THE ROLE OF HERITAGE STRUCTURAL ENGINEERING AND WHY IT IS IMPORTANT FOR FUTURE GENERATIONS

Transcription

1 THE ROLE OF HERITAGE STRUCTURAL ENGINEERING AND WHY IT IS IMPORTANT FOR FUTURE GENERATIONS John Woodside, FIEAust, F.ASCE, FICE, FIStrucE, NER, RPEQ, Principal, J Woodside Consulting, SA Ian Maitland OAM, FIEAust, NER, CPEng Maitland Heritage Engineering, WA

2 WHY HERITAGE IS IMPORTANT Since our time began, humans have been making things. Each time we make something, we remember what we did last time. There are hiccups along the way, but over time, we improve on what we did last time. This course of continuous improvement is what the public expect from engineers, and it is accelerating at an unprecedented rate. Places of heritage significance enrich peoples lives, often providing a deep and inspirational sense of connection to community and landscape, to the past and lived experiences. They are historical records that are significant expressions of Australian identity and experience. Such places reflect the diversity of our communities, telling us about who we are and the past that has formed us and the Australian landscape.

3 Australian Heritage

4 The Lachlan River NSW in flood with the Overland country to the north where the Clancy brothers drove sheep to Qld

5 WHY HERITAGE IS IMPORTANT Our heritage defines our identity, achievements, skills and demonstrates our ability to overcome adversity. Modern society is consumer driven. We acquire something new and discard the old. Our engineering heritage has suffered a similar fate. Beautiful old buildings are torn down to make way for new ones. Magnificent old timber buildings, mining structures and bridges are deteriorating rapidly. We are losing our history. All of us have a role in preserving our heritage, whether it be manmade or natural.

6 WHY HERITAGE IS IMPORTANT -St Georges Cathedral, Perth

7 WHY HERITAGE IS IMPORTANT - Palm House Adelaide and Morgan Wharf, Morgan SA

8 WHY HERITAGE IS IMPORTANT - Adelaide Oval, Melrose and Flinders Ranges, SA

9 WHY HERITAGE IS IMPORTANT lift bridge near Carathool and Emerson tractor, Griffith, NSW

10 WHY HERITAGE IS IMPORTANT - Gulflander, Normanton Qld, concrete bridge, Castlemaine, Vic and concrete water tower, Leeton, NSW

11 WHY HERITAGE IS IMPORTANT Bygoo Station, NSW

12 FUTURE USE Australia has a wealth of underutilised heritage buildings and other structures in prime locations. Not all buildings or structures may deserve preservation and none have an infinite life There are numerous buildings and structures that should be preserved with foresight and some effort. In the future, we do not believe society can continue to demolish every building just for the sake of a new marvellous building to replace it. We need to look at existing buildings and ask how can we reuse them as part of a redevelopment process where practicable and sustainable.

13 FUTURE USE Our forebears were very good at repairing things and making things last. That trait has not been passed on to the younger generation, many who think that anything is old, is past it. It is very important that we educate the younger structural engineer in understanding that it is perfectly legitimate to repair, upgrade and reuse a building or structure, if practical to do so. We have a professional obligation to advise clients of this possibility. Also from an environmental point of view, the reuse of an existing building or structure is a far more sustainable result than a new building or structure and will reduce the carbon footprint.

14 WHAT IS CULTURAL HERITAGE? Cultural heritage is the legacy of physical artefacts and intangible attributes that are inherited from past generations, maintained in the present and bestowed for the benefit of future generations. Tangible culture such as buildings, books, works of art and engineering infrastructure Intangible cultures such as traditions, language, and knowledge Natural heritage such as culturally significant landscapes. Cultural heritage is all around us. Significance defines the importance we assign to heritage places or items. Cultural significance means aesthetic, historic, scientific, social or spiritual value for the past, present or future generations. A built item does not necessarily have to be old to be classed as culturally significant. This concept of heritage significance forms the basis of the Burra Charter, first adopted in 1979 in the South Australian country town of Burra.

15 BURRA, SA

16 ROLES OF STRUCTURAL ENGINEERS IN HERITAGE PROJECTS There are numerous ways in which a structural engineer can participate in heritage work, including: Assessment of structural adequacy Assessment of cultural heritage significance Risk assessment Heritage impact statements Condition assessment Input into conservation plans Proposals and documentation of conservation work Contract administration of conservation works Advocates for conservation

17 ROLES OF STRUCTURAL ENGINEERS IN HERITAGE PROJECTS For buildings and civil engineering infrastructure, structural engineers will often be asked to advise on the conservation of work other than the usual structural materials steel, concrete, timber and masonry. This has come about because engineers are educated in properties of materials. This understanding of materials of construction and how they behave increases through an engineer s career.

18 WHAT DOES A HERITAGE STRUCTURAL ENGINEER NEEDS TO KNOW? There are no courses in heritage engineering, in Australia, and few worldwide. Most engineers practicing in heritage are structural engineers. Our estimate is that there are only about structural engineers in the country whose principal activity is heritage related work. There are many more who undertake the occasional heritage project, or projects with a heritage component. Usually this small group of full time structural engineers, no more than a handful in each state, who are mature age engineers, with a solid background in design of structures and materials, but also in the assessment of structural failures, and devising solutions for remediation and repairs. Along the way, they have learned about the Burra Charter and how the heritage community operates. Also typically, these engineers will have a strong interest and commitment in the conservation of our environment. Most of these engineers have learned on the job and over the years have established a sound track record in heritage work.

19 WHAT A HERITAGE STRUCTURAL ENGINEER NEEDS TO KNOW BURRA CHARTER

20 THE BURRA CHARTER Places of cultural significance should be conserved. Conservation is based on respect for the existing fabric and use. Adopt a cautious approach change as much as is necessary, but as little as possible. Make use of all the knowledge, skills and disciplines which can contribute to the study and care of the place. Change may be necessary to retain the cultural significance but is undesirable where it reduces significance. Changes which reduce cultural significance should be reversible. Demolition of significant fabric is generally not acceptable. Maintenance is fundamental to conservation. New work such as additions may be acceptable when it respects the cultural significance. New work should be readily identifiable as such, and have minimal impact on the cultural significance of a place.

21 HERITAGE ENGINEERING A heritage structural engineer needs to have good understanding and awareness of: History of construction materials and techniques since European settlement. The structure and content of conservation plan. Traditional forms of construction. Early methods of structural design. The use and misuse of past and current Australian Codes and Standards. The roles of various participants in the heritage community,.

22 HERITAGE ENGINEERING The properties of older materials such as cast iron, wrought iron and early concrete and proprietary reinforcing systems for concrete as well as architectural materials. Causes and processes of decay. Conservation techniques. Conservation products use and misuse. Regional differences. Non-destructive methods of testing. The effects of rising damp.

23 HERITAGE ENGINEERING Problems of past construction techniques and products, which have not passed the test of time. Examples include: Overstressed and the deflections of long span timber structures, such as in churches. The use of blended cement in concrete, as used in Western Australia in the 1970s. Reinforcement in concrete with insufficient cover. Eroding bricks due to the low temperature of the firing. Expansion of brickwork due to brick growth. Deflection and elastic and creep shortening of concrete structures.

24 LOADS Just because an existing building or structure does not comply with current Australian Standards, does not mean that it is necessarily unsafe or likely to fail. Remember the 2 day RULE It is also important to remember that floor loads in the current Standards are almost never achieved in real life. Sometimes buildings and structures are over designed and often load testing will show that they will carry substantially more load than that resulting from calculations. In a similar manner, structures should not be expected to comply with current wind or earthquake standards.

25 LOAD TESTING

26 RESOURCES What resources are available to the heritage structural engineer? With the Internet and the digitising of much information, there is a wide range of material accessible. If the original drawings are available, this will significantly help. Engineers Australia has a number of practice notes and guidelines, The involvement of a historian or heritage architect in a project, will provide important background giving clients and team members sound understanding of the heritage significance of the project.

27 RESOURCES What other resources are available to the heritage structural engineer? NLA Trove. ICOMOS. The Institution of Civil Engineers (ICE) have excellent resources, the Institution of Structural Engineers (IStructE) in the UK.

28 CONCLUSION The structural engineer may have to engage the services of others to assist them This process of research requires much perseverance and time. This needs to be allowed for in the conservation and design process and the professional fees quoted for this work. In situ testing and trial repairs might also be required to prove the viability of options to be chosen. It is also important to have a contractor experienced in this type of work. Sometimes for a project, a cost plus basis or a schedule of rates contract provides the most economical solution.

29 Specialists

30 CONCLUSION The working life of a heritage structural engineer is varied, interesting and very fulfilling. It is also often very challenging. To arrive at a site to find a dilapidated structure, in a seemingly ruinous state, one can be overwhelmed with a feeling of where to start? The structure and its problems are often hidden from view. There may be numerous options for conservation and selecting the right one with minimal physical intrusion, can be an art form which requires many skills engineering, lateral thinking, forensic, research, material behaviour and knowledge of conservation materials and costs.

31 CONCLUSION Engineering Heritage Australia intends to develop a full day course in Structural Heritage Engineering initially in WA and SA for practicing engineers. It will cover the following matters:- Introduction to the World of Heritage Traditional Forms of Construction Conservation Principles The Burra Charter Awareness & Knowledge Materials Physical actions Failures and decay Remediation Professional Practice matters Project examples What do you think of that imitative???