1 Building damage by the 2011 off the Pacific coast of Tohoku earthquake and coping activities by NILIM and BRI collaborated with the administration Isao Nishiyama (NILIM), Hiroshi Fukuyama (),(BRI), Yasuo Okuda (BRI), and Izuru Okawa (BRI). NILIM : National Institute for Land & Infrastructure Management BRI :Building Research Institute This material was presented at UJNR ‐ Wind and Seismic Effects held at PWRI on August 29, 2011. 2 1. Outline By Nishiyama, Isao 3 Field Survey Quick Report (in Japanese) was published on May, 2011 and Summary Report (in English) will soon be available. Isao Nishiyama 4 JMA SiSeism ic ItIntens ity & HtlHypocentral RiRegion Tooouhoku eart hqua ke Mw=9.0 (14:46 JST on March 11, 2011) ★ Isao Nishiyama 5 Fie ld SdSurveyed Cities and Towns Tono City Miyako City Yamada Town Kitakami City Otsuchi Town Hiraizumi Town Kamaishi City Ohunato City Kurihara City Rikuzentakata City Kesennuma City Tsunami‐inddduced Minamisanriku Town Ishinomaki City damage Onagawa Town Higashimatsushima City Matsushima Town Shiogama City Shichigahama Town Tagajo City Sendai City Motion‐induced Natori City Iwanuma City damage Watari Town Yamamoto Town Shiroishi Town Nasu Town Fukushima City Fukushima Daiichi Nuclear Nihonmatsu City Yaita City Miharu Town Power Station Koriyama City Shirosato Town Sukagawa City Kasama City Shirakawa City Hitachiota City Chikusei City Hitachi City Shimotsuma City Naka City Hitachinaka City Mito City Koga City Liquefaction‐induced Oarai Town Bando City Omitama City Joso City Hokota City damage of houses Tsuchiura City Kashima City Ryugasaki City Itako City Surveyed Cities and Kamisu City Sakae Town Towns Inashiki City Urayasu City Isao Nishiyama 6 SdSurveyed Items ∗ Motion‐induced damage ∗ Wood houses, steel buildingg,s, reinforced concrete buildings, residential land, non‐structural elements, seismically isolated buildings,…etc. ∗ Tsunami‐induced damage ∗ Wood houses, steel buildings, reinforced concrete buildings. ∗ (Fire‐induced damage...) Isao Nishiyama 7 Damage Sta tis tics (To hok u vs. Kb)Kobe) 60,000 People injured People Death People missing 50,000 People death Tohoku: 15,700 40,000 Kobe: 6,434 30,000 20,000 10,000 0 3/12 3/19 3/26 4/2 4/9 4/16 4/23 4/30 5/7 5/14 5/21 5/28 6/4 6/11 6/18 6/25 7/2 7/9 7/16 7/23 Kobe EQ 500,000 450, 000 Half collapsed (house) 400,000 Total collapsed include washed away (house) 350,000 300,000 250,000 200,000 Total Collapsed Buildings 150,000 Tohoku: 114,000 houses 100,000 Kobe: 186,175 housing units 50,000 0 3/12 3/19 3/26 4/2 4/9 4/16 4/23 4/30 5/7 5/14 5/21 5/28 6/4 6/11 6/18 6/25 7/2 7/9 7/16 7/23 Kobe EQ (housing Isao Nishiyama units) 8 Coping Activities Isao Nishiyama 9 Four IttImportant Issues ∗ Tsunami Damage ∗ Non‐structural Elements Damage, esp. Ceiling ∗ Long‐period, Long‐duration Ground Motion Effects ∗ Liquefaction Damage ∗ (Damper Damage in Seismically Isolated Building) Isao Nishiyama 10 TiTsunami Out of plain deformation, RC AhArahama, WkbWakabayas hi, Sen da i IidInside, ditto ∗ Study on the design of tsunami evacuation buildings, i.e. estimation of tsunami load More than half of the total inundation area was subjected to inundation height of 2m or less. Isao Nishiyama 11 Non‐sttltructural Element s, esp. CiliCeiling Structures Structures Ceiling Braces Clearance Clearance between ceilings Earthquake induced motion Ceiling is contacting to Structural Members Stiffness difference between Earthquake induced ceilings in different levels motion Previous technical advice (MLIT, 2003.10) ∗ Review of previous technical advice (right), and study on practical structural calculation methods Isao Nishiyama 12 Long‐pp,eriod, Long‐duration Ground Motion Pseudo Vel. Resp. Spectrum (h=5%) Disp. Response Spectrum (h=5%) 50 60 00 100001F(NS) 1 01F(NS) 01F(EW) 01F(EW) 01F(UD) 01F(UD) 0 ) m/s) 1 mm cc 10 40 10 5 elocity Response ( cement Response (c VV aa 20 Displ /s/s) Pseudo 1 1(cm 0. 1 1(cm) 0.5 0 0.1 0.5 1 5 10 0510 Period (sec) Period (sec) Pseudo‐velocity Displacement Osaka prefectural government building (Sakishima) ∗ Tentative new proposal by MLIT and NILIM was announced for public comments Dec. 21, 2010. 3 months before Tohoku EQ. ∗ Background information was published in BRI. Isao Nishiyama 13 Liquef acti on Nisshiro, Inashiki, Ibaraki Fukashiba, Kamisu, Ibaraki ∗ Study on possible indication of expected performance w/wo countermeasures for residential houses (from the view of consumer prottitection) Isao Nishiyama 14 (Damper in SiSeism icall y IltdIsolated Bldg. ) ∗ LRB (Lead rubber bearing) ? Fracture of Lead damper Isao Nishiyama 15 CtCountermeasures in CdCodes /Std/Standar ds Building Structural Codes/Standards Committee Draft of Chaired by Tetsuo Kubo, Tokyo University Building Field Survey on the Earthquake on April 21 and 22 Structural First meeting was on June 8, second on August 18 Codes Public comments on Tentativ e WG on Long‐period New Proposal of earthquake ground motion countermeasures for long‐period First meeting was on July 20 motion Collection of information by Secretariat for supportin g using grant‐in‐aid for Committee and WG maintenance and promotion TG on Building Structural Codes of building standards Public and Standards in general 42.Effect of long‐period comments or First meeting on July 26 motion on super high‐rise proposal of buildings building structural 21. Needs and seeds codes from collection private Isao Nishiyama 16 2. Building Damage due to Earthquake Ground Motions By Fukuyama, Hiroshi Damage to buildings caused by seismic motion 17 <Summary> Damage to buildings is not so severe whereas the seismic itintens ities were hihhigh andthd the disas ter areas were ex ten de d to extremely large • Wood Structure：Typical seismic damage was observed • RC Structure, Steel Structure：Significant difference appears between before and after the new seismic design code (1981). Typical seismic damage was observed • NonNon--structuralstructural Elements：Fall of suspended ceilings in largelarge--scalescale spaces, exterior walls, and interior materials were observed • Residential Land：Damage to developed grounds and sloping for residential houses were observed. Severe liquefaction damage occurred in very wide areas. Hiroshi Fukuyama In Kurihara City, City, JMA seismic intensity of VII was recorded, 18 predominant spectrum is observed in short period, i. e. less than 0. 3s. But the power of spectrum in long period is lower than the limit value regulated in Building Standard Law of Japan for seismic design. Building damage was not so significant on the whole even in the areas where seismic intensity of more than VI was recorded 500 築館 KuriharaMYG004 (IJMA=VII) h=0.05 400 仙台 + Building SendaiMYG013 (IJMA=VI ) Standard law of 300 Shiogama塩竈MYG012 (I =VI+) JMA Japan (cm/s) vv 200 (So il type III) pS (Soil type II) 100 0 000.0 050.5 101.0 151.5 202.0 252.5 Pid()Perio303d(.0s ) PseudoPseudo--velocityvelocity response spectrum at some KK--NETNET observe points Hiroshi Fukuyama Typical seismic damage to Wood Structures 19 Damage of houses with store Damage due to (Inclination of 1st story) Bio‐deterioration Damage of Dozo (Japanese traditional wood Collapse of 1st story Collapse of19 2nd story storehouse coated with clay and plaster finish) Hiroshi Fukuyama Typical seismic damage to RC Structures 20 Collapse of soft‐1st story Shear failure of by shear failure of columns non‐structural walls Pullout of anchor bolts of the exposed‐type SRC Shear filfailure of Shear filfailure due to column base link‐beam20 opening of shear wall Hiroshi Fukuyama 21 Typical seismic damage ––RCRC structure (1) • More than 10 local government office buildings designed by the old seismic code suffered from significant structural damage, shear failure of short columns and loss of axial load bearing capacity . These building could not be used as an emergency operation center. • Damage mitigation for functional continuity is strongly required. Kasama City hall building Sukagawa City hall building Hiroshi Fukuyama 22 Typical seismic damage ––RCRC structure (2) • Most of the retrofitted buildings performed well to secure human lives by preventing collapse. • Damage were observed in some retrofitted buildings Hiroshi Fukuyama 23 Typical seismic damage ––RCRC structure (3) Damage to non‐structural walls of residential buildings retrofitted by oil damper Courtesy of Mr. K. Watanabe of U.R. 23 Hiroshi Fukuyama Typical seismic damage to Steel Structures 24 Buckling of brace Rupture of horizontal brace Spalling of concrete at joint コンクリート剥落 Rupture of Buckling of diagonal Dropping of extensive ceiling brace at joint member of latticed materials and exterior finish column 24 materials Hiroshi Fukuyama Typical seismic damage to Residential Land25 Tilted 3 degrees Large‐scale liquefaction and settled or tilted structures Sand boiling and tilting of house FilFailure of htighooting caused LdLand slidin g on the slope Damage of by the ground damage of the developing25 hill retaining wall and house movement Hiroshi Fukuyama Typical damage to Non-Non-structuralstructural Elements26 Cracking and Failure of glass Fall of exterior wall panels spalling of tile Damage and fall of suspended26 ceiling Hiroshi Fukuyama Typical damage to Seismically Isolated Buildings27 Damage to cover‐panels Damage to Peeled off of paint on for fire protection expansion joint U‐shape dampers Lead damper and crack27 on the surface Hiroshi Fukuyama 28 CtCountermeasures Most of the damage classified were observed in the previous earthquakes. Then previous revising of codes (or handbook) are effective for