Roy Earl Drive Civil Services

Lot 9501 Roy Earl Drive is a new commercial estate subdivision located in Cowaramup. Leeuwin Civil was contracted to perform earthworks; the installation of sewer and water reticulation; power; comms (Telstra); stormwater drainage; footpath and retaining wall construction. Works also consisted of a slip lane widening on Bussell Highway to Main Roads WA standards.

As works were undertaken on a low-lying site in reactive clay soils, this created a major challenge. Leeuwin Civil had to cut and fill the existing clay underneath the lots to a certain grade to allow the drainage to fall into the Main Roads road reserve V-drain. The cut clay was then covered with a minimum of 300mm of sand fill up to a maximum of 1m sand fill.

Each subdivision lot to be created required independent soil testing and geotechnical investigation to ensure the lot classification was achieved for the saleability of the lots. Latent conditions were also encountered in the slip land construction once the box out had been completed. Leeuwin Civil overcame this in conjunction with Main Roads by over excavation and backfilling with limestone. The road widening also required the construction of a new median island on the existing Bussell Highway along with new power and electrical lights running from the subdivision back to Cowaramup. All works were carried out under traffic management to Main Roads WA standards and specifications.

Scope of Works:

• earthworks in reactive clay soils;
• underground infrastructure installations including sewer and water reticulation;
• importation of sand fill;
• installation of stormwater drainage;
• underground Telstra power installation;
• traffic management;
• footpath construction and kerbing; and
• road widening and works.