UEA Trenchless has recently been awarded the construction of 883 metres of a 710mm water main and two 140mm communication lines. The works include two bores alongside one another for both the water main and communication line. These works form a part of the Mount Piper Water Treatment Project that will deliver water between the Springvale Mine and the Mount Piper Power Station.
The location of these bores will start at Wolgan Road and will run adjacent to the coal conveyor belt. Works will pass through the Castlereagh Highway, under the Coxs River and railway and will finish in open land acquired by the Mt Piper Power Station. As the bores pass through Castlereagh Highway it is expected to miss bridge piles.
UEA will utilise both the Gallagher 660 drill rig and Vermeer D330 drill rig to undertake both bores, due to the distance of the bore and the expected ground conditions of sandstone and siltstone. Both the geotechnical report and the bore design indicate that the drill will most predominantly remain within the sandstone and siltstone rock layers along the alignment.
Before construction, UEA undertook a site visit to survey the area, as well as the preparation of documents such as Risk Assessments, SWMS, ITPs, Safety Data Sheet, and safety and quality management plans.
UEA has developed the bore design for both client and RMS approval, as the bores will be crossing a highway, river and railway. The design had to adhere to certain limitations, such as being located well underneath the piles at the bridge on Castlereagh Highway while ensuring the bore is within the pre-determined easement. Due to design limitations and minimal space at the entry of the HDD, UEA proposed that space between the water pipe and communication line bore be a minimum of 1.5 metres. Where separation between the two bores cannot be maintained horizontally, the communications bore will be brought underneath the water bore to maintain pipe within the easement. As the surface levels vary, and the site has some restrictions (densely vegetated and in close vicinity to existing infrastructure, i.e. conveyor belts), UEA is also assisting the client to design and construct additional underbores in other sections of the project.
For more details on this project, or on UEA’s additional horizontal directional drilling projects, contact the Trenchless team or call us on 02 9672 4456.