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

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 (Rukos) Residential Homes Primarily Reinforced Concrete Frames with Brick Infill Walls URM, Confined Masonry, Wood Few Steel Moment Frames

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

Building Damage and Collapse Story Collapse Complete Collapse

Brick Masonry Infill Wall & NS Damage Building Damage and Collapse

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)

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

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) 700 students attend school 200 students at time of EQ EQ Drills teach duck and cover Students ran out of building No student victims Partial Collapse in Classroom

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

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

E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Provincial Planning Building 3 story, st 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

E E R I TECHNICAL BRIEFING ON SEPTEMBER 30, 2009 PADANG, INDONESIA EARTHQUAKE Provincial Planning Building

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

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

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

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 200 fatalities in the hotel (est.)

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 and PR moment connections led to progressive collapse

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

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

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

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

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 Random performance Some collapse some minor damage No comprehensive plan check

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

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

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

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

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/home shops Challenge to implement these in the re- construction effort