The pipe alignment, undertaken on behalf of Unitywater, went under the Bruce Highway and an adjacent creek. UEA Trenchless previously undertook a horizontal investigative bore that was completed successfully, confirming ground conditions as clay and decomposed sandstone.
UEA Trenchless used a guided boring machine (GBM) to place pilot tubes along the centre of the alignment. The pilot tubes were followed by a 450 mm diameter auger bore, which placed a steel case ready to envelop the DN350 polycrete product pipe.
The accuracy of the pilot bore allowed the insertion of a comparatively small diameter enveloper, which allowed a 30 mm annulus to the product pipe. UEA said that a traditional steering method would have required a 600 mm diameter enveloper at minimum to allow for vertical inaccuracies.
The product pipe was inserted and grouted into position marking the completion of the pipe installation.
UEA said it had partnered with CLM Infrastructure to deliver a solution for inserting small diameter pipe on very flat grades over long distances.