Pezzimenti Tunnelbore completed a total of 32 microtunnels for a total of 366m ranging in diameter from Ø440 to Ø1000mm inside and during the construction of the twin Clem 7 Tunnels which pass under the Brisbane River.

SWGC Microtunneling Method Free Pipe

SWGC Microtunneling Diameter Length Ground

Microtunnels to connect High Voltage switch rooms

During the design phase the Leighton Contractors and Baulderstone Hornibrook Bilfinger Berger Joint Venture (LBBJV) realised that a series of microtunnels in the congested confines of tunnels would require equipment which had the strength to cut through the hard rock yet be versatile enough to be able to gain access to the site without interfering with the construction of the main tunnel.

After consulting with Pezzimenti, the various cross-passages linking the 2 main tunnels were designed to accommodate Pezzimenti equipment. Microtunnels linking the cross-passages were required for the high voltage supply for the operating tunnel.

Radial Bores microtunnelled at low points

Clem 7 has 2 low points and at each low point storm water is collectedand pumped from the tunnel. At each low point a series of radial bores from a single shaft were drilled in order to collect the stormwater from the main tunnels. Flanged Ductile Iron pipes were then inserted into the bores.

Clem7 Roadt Tunnel Pezzimenti Microtunneling Vacuum Unit Being Craned

The modular hydraulic power pack being craned for transport into the tunnel


The craneage setup for the microtunnels to link adjacent passages

Clem7 Road Tunnel Pezzimenti Microtunneling Elevated Jacking Frame

Jacking frame sitting on top of support frame

Clem7 Road Tunnel Pezzimenti Microtunneling Elevated Jacking Frame

Microtunnelling the higher level bore to the next cross passage

Clem7 Road Tunnel Pezzimenti Microtunneling Head Ready To Launch On Elevated Jacking Frame

The yellow tunnel lining had to be removed to enable microtunnelling to be received.


Setup of the crane truck within Clem 7

Clem7 Road Tunnel Pezzimenti Microtunneling Drilling Operator

Microtunnelling the radial drainage lines in the low point sump


Completion of one the radial bores can be seen to the right of the jacking frame


Very hard quartz rich igneous rock was encountered. Location of a rock bolt now removed can be seen at 1 oclock on the bore


Close up of the ground and drilling rods.