Tasmania has embraced the Rocla MassBloc® earth retention system, with the first major installation on the island, a 5-metre high wall supporting earthworks at a new substation.
Hudson Civil, who manufactures the MassBloc®system under licence in Tasmania, supplied approximately 330 units for the retaining wall at a new electricity substation in Lindisfarne, on Hobart’s eastern shore.
Originally specified as a complex reinforced concrete structure, the wall was redesigned by Hudson Civil and GHD using MassBloc® units and offered as an economical alternative to civil construction contractor Hazell Brothers.
James Atkinson, of Hazell Bros, said that in terms of ease of installation, the MassBloc® wall was a cost-effective option.
“The original design had severe installation limitations,” James said, “including concrete curing time and potential weather delays.”
“The height of the structure, 4.5 or 5 metres, meant that steel reinforcing and no-fines concrete were required behind the wall,” he said. “Nevertheless, it was still much faster to erect and the installers could lay up to 60 blocks a day.”
The sloping site required cut and fill to create a platform for the new substation, with the two tapered walls meeting at the lowest point.
The works are part of a $130 million upgrade by Transend Networks to improve the power supply to southern Tasmania with two 220kV substations and a new 220kV transmission line.