1. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Observations and Lessons on Earthquake and Tsunami Risk Mitigation in Padang, Indonesia Nick Alexander, Degenkolb Engineers Veronica Cedillos, GeoHazards International Louise Comfort, University of Pittsburgh

2. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Reconnaissance Team Members EERI Team Deierlein, Alexander, Cedillos, Hausler, Henderson, Comfort, Hart, Rudianto, Wijanto, Wood. Other US Participants Mooney & McGarr, USGS Franco, DiBarnaba, Sandoval Kizzee, Cabrera, Scawthorn International Andalas University ITB University Indonesian Society Geotech. Engrg. Nanyang Tech. University New Zealand Engineers

3. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Acknowledgements NSF: EERI Learning From Earthquakes Program with additional support from Blume Earthquake Engineering Center, Stanford Pacific Earthquake Engineering Research (PEER) Center USGS University of Pittsburgh, GSPIA Team host organizations: –Degenkolb Engineers –Forell Elsesser –Build Change –GeoHazards International –Risk Management Solutions, Inc.

4. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE History of Padang Batang Arau River Old City City Center Padang City 17 th Century Trading Center Population 900,000 (20x growth since 1940) Capital of West Sumatra

5. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Impact – Road Damage Sengara, I.W. et al., 2009

6. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Impact – Bridge Damage

7. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Impact – Foundation Damage Provincial Public Works Building 4 story, built 1976 Soft/Weak first story Columns experienced 12” drift Site experienced liquefaction 100 m from Batang Arau River

8. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Impact – Utility and Lifeline Systems Airport –closed 3 hrs, regular ops 1 day Electric Power –distributed transformer damage –restored 20% within 5 days –fully restored within 8 days Phone/Communication –landlines OK, cell restored within days Water –1 of 2 main supply pipes and 1 of 2 main distillation tanks ruptured –back to 60% within 2 weeks Port Facility –little damage, south of town damaged water treatment

9. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Outline Building Types and Occupancies Acceleration Response vs Design Base Shear in Building Code Typical Building Damage & Collapse Mode Building Design & Construction in Padang Building Case Studies Summary of Buildings Performance Improving Buildings Performance

10. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Building Types and Occupancies Government Offices Schools Hospitals Commercial Buildings –Offices and Banks –Retail Malls –Hotels –Home-shops (Ruko) Residential Homes Primarily Reinforced Concrete Frames with Brick Infill Walls URM, Confined Masonry, Wood Few Steel Moment Frames

11. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Comparison to Building Code Building Code Requirements 1970: Base shear = 0.1g, working stress design 1987: PGA = 0.25 – 0.36g, 2 soil types, inelastic R=4 2002: Similar to 1987, 3 soil types, capacity design increase in short period spectral demands Spectral Acceleration - 5% damping - NS component - stiff soil site

12. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Building Damage and Collapse Story Collapse Complete Collapse

13. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Brick Masonry Infill Wall & NS Damage Building Damage and Collapse

14. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Building Design & Construction Seismic Design Codes –Established by national committee (Jakarta) –First established 1970, updates in 1987 and 2002 –Currently revising to model after U.S. IBC & ASCE 7 Expertise of Local Professionals –Engineering education at university –Little professional development & continuing education in Padang –Little training/certification of contractors Code Compliance & Quality Assurance –Field observations and interviews suggest lack of compliance –Problems most significant with small projects and renovations –Common to other developing countries (lack of well established process, insufficient resources to implement, lack of education)

15. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Building Case Studies SMK 9 M Djamil Hospital Provincial Planning Building Ambacang Hotel Hotel Mariani Dutch Colonial & Chinatown Buildings Lasano Kampong Dalam Village Padang Ruko Buildings

16. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE SMK 9 School High School 3 story, built 1997 Partial floor and stair collapse Weak/Captive Columns 2 casualties (non-students) many students at time of EQ EQ Drills teach duck and cover Students ran out of building No student victims

17. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Sentral Plasa Raya Mall 3 story concrete frame/brick infill building built in 2005 Back end collapsed Brick infill failures Non-structural damage FRONT END BACK END

18. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Sentral Plasa Raya Mall Heavy mass at the back end Column detailing: Small ties with 90 degree hooks Column failure at lap splice

19. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Provincial Planning Building 3 story, 1981-83 1st Floor Collapse –Configuration –Design and Detailing smooth bars small ties w/ 90 degree hooks –Construction quality 2 Casualties –80 occupants in building during EQ Impact on rebuilding effort –Many files still in building

20. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE M Djamil Hospital Largest hospital in Padang (800+ beds) 13 buildings, only 1 building sustained major damage Outpatient Building –3 stories, built in 1982 –First floor collapsed –No casualties –Pounding between segments

21. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE M Djamil Hospital Vaulted roof at the atrium Damage at the one end of the cross shape

22. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Ambacang Hotel Originally a 1900 Dutch 2-story masonry warehouse, later expanded to 5 stories Both concrete & steel frames Irregular, no clear load path Partial story collapse at 2 nd Floor of main building BEFORE EQ

23. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Ambacang Hotel Separate 6 story steel building (built in 2005) fully collapsed Poor moment frame connection detail No continuity plate Weak way bending Slender columns 200 fatalities in the hotel (est.)

24. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Hotel Mariani 4-6 story 2006 steel building collapsed, 3-story 1963 concrete building damaged but survived One of few steel buildings in Padang Weak axis column bending led to progressive collapse

25. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Hotel Mariani Moment frame failed weak way Building collapsed towards the back

26. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Dutch Colonial & Chinatown Districts 100+ year old buildings, adjacent to the river Unreinforced masonry buildings w/ wood roofs & floors Out-of-plane collapse

27. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Lasano Kampong Dalam Village Small village in hills outside of Pariaman URM, confined masonry URM houses sustained the most damage Settlement resulted in damage to several homes Liquefaction

28. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Lasano Kampong Dalam Village Confined Masonry Buildings Improved version of URM Promoted in rural areas in Indonesia Reinforced concrete element for confinement Fairly well performance

29. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Ruko Buildings in Padang Ruko – very common in Padang 2 to 3-story tall commercial & residential Stiffness irregularity Various performance Some collapse some minor damage No comprehensive plan check

30. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Performance of Concrete Buildings Soft/weak story Weak columns Inadequate steel reinforcement –not enough steel –nonconforming details Poor quality concrete Insufficient lateral strength and stiffness Brittle architectural finishes

31. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Performance of Concrete Buildings Damage to older buildings is not unexpected Damage to newer buildings was greater than expected

32. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Performance of Steel Buildings Poor moment frame detailing –Weak way bending –Poor welding –Nonconforming to code Slender column sections for moment frame Insufficient strength and stiffness - significant drift Non-familiarity with steel design and construction in the area

33. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Performance of Masonry Buildings Unreinforced Masonry –Poor quality materials and workmanship –No confinement to prevent out-of-plane wall failure Confined Masonry –Performed fairly well –Guidelines available for single family homes but no code provision

34. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Improving Buildings Performance Proper enforcement & implementation of the Building Code –continuing education –quality assurance –training/certifications of contractors Building code provision for residential homes and ruko/homeshops Challenge to implement these in the re- construction effort

35. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Outline Tsunami Risk Preparedness Efforts Tsunami Evacuation during 9/30 Earthquake Performance of Tsunami Evacuation Structures Observations & Lessons Learned

36. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Tsunami Risk in Padang One of the highest tsunami risks in the world National Geographic Indonesia Risk is a function of the hazard and exposure Padang

37. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Tsunami Hazard in Padang Killed more than half the population in Banda Aceh Padang is exposed to a similar hazard from same fault Indian Ocean Tsunami December 2004 After 2004 Tsunami Before 2004 Tsunami Banda Aceh

38. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Seismological Background

39. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Tsunami Mechanism

40. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Tsunami Mechanism

41. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE First big rupture on the Sundamegathrust occurred in 2004 The second big rupture occurred in March 2005 The third rupture occurred in a series of events, with an aftershock of M7.9 Northern part of Mentawai patch remains locked Source: Kerry Sieh

42. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Vulnerable Terrain

43. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE 900,000 people Almost 9,000/km 2 at city center >½ the population lives within a 5 meter elevation –Mostly fishermen <30 minutes to evacuate Inundation distance ~2 km Population Density and Distribution

44. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE One of 6 cities designated to undertake earthquake and tsunami risk reduction after 2004 Early warning systems Planning evacuation routes Education and evacuation drills –“duck, cover, hold” –tsunami evacuation Over 50,000 people will still be unable to evacuate within < 30 minute tsunami arrival time Preparedness Efforts in Padang

45. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Evacuation Structures | Examples Refuge Structures: Designed to rise above the expected tsunami inundation level, and withstand the expected earthquake and tsunami forces; provides vertical evacuation Bridges: Designed to be earthquake-resistant and serve as element of horizontal evacuation

46. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Evacuation Structures | Existing Buildings Regulation requires all buildings > 2 stories to serve as evacuation site during tsunami Existing Building Surveys –5 different organizations –Based on location and capacity, suitability not thoroughly considered –Seismic deficiencies not considered Buildings used as sites in evacuation simulations

47. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Tsunami Evacuation Most people evacuated after shaking Problems with evacuation plan –sometimes slow to initiate –traffic jams (1-2 hrs) –lack of information and coordination Little evidence of vertical evacuation Roads and bridges generally intact Performance of evacuation buildings –1/3 collapsed or heavily damaged –3/4 had sufficient damage to be closed

48. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE High Ground Coastline Evacuation Structures | Bridges

49. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Evacuation Structures | LBA LIA 4 story language school First 2 stories collapsed July 2009October 2009

50. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Evacuation Structures | STBA Prayoga 4 story junior college Complete collapse July 2009October 2009

51. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Evacuation Structures | Plasa Andalas 4 story mall Partial collapse on 4 th floor and fire July 2009October 2009

52. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Good Candidates for Evacuation Indonesian Bank Complex Tsunami evacuation –large building –elevated site –terrace @ 20 m –on-site security Moderate EQ damage Evacuation lessons –public awareness –individuals must feel safe & confident

53. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Good Candidates for Evacuation Major mosques in general are good candidates for evacuation –Large prayer area –Redundant structures –Better construction quality –Good accessibility –People tend to go to mosques after disasters ~100 people evacuated to Masjid Taqwa after the earthquake

54. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Observations and Lessons Overview of Damage –Buildings –Bridges and Transportation –Utility Lifelines Deaths and Injuries Resiliency of Padang City Tsunami Evacuation –Tsunami still a threat –Inadequate evacuation capacity –Evacuation structures are crucial Building Code provisions and enforcement Rebuilding Better / Safer?

55. E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Thanks! Questions?