Water, Our Focus
Green Square Sewer Carrier Main Relocation
Water, Our Focus
Project Background
The project consisted of 4 mid-rise apartment buildings (up to 23 levels in height) with a total of 342 quality apartments in Portman St, Zetland.
As the project included a 3-storey basement carpark, Mirvac were required to carry out a sewer diversion of the line that was crossing the site.
Project Details
Client
Mirvac
Asset Owner
Sydney Water
Project Dates
September 2019 – January 2020
Location
Zetland NSW
Scope Of Works
Killard Infrastructure delivered the following works:
-
- Caisson shaft installation and construction as the bore launching pit.
- Micro tunnelling works of two 45-metre lines: OD700mm encasing steel pipe and insertion of DN450 GRP sewer carrier pipes.
- 3 x cast-in situ 1800mm internal diam. manhole with HDPE liner constructed up to 9m deep.
- Connection works to the existing sewer infrastructure and disuse of redundant sewer line.
Outcome / Key Features
Killard was awarded the project due to the innovative solution to excavate the shafts.
Due to the new DN1800 manholes being located beneath high voltage power cables, sheet piling or shoring boxes couldn’t be used. To mitigate the risk of overhead electrocution, Killard installed a DN5500 segmental steel caisson shaft using an excavator with a telescopic arm. The two receive pit excavations were dug on top of the existing sewer line to allow the construction of the new manholes.
Management of traffic and residents as two of the shafts, including the 9-metre-deep shaft, were in the middle of the road in a busy area of Sydney.
Bypass installation and management to carry out the connections to the existing sewer network done safely and on time during one 12-hour nightshift with the supervision of Sydney Water.
