Tiaro

Culvert Installation and Culvert Slipline beneath Bruce Highway

As part of the on-going project to upgrade the Bruce Highway, Pezzimenti were engaged by RoadTek/TMR to install a new 1 x 28m long, 2700mm ID RCJP and slipline an existing Steel corrugated pipe culvert with a 1800 RCJP underneath the dual carriageway at Tiaro, just south of Maryborough, Qld. The 2700 ID pipes were installed by Open Face Pipe Jacking- a method which the crews have perfected over decades.  The primary aims of the project were to safely install the pipes without disrupting traffic while ensuring the integrity of the highway embankment.

A 2-stage thrust block was installed to withstand the expected maximum jacking loads of 180 tonnes. The purpose- modified steerable shield was used to excavate through the damp clay fill embankment.

Establishment and preparing to excavate took 5 days, excavation took 4 days, demobilise took a single day. The maximum recorded jacking load was 130 tonnes, the error in line and level was less than 5mm, traffic continued uninterrupted throughout, and no settlement was recorded.

As part of the same works, an adjacent existing corroded corrugated steel pipe was sliplined with an1800 ID RCJP. The usual process of job preparation was followed to ensure smooth insertion of the new pipes- viz ie the existing culvert was surveyed for misalignments, packers and rails placed to line and level, the pipes pushed and the annulus grouted over 5 days. The sliplining push load was extremely low at approx. 5-10 tonnes.

The technique of Open Face Pipe Jacking has been perfected over many years and hundreds of new culverts have been installed and corroded corrugated steel pipe culverts have been replaced in situ.

When asked to comment on the job the experienced operator replied ‘just another day in paradise’

Open Face Pipejacking – Culvert Installation

Culvert Slipline