PROJECT OVERVIEW.
Capability and favourable ground reduces design cost
Past experience in the area suggested the clay was quite stiff and would be temporarily self-supporting while the pipe was being inserted (approx 2 days) prior to grouting. This meant that the steel sleeve casing, which was included in the original design, was not required which significantly reduced time and project cost. As the bores were relatively short the risk was minimal, given the favourable ground conditions.
4m x 2m shaft capability ensured minimal impact
Only one bore required steel sleeve, as a leaky water main adjacent made the ground saturated and the roof of the bore fretted falling onto the drilling rod – blocking the laser. Being 375 and 430 bores meant that Pezzimenti could fit into smaller shafts – 4m long by 2m wide which was beneficial in the built up area with adjacent services and footpaths. The modular nature of the Pezzimenti Tunnelbore equipment minimised impact on parkland environments and the community.
The map of 446 metres of microtunneling completed across 10 tunnels.
Looking down Swinden street towards microtunnel 2, 3 and 4.
Driller loads a drill rod onto the jacking frame.
Gantry and Vacuum Truck setup adjacent to road at Pit 8.
Top man lowering drill rod to thaft using Gantry winch.
Driller commences drilling after loading a drill rod
Completed Microtunnels on Swinden Street – Pits 2, 3, 4, 5
UPVC Carrier Pipe sliplined into completed microtunnel and at rest.
PVC Carrier Pipe sliplined into completed microtunnel and at rest
Progress of manholes after microtunnelling completed.
MICROTUNNEL 1.
Pipe in a Pipe by Freebore Method
Length. 46.5m
Diameter. 430
Ground. Clay
Casing Pipe. 408 Steel
Carrier Pipe. 300 uPVC
MICROTUNNEL 2.
Free Pipe by Freebore Method
Length. 60m
Diameter. 375
Ground. Clay
Casing Pipe. None
Carrier Pipe. 300 uPVC
MICROTUNNEL 3.
Free Pipe by Pipejack Method
Length. 82
Diameter. 375
Ground. Clay
Casing Pipe. None
Carrier Pipe. 300 uPVC
MICROTUNNEL 4.
Free Pipe by Freebore Method
Length. 26m
Diameter. 375
Ground. Clay
Casing Pipe. None
Carrier Pipe. 300 uPVC
MICROTUNNEL 5.
Free Pipe by Freebore Method
Length. 56m
Diameter. 375
Ground. Clay
Casing Pipe. None
Carrier Pipe. 300 uPVC
MICROTUNNEL 6.
Free Pipe by Freebore Method
Length. 47m
Diameter. 375
Ground. Clay
Casing Pipe. None
Carrier Pipe. 300 uPVC
MICROTUNNEL 7.
Free Pipe by Freebore Method
Length. 18m
Diameter. 470
Ground. Clay
Casing Pipe. None
Carrier Pipe. 375 uPVC
MICROTUNNEL 8.
Free Pipe by Freebore Method
Length. 52m
Diameter. 470
Ground. Clay
Casing Pipe. None
Carrier Pipe. 375 uPVC
Length. 52m
Diameter. 470
Ground. Clay
Casing Pipe. None
Carrier Pipe. 375 uPVC
MICROTUNNEL 9.
Free Pipe by Freebore Method
Length. 40m
Diameter. 440
Ground. Clay
Casing Pipe. None
Carrier Pipe. 375 uPVC
MICROTUNNEL 10.
Free Pipe by Freebore Method
Length. 18m
Diameter. 440
Ground. Clay
Casing Pipe. None
Carrier Pipe. 375 uPVC