UEA Trenchless Division completes GBM/thrust bore project across New England Highway for Knock Contractors in Maitland

Posted 6 February 2015

UEA Trenchless were contracted to undertake a 95 metre under bore of the New England Highway in Maitland and install a 457mm OD steel case enveloper pipe with 6.4mm wall thickness. Following the steel case insertion installation the client supplied the DN225 DICL PN35 carrier pipe on centralisers and grout the annulus between the carrier and steel enveloper pipe.


Techniques Used

The Akkerman Laser Guide Boring Machine (GBM) was used to undertake and complete a successful pilot bore on grade and within the allowable tolerances agreed at design stage.

The McLaughlin conventional Auger Boring machine was used to install the steel enveloper and the client supplied GRP carrier pipe.


The Works

This bore presented a number of challenges from the onset. The tolerances were tight with a grade of 0.33% grade and the ground was very sandy.

Pilot Bore

UEA commenced and completed a successful pilot bore on Tuesday 7thOctober that finished on design grade and the correct alignment – 6mm low within the receipt pit.

Steel Case Insertion

When the pilot bore was complete UEA installed the 96m of steel case in three days using their Mc Laughlin Conventional Auger Borer.


UEA completed the remaining works in one day which was to install the client supplied DN225 DICL PN35 carrier pipe and grout the annulus between the carrier and steel enveloper pipe.


The client was delighted with UEA’s capabilities and was very satisfied with the completed works and the accuracy of the installation. The GBM Technology cannot be surpassed in displaceable ground conditions for bores up to 150m in length.