How do we lead our cities, communities and government towards designing and building the important sustainable infrastructure of the future? Professor Keith Crews - 30th November 2012 Use the hashtag #utspeaks to discuss this lecture on Twitter. UTSpeaks is an annual free public lecture series presented by UTS experts discussing a range of important issues confronting contemporary Australia.

1. Speaks: Our fragile cities (part one)
essor Keith Crews – 30 November 2011

2. Our Fragile Cities ……
Sustainability of Infrastructure
Keith Crews
Professor of Structural Engineering
Faculty of Engineering & Information Technology
Centre for Built Infrastructure Research
University of Technology Sydney
2

3. Overview
• Sustainability & Infrastructure
– An Engineer’s perspective
• Current Challenges
• Identifying Threats and
Managing Risks
• New Developments and
Opportunities
3

4. Sustainability
• Broadly, is the ability to maintain a certain
process or state, usually with respect to
biological or human systems
• Human sustainability has become increasingly
associated with the integration of economic,
social and environmental spheres
• Involves “meeting the needs of the present
without compromising the ability of future
generations to meet their own needs”
World Commission on Environment and Development (Brundtland Commission) – Report to UNGA 1987
4

5. Sustainability requires
a radical shift in thinking
Radical transformation of the
infrastructure that supports life on the
planet is needed if we are to attain a
sustainable future
(from Peter Head - Brunel Lecture 2009)
5

6. Evolution of the Ages
• Stone Age
• Industrial Age
• Information Age
• Ecological Age
6

7. (CO2 – 80%)
+ 1.44 gha / Capita
Ecological Footprint + HDI Increase
Human Development
Index
= 2050 Ecological Age
(from Peter Head - Brunel Lecture 2009)
7

8. HDI is a comparative measure of life expectancy, literacy,
education and standards of living for countries world wide
Human Development Index
8
(Peter Bowtell – ARUP)

9. Our Shrinking Earth
Greater Sydney - 6.18
1900 1950 1987 2005 2030 2050
7.91 5.15 2.60 2.02 1.69 1.44
Hectares of Land Per Capita
(from Peter Head - Brunel Lecture 2009
& NSW State of the Environment report 2006)
9

10. Sustainability & Economics
• Since Industrial Revolution
most Economic systems
are based on growth
• Growth = Prosperity
• Growth = Consume
• Now being confronted:
– Limits to growth
– Limits to resources
– Limits to consumption Source: NOAH / NASA
– Limits to environment 10

11. Energy Consumption
11
(Peter Bowtell – ARUP)

12. The CO2 footprint of transport
Sydney
(from Peter Head - Brunel Lecture 2009; 12
Quoted from Kenworthy - 2003)

13. Getting the Balance Right
• Sustainability: improving the quality of human
life while living within the carrying capacity of
supporting eco-systems
• More recently “Triple Bottom line” approach:
– commercially viable development
– enhance community wellbeing
– environmental renewability and
conservation of resources
• Objective of balancing these is “Sustainability”
13

14. Triple Bottom Line Philosophy
Social
bearable equitable
sustainable
Environment Economic
Balancing the viable
spheres of influence
Adams, W.M. (2006) "The Future of Sustainability: Re-thinking Environment and Development in the Twenty-first Century”

15. Sustainability and Infrastructure
• Economic growth understood
as New = Good
• Political Drivers
– New projects = success
– No votes in maintenance
• Educational Drivers
– Engineers trained to design
new, not sustain existing
• Decisions based on traditional
economic models, rather than
sustainability principles 15

16. Infrastructure Challenges
• “Infrastructure Australia” an excellent initiative
– Highlighted problems with planning
– Prioritisation and best value / national interest
– Aims to improve decision making processes
• However, the focus still appears to be on
“new” projects, rather than how we can
improve / maintain existing infrastructure
• Need for a change in mind-set and new
economic / decision making models if we are
to develop sustainable practices
16

17. Infrastructure Challenges
• Declining state of existing infrastructure is
evidenced by the Australian Report Cards
(IEAust & GHD)
– civil infrastructure is barely adequate or poor
– similar situation in US (refer Civil Engineers Aust - Feb 2009)
– e.g: 1 in 4 bridges either deficient or obsolete
• Private investment focuses on new projects
rather than maintaining existing infrastructure
– we actually need to get the mix right for BOTH!
• The Great Challenge of “Aging Infrastructure”
17
Priority: “Restore and Improve Urban Infrastructure” Nat. Academy of Eng. (July 2008)

18. IEAust Score Sheet – NSW 2010
18
(IEAust Infrastructure Report Card NSW 2010)

19. IEAust Score Sheet – NSW 2010
Key Recommendations:
• long-term infrastructure vision and plan
• greater attention to managing demand for
infrastructure services, rather than relying on
building new infrastructure to meet demand
• factor in the impact of climate change
• cooperation and collaboration between all
levels of government and business
• develop innovative funding models to maintain
and provide the required infrastructure
(IEAust Infrastructure Report Card NSW 2010) 19

20. Government Challenges
Funding tensions:
Maintain existing?
Upgrade / improve existing? 20
Build new?

21. Government Challenges
Funding tensions:
Maintain existing?
Upgrade / improve existing?
Build new? 21

22. Need for a change in mind-set
• OECD: sustainable infrastructure (structures)
requires 3% of the asset replacement value be
budgeted each year for maintenance (on average)
OECD Road Transport Research – Bridges (1992) / OUTLOOK 2000 (1999)
• Obviously this varies with age and use – new
assets would require less, older ones more
• Expenditure in Australia varies between less than
0.5% and 1.5% depending on the asset owner
(ave. for State Governments approx 1.2%; less in LG)
• This lack of adequate funding creates a cycle of
obsolescence
22

23. Degradation of Infrastructure
Degradation is caused by one or more of:
• “Normal” wear and tear
• Biological / Chemical / Environmental hazards
• Increased frequency of use (e.g. more traffic / demand)
• Increased magnitude / severity of “load”
– e.g. increasing axle loads from 8t to10t
increases the damage potential by 145%
– 10% increase every 10yrs
– Extreme natural events
– Climate change
23
ATSE Report “Assessment of Impact of
Climate Change on Australia’s Infrastructure” (2008)

24. Infrastructure Degradation
Degradation increases with failure to:
• Detail / construct for
durability
• Resource adequately
• Correctly identify
damage
• Understand its impact
• Intervene effectively
– Maintenance
– Repairs Source: Aboura et al – UTS / RTA (2008)
– Strengthen / Optimise 24

25. Some Examples of the
Challenges facing our cities
25

26. I-35W Mississippi River Bridge
• An eight-lane, steel truss arch bridge that
carried I-35W across the Mississippi River in
Minneapolis, Minnesota
• During the evening rush hour on August 1,
2007, it suddenly collapsed, killing 13 people
and injuring 145
• The bridge was Minnesota's fifth busiest
carrying 140,000 vehicles daily
• Opened to traffic in 1967, inspected annually
by Minnesota DOT, but not in 2007
26

27. 27
(NTSB photo)

28. What caused failure?
• Investigation by the National Transportation
Safety Board & FHWA research centre
• Jan 15, 2008, the NTSB announced they had
determined that the bridge's design specified
steel gusset plates that were undersized and
inadequate to support the intended load of the
bridge which had increased over time
• Nov 13, 2008, the NTSB released the final
findings of its investigation
28

29. Localised plate buckling
Photos - NTSB
29

30. What caused failure?
• The primary causes were:
– under-sized gusset plates for modern loads
– additional load from 51 mm of concrete (road
surface) increasing the dead load by 20%.
– extraordinary weight of construction equipment
and materials (262 t) on the bridge just above
its weakest point at the time of the collapse.
– inadequate inspection procedures.
– corrosion was not the significant factor, but it
had contributed to some weakening & cracks.
30

31. Proactive Asset Management
- Lessons Learnt
Understanding the condition of
the asset needs investment and
involves:
• Developing effective assessment
systems for quantifying safe
capacity / acceptable performance
• Identifying where the greatest
needs / risks are located
• Using this information to develop
and maintain an “information
system” that permits strategic &
cost effective interventions
• Essential for sustainable 31
management of infrastructure

32. Extreme Loading Events
Urban Flooding
32
Photos – Courier Mail / AFP

33. Extreme Loading Events
Cyclonic Winds
33
Photos – Paul Crock AFP

34. Extreme Loading Events
Earthquakes
34
Photos – Andy Buchanan

35. Sustaining Infrastructure
• The issue of aging infrastructure applies to all
materials and all types of structures / assets
• The reality is that we cant afford to replace
every piece of infrastructure
• Engineers have a professional and social
responsibility to maintain the operational
effectiveness and safety of infrastructure
• Both a challenge and an opportunity!
• Illustrate - short focus on timber structures
35

36. Example:
Timber Structures in Australia
• Historic applications
• Current applications
• Development of “tools”
that enable sustainable
practices
– damage detection
– risk assessment
– strategic maintenance
– repair & rehabilitation
36

37. Timber has been an
essential and integral
part of rural Australia’s
buildings and
infrastructure since early
European settlement

38. Structures such as these have
been “out of sight, out of mind”
Yet, despite the fact they are
often not well maintained
Many are still performing well
After 150+ years!

39. Similarly with bridges –
an essential, but under
valued part of our rural
infrastructure

40. Multi-storey timber
warehouses were common
in the 1800’s - many have
been recycled into offices

41. However, lack of
understanding
about
detailing, maintenan
ce and durability
issues can lead to
performance
problems

42. Resulting in the
need for expensive
repairs!

43. Case Study:
Sustaining Timber Bridges
• A main focus of R&D at
UTS since 1990
• Collaborative with RTA,
Industry, Local and Federal
Governments
• Approx $5m of R&D
projects
• Development of new
technologies:
– risk ID / assessment
– repair & rehabilitation 43

44. Timber Bridges - Context
• Approx 40,000+ bridges in Australia
• Approx. 27,000 are aging timber bridges
– most are girder / corbel (spans 8-10m)
– some truss bridges (spanning up to 36m)
• Essential part of our transport infrastructure
– mainly in rural areas / Local Government
– most 70+ years old
– designed for 14 to 18t
– now carrying 44t plus!
• Asset value in excess of $25B
• An important part of our history
with social & cultural significance
44

45. Special Challenges with
Heritage Structures
• Heritage Legislation
means that many old
bridges must be kept
operational
• Tension between
maintaining hist. integrity
(size of members) and
safety for current loads
• Significant R&D projects,
consulting and training
• Development of new
structural systems, design
& detailing methods 45

46. Addressing the “guess work” in strength
assessment of bridges….
One of the biggest
problems has to do with
the assumptions we make
and conclusions we draw
when we assess / model
the bridge structure……
46

47. Uncertainties & Assumptions
• Reliable assessment requires
accurate information about:
– Integrity of member sections
(decay / corrosion / spalling)
– Load history and damage
– Structural interactions
– Material properties
(variability and aging effects)
• Errors can be significant!
• Overly conservative decisions also
can be costly!
47

48. How safe is safe?
48

49. Tools that Facilitate
Sustainable Practices
to manage
Infrastructure assets

50. New Technologies for
Damage Detection
• Significant R&D on NDE technologies for
determining the location and extent of “damage”
• The concept of “health monitoring”
• Emerging Technologies (most promising):
– Dynamic / Modal Analysis
– Radiography and GPR
– Stress Wave techniques
– Acoustic Emission
• Potential for a “quantum leap” in assessing the
condition of existing structures
50

51. Dynamic / Modal Analysis
• New method developed by UTS in
partnership with IPWEA / RTA
• Provide good “global” indication of
safe response of superstructure
• Quick to perform and cost
effective
• Provides accurate information
about global behaviour of beam
structures (timber, conc & steel)
51

52. Dynamic / Modal Analysis
• Next generation identifies
location and size of damage
(voids / loss of member integrity)
• Development of neural networks
that enable the system to “learn”
• Linked with probabilistic strength
models derived from testing
52

53. Ground Penetrating Radar
• Uses electromagnetic
waves to generate an
image of internal features
• Ideal for investigating
objects with low
conductivity such as
masonry, concrete and
timber
Source: W.Muller – QDMR (2008) 53

54. Ground Penetrating Radar
• Recent developments can create
3D images
• Can be used effectively with other
NDE (e.g. thermal imaging)
54
Source: L. Binda – TU Milano (2008)

55. Ultrasonic Tomography
• Ultrasonic pulse velocity (UPV)
used to create 2D and 3D images
of internal voiding
• Data is analyzed in terms of
propagation velocities and arrival
of the transmitted ultrasonic pulse
Source: De La Haza et al - SFR (2008) 55

56. Acoustic Emission
• AE signals can identify
micro-cracking mechanisms
in reinforced concrete
• Applied to corrosion-induced
cracks due to expansion of
corrosion products
• Potentially effective for
identifying / quantifying
damage accumulation
Estimate of crack depth Image of water filled crack
56
Source: Ohtsu et al - SFR (2008)

57. Implementation Challenges
• Translating R&D into practice
• Training professionals to
interpret and apply the results
• What is the effect of damage
on structural performance?
• Is it still safe?
• What needs to be done?
• How soon?
Client: How do I fix it?
57

58. Key Steps to Sustaining
Infrastructure for our Cities
What have we learnt from all this?
• Understand the asset, what is does, how it is
performing and what is required to keep it safe
• Rate it’s value using “triple bottom line” criteria
• Accurately assess and quantify it’s condition
• Maintain and plan strategic interventions that
repair, rehabilitate or upgrade
• Develop tools and techniques for “sustaining”
rather than “replacing”
• Fund accordingly
58

59. Aging Infrastructure makes our
cities vulnerable and fragile
• Our cities are more than
buildings and physical
infrastructure, yet they are
totally dependent upon it
• Infrastructure is often
hidden; a skeleton that
provides a framework for
the city eco-system
• Design and operation of
our cities is a critical
challenge to humanity in
the 21st century
59

60. Urban – Rural crossover
Half the worlds population live in cities ...
which are responsible for nearly 75% of
the world’s greenhouse gas emissions
60
(from Peter Head - Brunel Lecture 2009)

61. The Urban Challenges
• Transport
• Existing Buildings
• Waste Management
• Water
• Energy Supply
• Outdoor Lighting
• Planning &Urban Land Use
• Food & Urban Agriculture
• ICT
• Finance & Economy
• Climate Adaptation
http://www.arup.com/Publications/Climate_Action_in_Megacities.aspx 61
(source: Peter Bowtell ARUP - 2011)

62. Buildings account for:
• 38% total energy use
• 65% electricity consumption
• 30% CO2 emissions
62
(from Peter Head - Brunel Lecture 2009)

63. A Paradigm Shift
Buildings are critical, renewability is essential:
– Materials
– Energy
– Total Life Cycle
63
(from Peter Head - Brunel Lecture 2009)

64. Potential of Timber in Buildings
• Timber has a role to play in
infrastructure for cities
• Why?
– Structurally efficient & reliable
– Low process energy
– Efficient carbon store
– Recyclable & Sustainable
– Relative ease of de-construction
– Renewable - we can grow more
• Overview existing uses
• New timber technologies 64

65. Normal “current” uses
ALL LOADS CARRIED BY TIMBER!

67. Source: B Hutchings - TimberBuilt P/L (2008)

68. Source: B Hutchings - TimberBuilt P/L (2008)

71. New Building Applications –
Drivers for O/S developments
• “Green building” a is strong driver for use of timber
overseas in terms of carbon store, process and
operating energies and renewability
• Shift from individual dwellings to multi-functional
precincts (multi-storey commercial & residential)
• New products with inherent sustainability (LCA)
• Prefabricated Floor, Wall & Roof systems with
significant benefits for construction and de-
construction / recycling
71

72. New Developments in Europe
7 storey building - Berlin
72

73. New Developments in Europe
M-M Kaufmann Glulam & CLT
73

74. New Developments in Europe
4 storey building - Munich
74

75. New Developments in Europe
KLH - Austria
75

76. New Developments in Europe
Up to 6 storeys
– Switzerland
76

77. New Developments in Europe
9 storey building - London
77

78. New Developments Overseas
Up to 6 storeys
– Canada
78

79. Prototype Buildings
NMIT – Nelson NZ
79
Aurecon - Engineers, ISJ - Architects

80. Prototype Buildings
NMIT – Nelson NZ
Winner of the Institution of Structural Engineers UK’s
Structural Awards 2011 in the health & education category
80

81. Sustainable Buildings
• Timber has a role to play as a
sustainable material for
buildings in the Ecological Age
• Designing for “whole of life”
value & worth
• Understanding sustainability
processes
• Detailing & const. for durability
• Creative use of new products
and processes
81

82. Conclusions:
Sustainable Infrastructure
• Significant challenges facing Design Professionals,
Planners and Government
• Urgent need to educate existing & future decision
makers:
– Triple Bottom Line “sustainability” principles
– Design of new structures incorporating “renewable” mat’s
– Assessment, protection / enhancement of existing
• Need for us to provide leadership in the community
– Understanding and communicating the need for change
– Lobbying for appropriate resources
– Using our skills & new technologies to create and
implement sustainable practices 82

83. Conclusions:
Sustainable Infrastructure
• Aging infrastructure is a risk
to our Cities that must be
recognised and addressed
• How we manage existing
and create new
infrastructure must be
informed by an ethos that is
committed to the concept of
sustainable precincts
83

84. New thinking is critical for the Economic, Environmental and Social
aspects of Australia’s Infrastructure and Cities it supports, to become
truly Sustainable. Creative leadership and the multidisciplinary skills of
Designers, Planners & Decision makers are essential for this to occur.
thank you for your attention

85. http://www.youtube.com/watch?v=WRwA291NAuM&feature=youtu.be

86. Lifetime CO2 emissions
One building, four designs
8000
Operational energy > embodied energy
7000
6000
5000 Sequestered
Operational
tonnes CO2
4000
Transport
3000 Maintenance
2000 Embodied
1000
0
-1000
Concrete Steel Timber TimberPlus
-2000

87. Embodied CO2
Steel
Concrete Aluminium
Wood

88. Overall CO2 emissions
Carbon Neutral for Timber
Negative for TimberPlus