The Perfect solution for Urban Trees in Central Dandenong, Melbourne Australia

The Citygreen® modular StrataCell™ system became the choice of system to help revitalise the City of Dandenong, replacing previous systems too expensive to use.

In the heart of Melbourne’s growing southeast corridor is the city of Dandenong, the focus of the state government’s $290 million funded project.

The initiative “Revitalising Central Dandenong” aims to rejuvenate the city centre and create a fresh new future for the city. It is being delivered by the Victorian government through Places Victoria and in partnership with the City of Greater Dandenong.

Over 250 trees were planted as part of the project, which started in August 2010 and finished early this year. Lonsdale Street has been turned into one of Melbourne’s great boulevards with a green and pedestrian-friendly main street encompassing the city’s vibrant retail industry.

The Lonsdale street will “provide the setting for a mix of spaces to meet and socialise including cafés, restaurants, open spaces, gardens, civic spaces and community facilities”. It will have 251 Pin Oak trees, wider footpaths, various urban furniture, bicycle stands and other characteristics of an urban share space.

Landscape contractor Sugan Blanchard from Canteri Bros Constructions Pty Ltd was the project manager for RCD. He managed the Lonsdale street project, which was a major streetscape development of Lonsdale Street and Langhorne Street, costing around $30 million.

The original design used reinforced concrete slabs supported by steel screw piles over a continuous soil trench. At one point, Blanchard said the suspended slab supported on screw piles were becoming expensive due to poor ground conditions.

“The client appointed specialist consultants to investigate cost effective alternate system to piling due to projected cost increase,” Blanchard said.

After seeing the results of the projects in Auckland, New Zealand using the Stratacell system, the consultants were inspired to use the same for the Dandenong project.

“The consultants came up with Citygreen Stratacell system, and we did a cost analysis and provided cost and time saving to the project,” Blanchard said.

Stratacells are structural soil cells that come in modular units, which can then be assembled to form a skeletal matrix that supports pavement and traffic loads. This structural cell system features almost five times more available growing media compared to the traditional rock/soil method, therefore facilitating healthy root growth. Because of its high structural integrity, these matrices can be used beneath trafficked areas.

“The main cost saving was on the reduced thickness of the slab as it was designed as a slab on ground instead of suspended slab. We have never used this system before but found it to be easier to install and time efficient,” Blanchard added.

Major construction works were completed in April 2011 as a response to the community feedback received during the consultation period for the RCD’s 15 to 20 year Master Plan and Shared Vision. The Shared Vision includes plans to provide easy and safer pedestrian connections around the city, improved traffic situation and public transport, attractive public spaces for people to relax, high standards of environmental sustainability, more life on the streets and more green across the city centre.

Initially, Blanchard said the staff had to be monitored to ensure the correct installation of the Stratacell system. But with great support from Citygreen and the fact that the system is easy to install, everything went smoothly after the first installation.

Blanchard also found that the Stratacell system works well with water sensitive urban designs, “providing the structural strength to overlying pavement while allowing uncompacted growth media for trees”.

He says the Citygreen system is definitely a versatile system that they plan to use in future urban development projects.

Landscape architect Scott Adams, from Taylor Cullity Lethlean, also agrees with Blanchard. Aside from being the perfect fit for the project, Adams says they also picked Citygreen Stratacell system because it was made locally.

Although they couldn’t nominate a specific product for the project, Adams said they did specify for a plastic fill structure that could support the concrete so they can grow trees on the pavements. They found the Stratacell system to be the most effective system for the RCD.

“The system was successful in the result we wanted. We would be happy to approve the use of this product in the future,” Adams said.