Pipe in a Pipe with a Temporary Outer Casing
The methodology below shows how pezzimenti utilises a retractable microtunnelling head for the Pipe in a Pipe Bore Section – where a carrier pipe is sliplined into an outer casing pipe.
+ Pipe in a Pipe Bore Section
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01. Microtunnel
The retractable microtunnelling head is launched from the entry shaft inside the first sleeve.
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02. An Obstruction Encountered
In the event that an an obstruction is encountered, ground conditions change or the head requires repair – the microtunnelling head can be retracted – while the outer casings remain in place to support the ground.
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03. Situation Remedied
Once the Obstruction has been removed, the Cutters replaced to match ground condition or the microtunnelling head has been repaired – the microtunnelling head is pushed back to the face and microtunnelling recommenced.
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04. Bore Completed
The microtunnelling head can be removed via the exit Shaft OR retracted back to the launch shaft. Outer casing is now in place.
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05. Recycle the Outer Casings
The permanent outer casing pipes are jacked in to replace the temporary outer casings, e.g. temporary steel casings are replaced by concrete pipes under a railway line
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06. Slipline the Carrier Pipe
The carrier can is now sliplined into the outer casing and the annulus grouted as required. Microtunnel complete.
Book a Presentation
For futher information on Retractable Microtunelling Head Capabilities and Methodologies book a presentation for your design team with Pezzimenti today. Call Scott Wells on: +61 (2) 4735 6676 or email scott.wells@pezzimenti.com.au