer main to provide the necessary sewer infrastructure for the Landcom Development Park. To achieve this a number of requirements were considered:
- Compliance with Sydney Water technical requirements
- Ascertain the most economical and practical route for the sewer
- Make available the sewer infrastructure within time constraints
Project Profile
Sewer Main Upgrade, Victoria Park Zetland
This project involved the upsizing of approximately 600m of existing NB225mm sewer main to NB300mm whilst remaining operational during the process. This was achieved by installation of a sewer bypass operation and dewatering of excavations was maintained throughout the project. Six separate pipe run installations were required at depths of up to 6m.
Initially for this project, alternate route options were investigated as well as construction options – open cut excavation or pipebursting. The decision was taken to upgrade the existing sewer main via pipebursting although this presented a number of challenges. Some of these included:
- Unknown condition of existing sewer and timber supporting beams
- Structures and buildings constructed along pipeline route
- Water charged and possibly contaminated ground
- Traversing a major stormwater culvert
A detailed risk assessment was performed on both construction methodologies based on these site constraints with pipebursting offering the best solution. The risks were minimised through a collaboration between client and Downer PipeTech, carrying out a thorough site investigation as well as conducting a trial section of approximately 80m prior to completion of the entire scope of works. One of the key benefi ts of pipebursting was the requirement for minimal plant and spoil stockpiles which reduced site activity in an already congested environment and therefore the impact on property owners.
In summary for Landcom “Pipebursting proved to be a successful option for the Victoria Park Southern sewer upgrade. The site situation with the constraints of water charged sandy ground and surrounding industrial buildings dictated that conventional open cut trench and lay method for the sewer upgrade carried a greater risk, time and cost burden than pipe bursting which clearly excelled in this situation. Risk on the project was minimised by using the pipebursting methodology and trial section of pipebursting. Large cost and time savings were made when compared to conventional dig and lay methods.”