Each layer of SPACE compacted
Each tree location marked with Greenwell
Paving base installed
Trees approximately 2400 high with 40 mm caliper
Installation in Southern section showing irrigation over SPACE trench
In 2007 a new Adelaide Interstate bus depot was built on the site of the old one in Franklin Street in the CBD.
As the site was heavily contaminated with material such as oil, diesel fuel, and heavy metals, a deep excavation was made in the north-west corner of the site and the contaminated soil was buried under a one metre cap of compacted clay.
This was unfortunate because the only landscaping permitted in the pick up and drop off area was the installation of small shrubs in raised boxes to avoid the breaching of the clay cap by tree roots. Given that any trees planted would struggle in such compacted clay in any case, Adelaide City Council set the architects Wood Baggot the task of finding solutions to the ban on trees. Without the shade and visual amenity provided by healthy tall trees the extensive paved area would have been a very hot and unwelcoming environment for travellers.
The solution was to place the paving on a 450mm deep layer of SPACE and pave directly over that. The SPACE was easily installed and compacted in 200 -300 mm lifts. The location of 29 advanced spotted gums (Corymbia maculata) was marked with Greenwells and sub irrigation lines installed to water each tree.
The trees quickly became established and are continuing to thrive without presenting any threat to the integrity of the pavement or roadway. The l use of SPACE by the Adelaide City Council was successfully employed in other similar projects in the CBD along North Terrace , the City West Campus of Uni SA, The Festival Centre, Hindmarsh Square and various commercial housing developments.