FAO Seminar on Forests and Natural Disasters

Transcription

1 FAO Seminar on Forests and Natural Disasters Disaster-Resistant Timber Construction 4 November Rotorua Professor Andy Buchanan University of Canterbury

2 2010 & 2011 earthquakes Japan California Taiwan New Zealand Chile Movement of fault = 40mm per year

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5 Christchurch earthquakes Main quake: 4 September 2010, 4.30am. M 7.1 No deaths Aftershock: 22 February 2011, 1 pm. M deaths

6 Building collapses. Loss of life 115 deaths in CTV. 18 deaths in PGC 42 deaths in other buildings (masonry) 7 deaths in rockfall etc. 182 total deaths

7 Liquefaction damage

8 Vertical accelerations Roof shaken off Timber house structurally safe

9 Wall bracing failures

10 After Soft storey collapses Before

11 Masonry buildings

12 Christchurch after the quake

13 Re-building Christchurch What kind of city do we want? Warren and Mahoney

14 Re-building Christchurch Wood is part of the solution Old Government Buildings, Wellington, 1876

15 International 7 storeys Berlin (Glulam) 6 storeys Switzerland (Light timber frame) 9 storeys London (X-Lam panels)

16 New technology New materials LVL CLT New fasteners Screws Rivets New structural concepts Post-tensioning Hi-Tech manufacturing

17 New materials Glulam LVL Laminated Veneer Lumber CLT Cross Laminated Timber

18 New fasteners Rivets Screws

19 Rocking Concrete Systems University of California, San Diego

20 Post-tensioned timber frames Post-tensioning solves problem of moment connections for heavy timber frames

21 Post-tensioned timber walls U U U

22 Top-lateral Force [kn] Top-lateral Force [kn] Testing at Canterbury University Hybrid specimen 1 - HY Hybrid specimen 3 HY f p0 = 0.8f py -15 f p0 = 0.6f py ,05-0,04-0,03-0,02-0,01 0 0,01 0,02 0,03 0,04 0,05 Drift Hybrid specimen 2 HY2 f p0 = 0.8f py -0,05-0,04-0,03-0,02-0,01 0 0,01 0,02 0,03 0,04 0,05 Drift ,05-0,04-0,03-0,02-0,01 0 0,01 0,02 0,03 0,04 0,05 Drift Hybrid specimen 4 HY4 f p0 = 0.6f py -0,05-0,04-0,03-0,02-0,01 0 0,01 0,02 0,03 0,04 0,05 Drift

23 Post-tensioned timber beams

24 UC Test Building Post-tensioning tendons Frames Walls

25 UC Test Building Post-tensioning University of Canterbury laboratories

26 Expan Head Office

27 Expan Head Office No damage in Feb earthquake

28 NMIT Building, Nelson NMIT Arts and Media Building, Nelson. ISJ Architects, Aurecon, Davis Langdon, Arrow International

29 Massey University, Wellington Massey University Wellington

30 Massey University, Wellington Massey University, Wellington. Athfield Architects, Dunning Thornton

31 Massey University, Wellington Massey University, Wellington. Athfield Architects, Dunning Thornton

32 Carterton, Wellington Opus architects and engineers

33 Kaikoura Museum, library, council offices, Kaikoura DC All timber. No concrete. CLT + LVL walls.

34 Re-building Christchurch Sheppard and Rout Architects, Kirk Roberts Engineers

35 Re-building Christchurch

36 Re-building Christchurch

37 Re-building Christchurch

38 Re-building Christchurch Opus International Architects and Engineers

39 Re-building Christchurch

40 Re-building Christchurch

41 Re-building Christchurch

42 Re-building Christchurch Rick Proko Architects, Ruamoko Engineers

43 Re-building Christchurch Base-isolated building. Frames both directions with concrete columns and post-tensioned LVL beams.

44 Re-building Christchurch

45 Why use wood? Constructability Sustainability Renewability Availability Weight Cost Cost effective High performance Timber building systems How to make it happen? Fire safety, durability, acoustics, energy

46 The Supply Chain Forest owner Logs Processor Wood products Fabricator Structural elements Erector Structural skeleton Contractor Whole building Building owner They may have to take some risks

47 How to reduce the risk? PROVIDE CONFIDENCE Government support Research funding Support designers Educate new players Share knowledge Codes and Standards Design Guides

48 Fire safety Heavy timber has excellent fire resistance

49 Sustainability Emissions to the atmosphere Carbon storage in building materials

50 Sustainability Timber buildings can be carbon-neutral Alternative to steel and concrete Concrete - 8% of global CO2 emissions Kyoto Protocol - harvested wood products Carbon Tax or Emissions Trading Laws

51 Low-damage wood solutions Cost effective High performance Timber building systems Residential buildings Commercial buildings Educational buildings Industrial buildings Resistance to wind and earthquakes

52 Conclusions We have the technology, more coming We have the materials, hybrids coming We have the structural systems We need help from industry and government Low-damage timber buildings for a sustainable future