The Rackwitz Symposium - a Milestone in Structural Reliability

1. The Rackwitz Symposium- a Milestone in Structural Reliability

2. Program 09:50 Opening address Prof. Dr. Konrad Zilch , Prof. Dr. Ton Vrouwenvelder 10:00 - 10:50 Technical Session I Prof. Dr. Peter Schiessl Prof. Dr. Konrad Zilch 10:50 - 11:10 Coffee break 11:10 - 12:30 Technical Session II Prof. Dr. Ove Ditlevsen Prof. Dr. John D. Sørensen Prof. Dr. Ton Vrouwenvelder 12:30 - 14:00 Lunch 14:00 - 15:30 Technical Session III Prof. Dr. Fabio Casciati Prof. Dr. Michael H. Faber Prof. Dr. Mahesh Pandey 15:30 - 16:00 Coffee break 16:00 - 17:00 Closing Ceremony Prof. Dr. Rüdiger Rackwitz, Prof. Dr. Konrad Zilch Prof. Dr. Michael H. Faber, Prof. Dr. Ton Vrouwenvelder On Temporal and Spatial Probabilistic Engineering Modeling

3. Rackwitz Symposium November 24, 2006 On Temporal and Spatial Probabilistic EngineeringModeling M. H. FaberChair of Risk and SafetyInstitute of Structural Engineering, ETH Swiss Federal Institute of Technology, Zurich

4. Contents of Presentation • Preamble and Disclaimer • The Context of Engineering Decision Making • A Basic Framework for Decision Making • Recent Developments in Systems Modeling- System modeling in risk assessment- Exposure analysis in regard to rockfall- Vulnerability of concrete structures- Robustness of structures- Large scale earthquake risk management • Concluding Remarks On Temporal and Spatial Probabilistic Engineering Modeling

5. Preamble and Disclaimer This page was intentional left blank ! On Temporal and Spatial Probabilistic Engineering Modeling

6. The Context of Engineering Decision Making • What do engineers do ? Hoover Dam - USA On Temporal and Spatial Probabilistic Engineering Modeling

7. The Context of Engineering Decision Making • What do engineers do ? Big Dig Boston/USA On Temporal and Spatial Probabilistic Engineering Modeling

8. The Context of Engineering Decision Making • What do engineers do ? Hong Kong Island - China On Temporal and Spatial Probabilistic Engineering Modeling

9. The Context of Engineering Decision Making • What are we up against? Fatigue Corrosion On Temporal and Spatial Probabilistic Engineering Modeling

10. The Context of Engineering Decision Making • What are we up against? Tornados and strong winds On Temporal and Spatial Probabilistic Engineering Modeling

11. The Context of Engineering Decision Making • What are we up against? Earthquakes On Temporal and Spatial Probabilistic Engineering Modeling

12. The Context of Engineering Decision Making • What are we up against? Earth slide Rock fall On Temporal and Spatial Probabilistic Engineering Modeling

13. The Context of Engineering Decision Making • What are we up against? Explosions Fires On Temporal and Spatial Probabilistic Engineering Modeling

14. The Context of Engineering Decision Making • What are we up against? Design error Over load On Temporal and Spatial Probabilistic Engineering Modeling

15. The Context of Engineering Decision Making • What are we up against? Bombs Airplane impacts On Temporal and Spatial Probabilistic Engineering Modeling

16. The Context of Engineering Decision Making • In what way are we important for society? Human capital Natural resources Protection of the environment Production Life safety Development and maintenance of infra-structure Economy On Temporal and Spatial Probabilistic Engineering Modeling

17. Ranking of decision alternatives according to expected utility Marginal Utility Expected Utility Probability of Outcome A Basic Framework for Decision Making • What is the basis for decision making? On Temporal and Spatial Probabilistic Engineering Modeling

18. Actions Models of real world Real World A Basic Framework for Decision Making How do engineers make decisons? Actions Actions Models of real world Models of real world Real World Real World Indicators On Temporal and Spatial Probabilistic Engineering Modeling

19. System understanding ! A Basic Framework for Decision Making What must be accounted for in engineering modeling?- Preferences (aim, purpose)- Consequences (states of marginal utility)- Uncertainties (aleatory and epistemic)- Temporal and spatial variations/dependencies- Options for decision making On Temporal and Spatial Probabilistic Engineering Modeling

20. Recent Developments in Systems Modeling How are consequences generated? Exposure Event Event generated consequences System change On Temporal and Spatial Probabilistic Engineering Modeling

21. Recent Developments in Systems Modeling How are consequences generated? On Temporal and Spatial Probabilistic Engineering Modeling

22. Recent Developments in Systems Modeling Modeling of consequences may be facilitated by explicitly accounting for: Direct consequences In-direct consequences Needs more emphasis Explicit treatment of epistemic uncertainty indicates where collectionof additional knowledge may be beneficial On Temporal and Spatial Probabilistic Engineering Modeling

23. Recent Developments in Systems Modeling Engineered systems exhibit generic characteristics On Temporal and Spatial Probabilistic Engineering Modeling

24. Actions Models of real world Real World Exposure Exposure Vulnerability Vulnerability Indicators Indicators Risk reduction measures Risk reduction measures Robustness Robustness Recent Developments in Systems Modeling Engineered systems exhibit generic characteristics Actions Actions Models of real world Models of real world Real World Real World Exposure Exposure Exposure Exposure Vulnerability Vulnerability Vulnerability Vulnerability Indicators Indicators Indicators Indicators Risk reduction measures Risk reduction measures Risk reduction measures Risk reduction measures Robustness Robustness Robustness Robustness On Temporal and Spatial Probabilistic Engineering Modeling

25. Recent Developments in Systems Modeling Exposure analysis in regard to rockfall On Temporal and Spatial Probabilistic Engineering Modeling

26. Recent Developments in Systems Modeling Exposure analysis in regard to rockfall On Temporal and Spatial Probabilistic Engineering Modeling

27. Recent Developments in Systems Modeling Exposure analysis in regard to rockfall On Temporal and Spatial Probabilistic Engineering Modeling

28. Recent Developments in Systems Modeling Exposure analysis in regard to rockfall Detachment modeling Fall modeling On Temporal and Spatial Probabilistic Engineering Modeling

29. Recent Developments in Systems Modeling Vulnerability of concrete structures in regard chlorides On Temporal and Spatial Probabilistic Engineering Modeling

30. Recent Developments in Systems Modeling Vulnerability of concrete structures in regard chlorides On Temporal and Spatial Probabilistic Engineering Modeling

31. Recent Developments in Systems Modeling Vulnerability of concrete structures in regard chlorides On Temporal and Spatial Probabilistic Engineering Modeling

32. Recent Developments in Systems Modeling Vulnerability of concrete structures in regard to chlorides Zone A Zone B On Temporal and Spatial Probabilistic Engineering Modeling

33. a. Component sector b. Basic inspection Recent Developments in Systems Modeling Vulnerability of concrete structures in regard to chlorides Zone B c. Model assessment Density function Correlation radius r r d. Idealization r On Temporal and Spatial Probabilistic Engineering Modeling

34. Recent Developments in Systems Modeling Vulnerability of concrete structures in regard to chloridesHow does deterioration develop over time and space? On Temporal and Spatial Probabilistic Engineering Modeling

35. Recent Developments in Systems Modeling Vulnerability of concrete structures in regard to chlorides Effect of inspection for one zone On Temporal and Spatial Probabilistic Engineering Modeling

36. Recent Developments in Systems Modeling Vulnerability of concrete structures in regard to chlorides Effect of inspection of several zones On Temporal and Spatial Probabilistic Engineering Modeling

37. Recent Developments in Systems Modeling Vulnerability of concrete structures in regard to chloridesEffect of maintenance on life cycle costs On Temporal and Spatial Probabilistic Engineering Modeling

38. Recent Developments in Systems Modeling Vulnerability of concrete structures in regard to chloridesRepair optimizationHow large a proportion of the surface should exhibit initiated corrosion before repair? On Temporal and Spatial Probabilistic Engineering Modeling

39. Recent Developments in Systems Modeling Vulnerability of concrete structures in regard to chloridesAcceptance criteria for new structuresWhat can be accepted in terms of spatial variability of material characteristics? On Temporal and Spatial Probabilistic Engineering Modeling

40. Recent Developments in Systems Modeling Robustness of structures On Temporal and Spatial Probabilistic Engineering Modeling

41. Recent Developments in Systems Modeling Robustness of structures An assessment framework Exposure Exposure On Temporal and Spatial Probabilistic Engineering Modeling

42. Recent Developments in Systems Modeling Robustness of structures An assessment framework Exposure On Temporal and Spatial Probabilistic Engineering Modeling

43. Recent Developments in Systems Modeling Robustness of structures Calculation of Risk On Temporal and Spatial Probabilistic Engineering Modeling

44. Direct Risk Direct Risk +Indirect Risk IRob = Recent Developments in Systems Modeling Features of the proposed index- Assumes values between zero and one- Measures relative risk only- Dependent upon the probability of damage occurrence - Dependent upon consequences Robustness of structures On Temporal and Spatial Probabilistic Engineering Modeling

45. Recent Developments in Systems Modeling The framework easily facilitates decision analysis - Choice of the physical system - Choice of inspection and repair- Choices to reduce consequences Robustness of structures On Temporal and Spatial Probabilistic Engineering Modeling

46. Recent Developments in Systems Modeling Robustness of structures • Parallel system with n elements • Subjected to different types of exposures • Perfect ductile / brittle • Load distribution after component failure • Element damage / system failure • The one element case represents series systems • Consequences of system failure is set equal to 100 times the consequences of component failure On Temporal and Spatial Probabilistic Engineering Modeling

47. Recent Developments in Systems Modeling Robustness of structures Number of components – ductile material • The greater the number of components, the more robust • One component – Small robustness • One component – Series system On Temporal and Spatial Probabilistic Engineering Modeling

48. Recent Developments in Systems Modeling Robustness of structures Load variability – ductile material • Higher CoV leads to less robustness • Higher Cov increases the probability that the system fails if one component is damaged • Here uncorrelated resistance is assumed – Correlation has the same effect as reducing the number of components On Temporal and Spatial Probabilistic Engineering Modeling

49. Recent Developments in Systems Modeling Robustness of structures Load variability – brittle material • No residual carrying capacity • Cascading system failure • The robustness is close to zero • Indirect risks are dominating • Probabilities for damage states are low – or failure consequences high On Temporal and Spatial Probabilistic Engineering Modeling

50. Recent Developments in Systems Modeling Large scale earthquake risk management On Temporal and Spatial Probabilistic Engineering Modeling