GFWAust have been identified as a preferred contractor for backfilling electrical bores for Energy Australia
Berowra:
As part of the upgrade to supply electricity to the new Epping to Chatswood Railway the Berowra substation was upgraded. This included the provision of a connection across the Pacific Highway to Berowra NE railway line.This required the installation of a 50m long 450mm diameter bore beneath the highway to take 4No. 150mm conduits and two 63mm diameter conduits.GFWA were appointed to grout up the bore to ensure the conduits were fully enclosed with a high quality non-shrink grout with a thermal rating of 1kW/m.The bore was successfully filled over two days through two injection pipes using low viscosity high strength grouts.
Argenton:
To provide additional power to Warratah Engineering Works on Lake Macquarie it was necessary to provide three electical bores beneath Lake Road at Argenton. Lake Road is a busy arterial road between Lake Macquarie and Newcastle and therefore open trenching was not possible. GFWAust were appointed to backfill each of the three bores with a total of 30m3.
The bores were 25m long, 900mm diameter containing between 7 to 12 160mm conduits – requiring about 10m3 of backfill per bore. Due to problems of heat of hydration of the cement melting the conduits, GFWAust trialed a low heat grout to fill the bores successfully.
Lake Munmorah
UEA constructed three 450mm unlined bores up to 50m long under the Pacific Highway at Lake Munmorah. These bores were then installed with 4 No 180mm diameter conduits and a 65mm diameter conduit. GFWAust were appointed to determine a grouting method to backfill the remaining void. The bores were successfully filled using a low viscosity grout in a National Park with particular environmental control.
Lane Cove Road
With the major industrial development at Macquarie Park following completion of the Epping to Chatswood Railway new energy infrastructure was required. To enable Energy Australia to install the electrical cables underground, Austberry drilling were appointed to bore beneath the busy junction of Lane Cove Road and Waterloo Road. A 800mm diameter bore was installed with 6 No 180mm diameter ducts over a length of 125m. The bore was required to descend to a maximum depth of 9m at the lowest point beneath the junction to avoid water and gas mains.
GFWAust were appointed to fill the bore with a quality grout with a thermal rating of 1kW/m to surround the conduits. The total volume of grout required was 0ver 40,000 litres and all work was required to be carried out on night shift due to heavy traffic conditions.
The work was successfully completed with a non shrink grout to provide a fully grouted bore with minimum interference on the local area.
Darley Road, Manly
Due to overheating of the main cable along Darley Road, GFWAust were appointed to fill the conduit around the cable. The 100mm diameter conduit with a 75mm conduit inside was filled with a fluid, non-shrink grout to ensure the conduit was completely filled
To remove the overhead power supply to the BHP site on Kooragang Island in order to provide better headroom for large trucks the power supply was redirected into an underground route under the access road. Austberry drilling were appointed to install the 45m long 600 mm diameter bore and GFWAust were responsible for filling around the conduits with a non-shrink grout.
K2RQ
The duplication of rail lines between Kingsgrove and Revesby stations involves the construction of two new rail lines (each 6.5 km long) between the two stations, ten new rail bridges and a new overhead concourse and lift at Revesby station.
The project also included the provision of underground electricity cables at Morgan Street and Karne Street in Narwee. GFWAust were appointed to grout the bores around the conduits with a non-shrink grout.
Lindfield Rail Crossing
The works was carried out by Enerfised2U for AusGrid and GFWAust were appointed to grout the bores with the large volumes of high thermal rated grout.