PROJECT OVERVIEW.

As part of the on-going redevelopment of the former Australian Defence Industry site, Lend Lease required installation of a deep sewer (up to 11m).

Jordan Springs Microtunneling Method Freebore

Jordan Springs Microtunneling Length Diameter Ground Conditions

Project Overview

The total length of the line required 870 lineal metres of 450mm diameter GRP pipe encased with a Ø660 steel casing. The maximum length of a single drive was 180m. The grade was designed at the very flat value of 0.240%. Lend Lease awarded the works which included open cut sections to Trazlbat. Trazlbat subcontracted the microtunnelling to Pezzimenti Tunnelbore.

Self-Supporting Ground Conditions

The ground was a weathered shale to clay. The first 4 microtunnels were created using the freebore method, then the steel casing was inserted, followed by the pipes and the annular void grouted. The last bore in clay was pipejacked to maintain stability of the bore during microtunnelling.

Jordan Spring Pezzimenti Microtunnelling Site Layout

Site Set-up: The top section of the ground was cut down to allow excavation of the lower 6 metres of the shaft.

Jordan Springs Microtunnelling Freebore

Freeboring in shale

Jordan Springs Microtunnelling Slipline Outer Casing into Freebore

Piepejacking the steel casing in ground which was not self-supporting.

Jordan Springs Microtunnel Slipline Carrier Pipe

Sliplining a SN20,000 GRP collared Pipe

MICROTUNNEL 1.

Microtunneling Pipe in a Pipe Icon
Pipe in a Pipe by Freebore Method

Length. 175m
Diameter.  690
Ground. Sandstone / Shale
Casing Pipe. 660 Steel
Carrier Pipe.  450 GRP SN20K
Grade 0.26%

MICROTUNNEL 2.

Microtunneling Pipe in a Pipe Icon
Pipe in a Pipe by Freebore Method

Length. 145m
Diameter.  690
Ground. Sandstone / Shale
Casing Pipe. 660 Steel
Carrier Pipe. 450 GRP SN20K
Grade. 0.26%

MICROTUNNEL 3.

Microtunneling Pipe in a Pipe Icon
Pipe in a Pipe by Freebore Method

Length. 175m
Diameter.  690
Ground. Sandstone / Shale
Casing Pipe. 660 Steel
Carrier Pipe. 450 GRP SN20K
Grade. 0.26%%

MICROTUNNEL 4.

Microtunneling Pipe in a Pipe Icon
Pipe in a Pipe by Freebore Method

Length. 174m
Diameter.  690
Ground. Sandstone / Shale
Casing Pipe.  660 Steel
Carrier Pipe.  450 GRP SN20K
Grade 0.24%

MICROTUNNEL 5.

SWGC Microtunneling Pipe in a Pipe
Pipe in a Pipe by Pipejack Method

Length. 176m
Diameter.  690
Ground. Clay / Shale
Casing Pipe.  660 Steel
Carrier Pipe. 450 GRP SN20K
Grade. 0.24%

Pezzimenti Tunnelbore Jordan Springs Case Study Download