To complete the works at Pier Street and Milligan Street in Perth’s CBD, DJ Mac Cormick used a Herrenknecht AVN 600 closed faced laser guided steerable tunnelling machine to install Humes S series stainless steel band concrete jacking pipes.
The launch and receival shafts were constructed at depths of 4-5.5 m below ground level and with a combination of wellpoint and open pumping required at all shaft locations owed to the high groundwater table.
DJ Mac Cormick says the two crossings required detailed analysis and contingencies in place given the rail crossings were more complex due to the numerous lines required to be tunnelled under.
Detailed planning took eight months prior to the project, including detailed project pre-start tunnelling plans drawn up for each crossing to note location stops at every point on a daily basis.
DJ Mac Cormick said all crossings were successfully completed within the allowed shutdown periods of 10pm and 3.30am
The contractor has now successfully undertaken more than 100 rail crossings Australia wide, including 8 in Perth, 5 in Brisbane, 2 in Sydney, 1 in Melbourne and 1 in Townsville in the past 2 years.
For more information visit the DJ Mac Cormick website.
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