Melbourne: Birrarung Marr Park

1 12 2009

Birrarung Marr, on the north bank of the Yarra River next to Federation Square, is Melbourne’s newest major park.

I was able to meet with Eamonn Fennessy from the City of Melbourne and Scott Adams, a landscape architect who worked on the project. They both provided me with great information on the park as well as other developments around the area.

The Yarra river is a major river system that comes from the mountains and winds its way down.  Melbourne went through a period of industrial trade and commerce backing up on the river, some noxious. The river was black and not something to be celebrated. Even up until the mid-80s, a lot of the river had massive at grade car parks and rail infrastructure. There is a history of the city turning its back on the river until the last 25 years. There was a major arterial road that ran up to the city where the park is now. In the mi 80’s, there was a big public campaign to reinstate the relationship between the city and the river and it has driven a lot of revitalization from Birrarung Marr to the new Docklands. The city is still evolving in its relationship to the water and will be changing in the next decade.

The park’s name comes from the language of the Wurundjeri people who originally inhabited this area, ‘Birrarung’ means ‘river of mists’ while ‘Marr’ refers to the side of the river.

Opened in 2002, Birrarung Marr provides a link between the Central Business District and Melbourne’s main sporting precinct and contributes to a continuous green belt of parkland around the city. It was the first park built by the city in over 100 years. Most of the other park were built in the Victorian era 100 years ago and had European composition and tradition. The goal at BM was to reflect the landscape an geology of Australia and celebrate its aboriginal roots.

Plantings of more than 200 young trees and hundreds of smaller native plants identify this contemporary park design as distinctly Australian. Hundreds of new trees and native plants enhance the park, particularly on the sides of the middle terrace. This includes a variety of hardy Australian natives, including an embankment of evergreen cycads, which means the park will continue to take shape in the years to come as they mature. Mature trees that formed part of the site before the park’s construction have been retained and 36 elms in Speakers’ Corner are listed on the Heritage Register.

The park is a great pedestrian space and event area. It creates a connection from Federation Square to the Sporting Complex. In 1996, the State and the City of Melbourne jointly sponsored an architectural design competition for Federation Square. The site for this project had been the subject of civic improvement for decades. The finished project now includes the new museum of Australian art, a base for film and media-related institutions, a mixture of retail facilities, a major civic plaza and various smaller public spaces, all built on decking over railways.

 

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Eamonn Fennessy is the Team Leader Parks Planning for the Design and Urban Environment for the City of Melbourne.

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Scott Adams was the Design Manager for Birrarung Marr for the City of Melbourne. He is currently working on a waterfront development in Auckland NZ which involves a couple of seawall edges. He is also doing another waterfront project in Geelong and is currently looking at a part of Melbourne’s dockland waterfront.





STOP #3: Melbourne

28 11 2009

After a brief side trip to scuba dive at the Great Barrier Reef in Cairns, I am now in Melbourne:

Melbourne is the capital city and most populous city of the State of Victoria, and the second most populous city in Australia. As of 2009, it had an approximate population of 4 million. The metropolitan area is located on a large natural bay known as Port Phillip. It extends from the CBD at the estuary of the Yarra River (which enters the bay at its northern-most point), along the south-eastern and south-western shorelines of Port Phillip, and extends into the hinterland. The CBD is located in the municipality known as the City of Melbourne.

Melbourne brings the focus back towards its waters with the new Birrarung Marr park located on the north bank of the Yarra river, adjacent to Federation Square. Heritage-listed elms and native flora are being brought right back into the city — something I believe can only be a good thing. I plan to discover how the introduction of this park has affected the surrounding built area.

I am meeting with Eamonn Fennessy from the City of Melbourne and Scott Adams, a local landscape architect.





Brisbane: Meeting with the Port of Brisbane

25 11 2009

I was able to meet with Brad Kitchen, the Manager of Environment for the Port of Brisbane Corporation, Scott McKinnon, Senior Environmental Coordinator and Peter Boyle, Manager of Reclamation and Land Development. They gave me an expansive tour of the site as well as showed me presentations that explained the Port expansion and the environmental studies they have done.

Brad took me to 2 other sites that show the incredible work the Port is doing in several sites around Brisbane to move the Port businesses to the mouth of the Brisbane River so that old Port sites may be opened for landscape, parks, and mixed use development.

Brad first took me to Northshore Riverside Park. This development used to be industrial concrete apron that housed Port buildings and utilities. It has now been transformed into a park and cafe as a benchmark for future development, which the Port hopes will include commercial and residential activation along the water’s edge:

 

 

 

 

 

 

 

 

 

We then drove to the Port of Brisbane, where all of their buildings are rated Green Star buildings, a similar ranking to LEED. Here is a map of where we were:

The Port of Brisbane is a fast growth port in Australia’s fastest growing city. Its challenge was to provide world class infrastructure to ensure capacity for trade growth well into the future. The Future Port’s Expansion Seawall Project: to build a rockwall to enable the reclamation of 230 hectares of land was a major undertaking. With a unique set of challenges:

– for the Port, the need to maintain business as usual during a time of record trade growth.

– for the engineers, constructing a seawall on soft marine clays up to 30 meters deep with unknown settlement factors.

– and for all stakeholders, the need to minimize environmental impacts on a site extending into Moreton Bay.

An alliance approach with the shared values of innovation and continuous improvement was chosen to meet these challenges. The Partners: Port of Brisbane Corporation, Leighton Contractors, Coffey Geosciences, WBM Oceanics, and Parsons Brinckerhoff. This gave them the opportunity to innovate and come up with very good solutions and they were thrilled with the outcome that came in under budget and ahead of time.

 

The project involved construction of a 4.6 kilometer rockwall to enclose an area that will be progressively filled with material from river dredging and then built upon to expand the Port and its wharfs. The seawall is a rock structure placed on top of layers of geofabric and sand. Made up of 1.3 million tons of rock, 375,000 square meters of geofabric, and around 420,000 cubic meters of sand, the seawall was constructed at depths ranging from 6 meters to less than a meter. They faced challenges in finding the correct rock and the correct sizes as well as the right cleanliness for the seawall. Instead of relying on trucks to deliver rock to the site, the alliance railed rock from a nearby unused quarry. This quarry was able to supply rock with little dust, which meant that the need to costly environmental management actions such as silt curtains or washing the rock were not needed. The clean rock met the alliance’s strict environmental concerns and cut costs and construction time. The team designed customized containers to transport the rocks by train to the Port of Brisbane. The special containers were then transferred to modified trucks and then taken to the site. This avoided the need for double handling or stockpiling the rock. Here is Brad speaking about the seawall:

Since building the rockwall in 2004, they have noted increased marine activity along the wall.  They recently engaged a consultant (WBM) to undertake an ecological assessment of this habitat. The aim of the study was to form a baseline condition (5 years since construction), allowing them to benchmark the performance of this structure against artificial reef structures in this region.  Results to date are very pleasing. Scott gave me an incredible presentation on how they have monitored the growth of flora and fauna along the seawall. Here is Scott speaking about the seawall:

Brad also took me to a site near the Port where they needed to divert a river and build a drain. Instead of simply building a concrete drain, they have made a new kind of drain. Using gabion boxes and tubing to let mangroves grow through, Scott came up with an environmental way to deal with the slopes of the drain while allowing for maximum development:

 

 

 

 

 

 

 

 

 

 

 

 

 

I was deeply impressed by the Port’s dedication and commitment to making their campus one open to the public and sensitive to a range of environmental issues. Their visitor’s centre, cafe, and overall campus caters to the education of what a Port should be: An incredible organization at the forefront of Port design.

They gave me an abundance of great info – I will upload more soon…





STOP #2 – Brisbane

24 11 2009

Brisbane is the state capital of the Australian state of Queensland and is the largest city in that state. With an estimated population of approximately 2 million, it is also the third most populous city in Australia.

The city is situated on the Brisbane River on a low-lying floodplain between Moreton Bay and the Great Dividing Range in southeastern Queensland. Brisbane is fast becoming a world city renowned for its culture, architecture and landscape. The metropolitan area is surrounded by many national parks, and contains many rivers, bays and inlets.

The Future Port Expansion (FPE) Seawall at the Fisherman Islands is one of the biggest marine-based projects undertaken in Queensland, catering for rapid commercial growth around Brisbane’s port area. The FPE seawall alliance has demonstrated that it is possible to deliver seawall upgrades and new infrastructure without sacrificing the delicate environment.

I intend to discern how this seawall has been planned and executed as well as how the current built environment is responding to it. I will be meeting with Brad Kitchen from the Port of Brisbane to discuss the ecological assessment of their Rockwall 5 years after its completion.





Sydney: the connection to the water

22 11 2009

Sydney is a great example of an industrial city that has transformed its image and waterfront to fit its commercial expansion. The waterfront is a destination catered to pedestrians and bustling with activity.

What is a successful urban waterfront? Of course, there are many other issues but these 3 represent the main issues a waterfront development should address:

– A clear and concise pedestrian connection to the water

– A commitment to environmental sustainability, whether it be through creating habitat in the water or through the landscape.

– A statement about the importance of education the present and future generations about the importance of a sustainable waterfront

After meeting with Peter Nowland and Rafael Chemke from the Sydney Harbour Foreshore Authority, they showed me some important spots along the harbour that I should visit. Here are a couple:

White Bay Seawall

Parts of an old vertical concrete seawall at White Bay had become unsafe and were due to be demolished and rebuilt.

Sydney Ports Corporation considered several different designs, most of which consisted of an inclined rubble-bank of some description. The design that was chosen to replace the old seawall is a stepped wall made of large rough-cut sandstone blocks.

The new stepped design means that the seawall has horizontal surfaces, approximately 0.5m wide and vertical surfaces, approximately 0.3m high, at various heights on the shore – a considerable change over the previous vertical concrete seawall. It also has similar composition to local natural rocky shores. The steps incorporate horizontal surfaces, which are a common feature of most rocky shores around Sydney, but are usually lacking on seawalls. This will increase the intertidal area as well as allowing for small rock-pools.

Picture 018 Glebe Point Park is a good example of redeveloping the foreshore with a sandstone seawall, access points to the water, and a pedestrian/biking trail along the edge. It is a mixture of seawall and natural shoreline and re-established mangroves.

 

 

Picture 169

Ballast Point was an old industrial refinery. As a contaminated industrial site, it has now been rebuilt as a public park with heritage fabric and historical story telling. They also renovated the existing sandstone seawall. This park portrays 20-25 years of landscape architecture evolution by providing a modern park using old materials.

 

Picture 165Picture 145 

 

Picture 102Peacock Point: In the 70s, the Sydney School of Architecture heavily influenced the landscape architecture language of the area. They believed that local bush should be reintroduced and the old industrial language of heavy timbers and bridge girders preserved. This park was the first to incorporate this style through bollards, picnic shelters, heavy timber stairs and benches.

 

 

I will be going to others on my way home to Seattle. For now, off to Brisbane….





Sydney: Meeting with Ashraf Doureihi

20 11 2009

I met with Ashraf Doureihi from the North Sydney Council, which is the Council that managed the McMahons Point seawall.

Most seawalls around the harbour are 100 year old heritage sandstone walls. They have stood the test of time but over the years and with increased wave action, a lot of the material held back by the seawall begins to siphon out through the joints.

A typical scenario for a Sydney sandstone seawall will begin showing signs of fill failure by sunken holes being present at the pedestrian level. The Councils use a pre-emptive program to save walls before they collapse, avoiding having to rebuild them from scratch. They have been using the grout penetration process for about 17 years now, which was an in house design. Grout penetration consists of drilling 100 millimeter hole casings 1 meter behind the seawall all the way down to the foundation every 3 meter spacing. They then pump grout underneath using a tremmie and a special mix that has been adjusted through trial and error.

The grout penetration then goes through 3 stages:

1 – Build a concrete toe grout at the foot of the existing seawall at .25 meter height

2- Pump/inject grout into all voids in the foundation

3- Raise tremmie to fill all holes along length.

The average cost of rebuilding a failed seawall is around $12,000-18,000 per linear meter. The grout penetration greatly reduces the cost to around $3,000-6,000 per linear meter and preventing any injury to pedestrians. There is a very low 5% rate of failure in grout penetrated seawalls.

At McMahons point, sections of the seawall had collapsed and the sea bed floor was extremely weak. This was a unique case that needed special attention since the sea floor had no bearing capacity and could not be knocked down and rebuilt. The North Sydney Council installed steel I-beams by hammering them 8 meters deep on average until they hit bedrock. They were tied back 10 meters to concrete anchors installed underground every 5 meters. Then, L-shaped precast concrete panels were attached to the steel beams. Sandstone blocks were then laid on the bottom section of the L and built vertically. Several blocks were left out for environmental purposes as they had no structural significance. They also incorporated a rock armor along the bottom of the seawall to protect against an abundance of wave action.

This 150 meter section of seawall cost around 2 million dollars, or $20,000/linear meter. This cost was justified because of the prominence of this spot in the Sydney Harbour. It had to be built vertically as it is prime real estate and could not take up pedestrian space with a sloped seawall. The site had to closed down for 3 years to raise funds and was built in 4 months, completed in 2006. This project shows a great 12 years relationship with the University of Sydney and the biological strength of seawalls. The site used to have zero marine life and has now blossomed with habitat. It is a great example of an urban vertical seawall that provides biodiversity.

The success of the project hinged on a great contractor and project manager that overcame hurdles easily. One hurdle included encountering a large sewer pipe in the way of the tie backs. This included convincing the Sydney Water Company of the benefits of this seawall/

This project could definitely be adjusted to fit the Alaskan Way Seawall. Ashraf explained that the sea wall depth bears no significance on the project, as the structural bearing relies completely on the steel I-beams, which could be drilled to any depth needed.

Ashraf sketched some images of the different seawall options and said he could provide me with the engineering drawings for the McMahons seawall. Once I return to the States, I will scan and upload said images.

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Ashraf Doureihi is the Design & Investigations Engineer for the North Sydney Council.





Sydney: Meeting with John Heptonstall

19 11 2009

Located on the northern shores of Sydney Harbour, Mosman offers a rich cultural life amidst beautiful bush land surrounds. Mosman Council plans for building and development, maintains parks, beaches and sporting facilities, provides services for children, youth and seniors and runs cultural activities, a library and an art gallery.

Many of Mosman’s seawalls are nearly a century old and many are heritage listed. Some, including the walls at Mosman Bay, Quakers Hat Bay and the Spit are showing the effects of exposure to the elements, with collapsed and damaged sections, fallen sandstone blocks and subsidence behind the wall.

Ecological engineering Mosman’s foreshores

Council has developed a proposal for seawall works at Spit West, Spit East, Parriwi Point and Musgrave Street. Integrated with the seawall works in Spit East and Spit West is a proposed upgrade of access along the foreshore.

Seawall works will include rehabilitation, maintenance, upgrading walls and the establishment of new habitats for marine flora and fauna.

The proposal for improved access along the foreshore in Spit East will include improvements to the boat ramp, a new bicycle path, pedestrian path, bus bay and shared zone. In Spit West the proposed access improvements include a shared path for bicycles and pedestrians linking Pearl Bay Avenue to the Spit Bridge and mobility access from the car park to the foreshore.

I met with John and he took me to the Pearl Bay/Spit seawall which is about to the opened.

At Spit Bay, before there was a plain faced concrete seawall that covered the embankment. Besides some oysters that were growing along the bottom, there was no habitat to speak of. Also, the concrete was cracking in several spots and lifting out. Where they have implemented the new rock armory, an abundance of life has blossomed and provided a great comparison of an environment that provides habitat versus one that just has a concrete wall.

They used a rock armory to provide a barrier to tidal waves and structural stability at the base of the seawall where it is sliding out. This method of saving the seawall without having to rebuild it cost about 1/5 of the cost of rebuilding the seawall – this is quite significant across 800 meters of seawall. They implemented a rock armory to protect from tidal action and varied the placement and size of stone related to where the wave action comes from and its variance in strength. They scraped loose material at the bottom, placed geotextile and placed the stones – its slope is at one vertical to one and half horizontal. The rocks have been designed by coastal engineers. This provides stability at the bottom of the aging seawall and stops the seawall from sliding down.

They got the rocks in a quarry north of Sydney and they had to go through stringent testing to check the stability of the sandstone rocks. One of the major issues with seawall rocks is that they breakdown with the attack of sulfites and they had to test they could withstand the constant wetting and drying of being at a seawall.

The rocks provide shelter for smaller fish and it creates a breeding ground for habitat. There is quite a lot of sea life. The only minor problem they are getting is some litter issues that washes in from the harbour, which can be remedied by regular clean up maintenance.

On the ground, they implemented a bike trail and a pedestrian trail as well as planting that will eventually grow and become quite dense to act as a handrail for bicyclists and pedestrians. They also augmented a natural beach and put more sand in to create a high tide beach. At low tide you have a recreational beach area and it also creates habitat.

They worked with the Department of Energy and Climate Change as well as the University of Sydney – they have taken ideas from different sites to diversify the habitat and create a recreational area.

Another habitat they created was a salt marsh area where a section in inundated at high tide and allows the salt marsh to live within the correct habitat. They are providing it as an educational tool to show how seawalls should look like with signage and tours:

They also built a large tide pool that will flood at high tide and provide a shallow water habitat at low tide:

We also visited Quakers Hat Bay, where they were looking to create habitat for oysters and small fish. They’d like to study what actually has grown and lives there since it was built. They have worked with the University of Sydney about their research and gotten a lot of ideas of what can be done in each situation:

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John Heptonstall is a Contract Engineer for the Mosman Council. He is the engineer principally involved in the project management of the design and construction of the Mosman seawalls.

Mosman’s walls have been designed and built in collaboration with Sydney University’s Centre for Environmental Impact in Coastal Cities (EICC). Also the state government’s Department of Environment and Climate Change has been involved with advice and funding as well as coordinating knowledge around the Sydney region for ecological engineering works.