1. STRUCTURAL FAILURES AND COLLAPSES Toni Kekki / NKUAS

2. ENGINEERING IN GENERAL Toni Kekki / NKUAS Solving problems Solving problems with sufficient safety according to loads and stresses, and this all has to be economically and environmentally sustainable

3. ENGINEERING IN GENERAL Toni Kekki / NKUAS safety cost Safety factor = 1.0 Safety according to national regulation (Unnecesserary) extra cost Unaccep- table zone Danger zone

4. Safety Investigation Authority Toni Kekki / NKUAS

5. Safety Investigation Authority Toni Kekki / NKUAS Mandatory authority for international regulations on airborne, maritime and railroad transportation Building investigation is mandated by Finnish government without international regulation SIA works under Ministy of Justice as an independent authority. Funding comes from government.

6. LAST FEW YEARS IN FINLAND... Toni Kekki / NKUAS On winter 2009 – 2010 we had 99 registered roof collapses or structural failures with risk to life. On winter 2010-2011 same count was 117! This winter count is so far 22. Average 2008-2010 was 62 / year  Absolutely unacceptable!

7. Toni Kekki / NKUAS Not nearly enough snowload to cause failure

8. Toni Kekki / NKUAS The most stressed joints were not calculated at all. Truss-analogy and hand-method calculations were totally deficient. Designer was experienced steelstructure expert! Section of a structure.

9. Toni Kekki / NKUAS

10. Trusses without proper buckling support

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12. Conditions too moist for plywood; not how it was designed. Connection to foundation was rotten; concrete was poured around wood without isolative material

13. WHAT CAUSES FAILURES Toni Kekki / NKUAS

14. WHAT CAUSES FAILURES Toni Kekki / NKUAS

15. CASE: Industrial facility in North-Karelia Part of a roof collapsed suddenly and without pre-warning Personal injuries were avoided. Interruption of a production and machinery damages caused losses in income. Construction was made in 1996. New enlargement was made in 2002. In this project roof shape was modified.

16. Toni Kekki / NKUAS CASE: Industrial facility in North-Karelia

17. Toni Kekki / NKUAS

18. CASE: Industrial facility in North-Karelia

19. Toni Kekki / NKUAS CASE: Industrial facility in North-Karelia

20. Toni Kekki / NKUAS CASE: Industrial facility in North-Karelia PartForce (kN)Original force (kN) Chance in % P9-43,26-33,38130 P7-48,71-28,41172 D8+4,61+0,76607 D9+18,23+10,15180 D10-30,75-28,42108 P12+35,53+30,48117 P13+25,18+21,99115 V4-10,53-3,61292

21. THINGS TO REMEMBER: Toni Kekki / NKUAS Collapses don’t just happen. They have usually logical explanation and, sad but true, chain of events. Computer is a good employee but really bad boss! User is the boss and always responsible of results  make necessary checkings!!! Design and install all structures so well that you and your family could walk underneath this structure.

22. SOME LINKS TO FOLLOW Toni Kekki / NKUAS Animation about sinking of Estonia-ferry: http://www.youtube.com/watch?v=ke6zmUX9ay8 http://www.youtube.com/watch?v=ke6zmUX9ay8 Pulp silo baseplate failure (insufficient piling) http://www.youtube.com/watch?v=doM9KPEIuS0 http://www.youtube.com/watch?v=doM9KPEIuS0 National Geographic: Seconds from disaster Skywalk: http://www.youtube.com/watch?v=yoGGMdktsRMhttp://www.youtube.com/watch?v=yoGGMdktsRM Hotel New World: http://www.youtube.com/watch?v=DtYKCu9XBDA&feature=relmfu http://www.youtube.com/watch?v=DtYKCu9XBDA&feature=relmfu Korea department store: http://www.youtube.com/watch?v=KDttjA3-_4Ehttp://www.youtube.com/watch?v=KDttjA3-_4E

23. Toni Kekki / NKUAS ”The important thing is not to stop questioning. Curiosity has its own reason for existing” -Albert Einstein-