2. LESSONS LEARNED FROM PAST NOTABLE DISASTERS MEXICO PART 3B: EARTHQUAKE VULNERABILITY OF BUILDINGS Walter Hays, Global Alliance for Disaster Reduction, Vienna, Virginia, USA

3. MEXICO

4. MEXICO IS ON THE PACIFIC RIM WHERE A LARGE FRACTION OF THE GLOBAL SEISMICITY OCCURS

6. NATURAL HAZARDS THAT HAVE CAUSED DISASTERS IN MEXICO FLOODS SEVERE WINDSTORMS EARTHQUAKES VOLCANIC ERUPTIONS ENVIRONMENTAL CHANGE GLOBAL CLIMATE CHANGE HIGH BENEFIT/COST FROM BECOMING DISASTER RESILIENT GOAL: PROTECT PEOPLE AND COMMUNITIES

7. MEXICO EXPERIENCED A M8.1 SUBDUCTION ZONE QUAKE IN 1985

8. BUILDING VULNERABILITY WAS (AND STILL IS) A MAJOR FACTOR IN MEXICO’S LOSSES IN 1985

9. Mexico’s building stock, like the building stock of all countries, has vulnerabilities as a result of irregularities in elevation and plan, construction materials, and the underlying soil

10. HAZARDSHAZARDS ELEMENTS OF EARTHQUAKE RISK EXPOSUREEXPOSURE VULNERABILITYVULNERABILITY LOCATIONLOCATION RISKRISK

11. EARTHQUAKE HAZARD MODEL EARTHQUAKE HAZARD MODEL SEISMICITY TECTONIC SETTING & FAULTS TECTONIC SETTING & FAULTS

12. TECTONIC DEFORMATION EARTHQUAKE TSUNAMI GROUND SHAKING FAULT RUPTURE FOUNDATION FAILURE SITE AMPLIFICATION LIQUEFACTION LANDSLIDESAFTERSHOCKSSEICHE DAMAGE/LOSS DAMAGE/ LOSS DAMAGE/LOSS

13. EXPOSURE MODEL EXPOSURE MODEL LOCATION OF STRUCTURE IMPORTANCE AND VALUE OF STRUCTURE AND CONTENTS

14. VULNERABILITY MODEL VULNERABILITY MODEL QUALITY OF DESIGN AND CONSTRUCTION ADEQUACY OF LATERAL-FORCE RESISTING SYSTEM

15. UNREINFORCED MASONRY, BRICK OR STONE REINFORCED CONCRETE WITH UNREINFORCED WALLS INTENSITY REINFORCED CONCRETE WITH REINFORCEDWALLS STEEL FRAME ALL METAL & WOOD FRAME VVIVIIVIIIIX 3530 25 20 15 10 5 0 MEAN DAMAGE RATIO, % OF REPLACEMENT VALUE CONSTRUCTION MATERIALS HAVE DIFFERENT VULNERABILITIES TO GROUND SHAKING

16. INADEQUATE RESISTANCE TO HORIZONTAL GROUND SHAKING EARTHQUAKES SOIL AMPLIFICATION PERMANENT DISPLACEMENT (SURFACE FAULTING & GROUND FAILURE) IRREGULARITIES IN ELEVATION AND PLAN FIRE FOLLOWING RUPTURE OF UTILITIES LACK OF DETAILING AND CONSTRUCTION MATERIALS INATTENTION TO NON- STRUCTURAL ELEMENTS CAUSES OF DAMAGE “DISASTER LABORATORIES”

17. MEXICO CITY HAS SOFT SOILS THAT AMPLIFY GROUND SHAKING MEXICO CITY HAS SOFT SOILS THAT AMPLIFY GROUND SHAKING

18. MEXICO CITY HAS VULNERABLE SHORT BUILDINGS

19. MEXICO CITY HAS VULNERABLE TALL BUILDINGS

20. POLICY ADOPTION RISK ASSESSMENT VULNERABILITYVULNERABILITY EXPOSUREEXPOSURE EVENTEVENT POLICY ASSESSMENT COSTCOST BENEFITBENEFIT CONSEQUENCESCONSEQUENCES REDUCING BUILDING VULNERABILITY REDUCES THE COMMUNITY’S RISK AN EARTH- QUAKE EXPECTED LOSS

21. VULNERABILITY REDUCTION IS A CLASSIC EXAMPLE OF STRATEGIC COLLABORATION

24. ACKNOWLEDGMENT: The vulnerability analyses that follow are based on global experience of a major reinsurance company that was shared for the benefit of all countries having buildings at risk in future earthquakes.

25. ANALYSIS OF VULNERABILITY DUE TO IRREGULARITIES IN BUILDING ELEVATIONS

26. RELATIVE VULERABILITY [1 (Best) to 10 (Worst)] 1-2 ANALYSIS OF VULNERABILITY LOCATIONS OF POTENTIAL FAILURE None, if attention given to foundation and non structural elements. Rocking may crack foundation and structure. BUILDING ELEVATION Box

27. RELATIVE VULERABILITY [1 (Best) to 10 (Worst)] 1 ANALYSIS OF VULNERABILITY LOCATIONS OF POTENTIAL FAILURE None, if attention given to foundation and non structural elements. Rocking may crack foundation. BUILDING ELEVATION Pyramid

28. RELATIVE VULERABILITY [1 (Best) to 10 (Worst)] 2 - 3 ANALYSIS OF VULNERABILITY LOCATIONS OF POTENTIAL FAILURE Vertical transition in mass, stiffness, and damping may cause failure at foundation and transition points at each floor. BUILDING ELEVATION Multiple Setbacks

29. RELATIVE VULERABILITY [1 (Best) to 10 (Worst)] 4 - 6 ANALYSIS OF VULNERABILITY LOCATIONS OF POTENTIAL FAILURE Top heavy, asymmetrical structure may fail at foundation due to rocking and overturning. BUILDING ELEVATION Inverted Pyramid

30. RELATIVE VULERABILITY [1 (Best) to 10 (Worst)] 5 - 6 ANALYSIS OF VULNERABILITY LOCATIONS OF POTENTIAL FAILURE Asymmetry and horizontal transition in mass, stiffness and damping may cause failure where lower and upper structures join. BUILDING ELEVATION “L”- Shaped Building

31. RELATIVE VULERABILITY [1 (Best) to 10 (Worst)] 3 - 5 ANALYSIS OF VULNERABILITY LOCATIONS OF POTENTIAL FAILURE Vertical transition and asymmetry may cause failure where lower part is attached to tower. BUILDING ELEVATION Inverted “T”

32. RELATIVE VULERABILITY [1 (Best) to 10 (Worst)] 4 - 5 ANALYSIS OF VULNERABILITY LOCATIONS OF POTENTIAL FAILURE Top heavy asymmetrical structure may fail at transition point and foundation due to rocking and overturning. BUILDING ELEVATION Overhang

33. SOFT-STOREY BUILDINGS ARE THE MOST VULNERABLE

34. RELATIVE VULERABILITY [1 (Best) to 10 (Worst)] 6 - 7 ANALYSIS OF VULNERABILITY LOCATIONS OF POTENTIAL FAILURE Horizontal and vertical transitions in mass and stiffness may cause failure on soft side of first floor; rocking and overturning. BUILDING ELEVATION Partial “Soft” Story

35. RELATIVE VULERABILITY [1 (Best) to 10 (Worst)] 8 - 10 ANALYSIS OF VULNERABILITY LOCATIONS OF POTENTIAL FAILURE Vertical transitions in mass and stiffness may cause failure on transition points between first and second floors. BUILDING ELEVATION “Soft” First Floor

36. RELATIVE VULERABILITY [1 (Best) to 10 (Worst)] 9 - 10 ANALYSIS OF VULNERABILITY LOCATIONS OF POTENTIAL FAILURE Horizontal and vertical transitions in mass and stiffness may cause failure at transition points and possible overturning. BUILDING ELEVATION Combination of “Soft” Story and Overhang

37. RELATIVE VULERABILITY [1 (Best) to 10 (Worst)] 9 - 10 ANALYSIS OF VULNERABILITY LOCATIONS OF POTENTIAL FAILURE Horizontal and vertical transition in mass and stiffness may cause failure columns. BUILDING ELEVATION Sports Stadiums

38. RELATIVE VULERABILITY [1 (Best) to 10 (Worst)] 10 ANALYSIS OF VULNERABILITY LOCATIONS OF POTENTIAL FAILURE Horizontal transition in stiffness of soft story columns may cause failure of columns at foundation and/or contact points with structure. BUILDING ELEVATION Building on Sloping Ground

39. ANALYSIS OF VULNERABILITY DUE TO IRREGULARITIES IN PLAN

40. RELATIVE VULERABILITY [1 (Best) to 10 (Worst)] 1 ANALYSIS OF VULNERABILITY POTENTIAL PROBLEMS None, if symmetrical layout maintained. FLOOR PLAN Box

41. RELATIVE VULERABILITY [1 (Best) to 10 (Worst)] 2 - 4 ANALYSIS OF VULNERABILITY POTENTIAL PROBLEMS Differences in length and width will cause differences in strength, differential movement, and possible overturning. FLOOR PLAN Rectangle

42. RELATIVE VULERABILITY [1 (Best) to 10 (Worst)] 2 - 4 ANALYSIS OF VULNERABILITY POTENTIAL PROBLEMS Asymmetry will cause torsion and enhance damage at corners. FLOOR PLAN Street Corner

43. RELATIVE VULERABILITY [1 (Best) to 10 (Worst)] 4 ANALYSIS OF VULNERABILITY POTENTIAL PROBLEMS Open space in center reduces resistance and enhance damage at corner regions. FLOOR PLAN Courtyard in Corner

44. RELATIVE VULERABILITY [1 (Best) to 10 (Worst)] 4 - 5 ANALYSIS OF VULNERABILITY POTENTIAL PROBLEMS Asymmetry will cause torsion and enhance damage along curved boundary. FLOOR PLAN Theaters

45. RELATIVE VULERABILITY [1 (Best) to 10 (Worst)] 5 - 10 ANALYSIS OF VULNERABILITY POTENTIAL PROBLEMS Asymmetry will enhance damage at corner regions. FLOOR PLAN “U” - Shape

46. RELATIVE VULERABILITY [1 (Best) to 10 (Worst)] 5 - 7 ANALYSIS OF VULNERABILITY POTENTIAL PROBLEMS Directional variation in stiffness will enhance damage at intersecting corner. FLOOR PLAN “H” - Shape

47. RELATIVE VULERABILITY [1 (Best) to 10 (Worst)] 8 ANALYSIS OF VULNERABILITY POTENTIAL PROBLEMS Asymmetry will cause torsion and enhance damage at intersection and corners. FLOOR PLAN “L” - Shape

48. RELATIVE VULERABILITY [1 (Best) to 10 (Worst)] 8 - 10 ANALYSIS OF VULNERABILITY POTENTIAL PROBLEMS Asymmetry and directional variation in stiffness will enhance torsion and damage at intersecting. FLOOR PLAN Complex Floor Plan

49. ANALYSIS OF VULNERABILITY DUE TO IRREGULARITIES IN INTERNAL PROPERTIES

50. ANALYSIS OF VULNERABILITY POTENTIAL PROBLEMS Asymmetry and discontinuities in strength will cause torsion and concentrate stress around the opening. INTERNAL PROPERTIES Opening in Shear Wall

51. ANALYSIS OF VULNERABILITY POTENTIAL PROBLEMS Asymmetry and variable stiffness will cause torsion and cracking/failure at staircase and elevator well. INTERNAL PROPERTIES Opening in Shear Wall

52. ANALYSIS OF VULNERABILITY POTENTIAL PROBLEMS Variable stiffness will enhance cracking and failure on weaker side of structure. INTERNAL PROPERTIES Shear Wall or Retaining Wall on only one side

53. ANALYSIS OF VULNERABILITY POTENTIAL PROBLEMS Asymmetry and irregularities will cause torsion and enhance failure at all points of irregularity. INTERNAL PROPERTIES Different or Irregular Spans; short columns

54. ANALYSIS OF VULNERABILITY POTENTIAL PROBLEMS Vertical transitions in seismic resistance will enhance failure at the “short columns”. INTERNAL PROPERTIES Window Bands Interrupting In- Fill Walls

55. ANALYSIS OF VULNERABILITY POTENTIAL PROBLEMS Vertical transitions in stiffness will enhance failure at the transition points. INTERNAL PROPERTIES Three Story Frame

56. ANALYSIS OF VULNERABILITY POTENTIAL PROBLEMS Vertical transitions in mass will enhance cantilever action, overturning moment, and failure at transition points. INTERNAL PROPERTIES Offset Columns

57. ANALYSIS OF VULNERABILITY POTENTIAL PROBLEMS Horizontal transition in depth of foundation will cause rocking and failure at edges. INTERNAL PROPERTIES Irregular Foundation

58. ANALYSIS OF VULNERABILITY POTENTIAL PROBLEMS Discontinuities in mass, stiffness, and damping will be enhanced at all transition points. INTERNAL PROPERTIES Industrial or Commercial Facility

59. ANALYSIS OF VULNERABILITY POTENTIAL PROBLEMS Top-heavy structures are vulnerable to distant earthquakes and resonance of thick soft soils because of vertical transition in mass.. Rocking, overturning, and foundation failure are enhanced. INTERNAL PROPERTIES Water Tower DUPONT

60. EMERGING TECHNOLOGIES FOR REDUCING VULNERABILITIES IN PLAN AND ELEVATION

61. EMERGING TECHNOLOGIES AUTOMATED CONSTRUCTION EQUIPMEMT PREFABRICATION AND MODULARIZATION ADVANCED MATERIALS (E.G., COMPOSITES) COMPUTER AIDED DESIGN PERFORMANCE BASED CODES AND STANDARDS ACTIVE AND PASSIVE ENERGY DISSIPATION DEVICES (E.G., BASE ISOLATION) REAL-TIME MONITORING AND WARNING SYSTEMS COMPUTER AIDED DESIGN PERFORMANCE BASED CODES AND STANDARDS ACTIVE AND PASSIVE ENERGY DISSIPATION DEVICES (E.G., BASE ISOLATION) REAL-TIME MONITORING AND WARNING SYSTEMS