1. Multi hazard approach to design of civil structures April 29 th 2010 Multi hazard approach to design of civil structures Domenico Asprone Dipartimento di Ingegneria Strutturale Università degli Studi di Napoli Federico II

2. Multi hazard approach to design of civil structures April 29 th 2010 A strategic structure could be subject to more than one critical action during its service life. A sustainable design needs to consider all the possible critical actions which the structure could be subjected to. Given the uncertainty involved, the sustainable design needs to be addressed based on a probabilistic framework. Introduction

3. Multi hazard approach to design of civil structures April 29 th 2010 Risk, hazard, vulnerability and exposure are probabilistic quantities. riskexposure vulnerability hazard Multi-hazard structural design/assessment

4. Multi hazard approach to design of civil structures April 29 th 2010 Hazard (a) (b)

5. Multi hazard approach to design of civil structures April 29 th 2010 Hazard

6. Multi hazard approach to design of civil structures April 29 th 2010 Hazard

7. Multi hazard approach to design of civil structures April 29 th 2010 Vulnerability Seismic vulnerability

8. Multi hazard approach to design of civil structures April 29 th 2010 Vulnerability Non-structural elements vulnerability

9. Multi hazard approach to design of civil structures April 29 th 2010 Vulnerability Tsunami vulnerability

10. Multi hazard approach to design of civil structures April 29 th 2010 Vulnerability Termite vulnerability

11. Multi hazard approach to design of civil structures April 29 th 2010 Exposure Time dependence

12. Multi hazard approach to design of civil structures April 29 th 2010 Exposure Seismic zones

13. Multi hazard approach to design of civil structures April 29 th 2010 Multi-hazard structural design/assessment Structural engineering issue: In case of multiple hazard, the design/assessment criterion can be written as Total probability of collapse Acceptable threshold

14. Multi hazard approach to design of civil structures April 29 th 2010 Italian hazard for civil structures Earthquake; Extreme service conditions; Wind; Snow; Explosions; Fire; Flood; Landslide; Vulcan eruptions; …

15. Multi hazard approach to design of civil structures April 29 th 2010 Seismic hazard Peak Ground Acceleration

16. Multi hazard approach to design of civil structures April 29 th 2010 Seismic hazard 36 Seismogenic zones

17. Multi hazard approach to design of civil structures April 29 th 2010 Seismic hazard Attenuation law

18. Multi hazard approach to design of civil structures April 29 th 2010 Seismic hazard PGA distribution

19. Multi hazard approach to design of civil structures April 29 th 2010 Seismic hazard Grid spacing 0.05° long-lat

20. Multi hazard approach to design of civil structures April 29 th 2010 Seismic hazard Pratica di Mare hazard Return Period PGA Limit states

21. Multi hazard approach to design of civil structures April 29 th 2010 Man-made blast hazard Scenario definition 30%70% Explosion takes place inside the structureExplosion takes place outside a 10 m stand-off distance from the structure 10%90% Truck bomb W=15,000kg - 25,000kg Car bomb W=200 kg - 500kg 20% 1 st floor: Car bomb W=200 kg – 500 kg 2 nd floor: Backpack bomb W=15 kg – 35 kg 3 rd floor: Backpack bomb W=15 kg – 35 kg 4 th floor: Backpack bomb W=15 kg – 35 kg 5 th floor: Backpack bomb W=15 kg – 35 kg Blast scenario

22. Multi hazard approach to design of civil structures April 29 th 2010 Blast loading The induced overpressure normally consists of a positive decaying phase followed by a weaker negative phase. The most critical aspect with respect to the safety of the structure regards progressive collapse mechanisms on the damaged structure.

23. Multi hazard approach to design of civil structures April 29 th 2010 Blast Scenarios Leading to Collapse

24. Multi hazard approach to design of civil structures April 29 th 2010 Wind hazard Critical issues: Wind direction; Low velocity characterization; Spatial mesh refining; Season variation; Reliable hazard characterization.

25. Multi hazard approach to design of civil structures April 29 th 2010 Multi-hazard structural design/assessment Structural engineering issue: In case of multiple hazard, the design/assessment criterion can be written as Total probability of collapse Acceptable threshold

26. Multi hazard approach to design of civil structures April 29 th 2010 Thank you