A small residential development at Kellyville required the existing sewer system to be extended with Ø300 main for a distance of 318 metres, with 109 metres to be microtunnelled.

SWGC Microtunneling Method Free Pipe

SWGC Microtunneling Diameter Length Ground

Microtunneling Under Conservation Zone

The downstream section from Ch 21 to 130m crossed under a drainage reserve/tree conservation zone. This section was microtunnelled in 2 microtunnels: 50m long @ 1.04% and 59m long @1.02%. The ground was a mixture of clay and shale.

Freebore in Self-Supporting Ground

The designer specified a 500mm outer steel casing with a Ø300mm carrier. Both sections were firstly freebored as the ground was self-supporting. Despite the absence of a need for an encasing pipe, the steel casing was sliplined into the microtunnel as per the designer’s request and then followed by the carrier pipe. The annular space was grouted.

Kellyville microtunneling pezzimenti site layout

Site Setup with the Crane Truck

Kellyville Pezzimenti Microtunneling setting up the jacking frame

Setting up on the shoring at a manhole which has a change of direction. 

Kellyville Microtunneling Pezzimenti Head break through into shaft


Kellyville Microtunneling Pezzimenti Download Case Study