Damage of Buildings. Hitoshi Shiohara

Transcription

1 Damage of Buildings by Hitoshi Shiohara Associate Professor, University of Tokyo, PhD, FACI Secretary, Disaster Committee, Architectural Institute of Japan (AIJ) Leader, Reconnaissance Group, Kanto Branch of AIJ 1

2 Road Maps verview Statistics of damaged buildings Performance of ld and New RC Buildings Case study: Nagano-machi apartment complex building in Sendai Beam-column joint : Full Scale Shaking Table Test on E-Defense Concluding remarks 2

3 Iwanuma, Miyagi Source: Mainichi News Paper Direct material damage from the disaster estimates 16.9 trillion yen Building % Civil infrastructure % Agriculture & Fishery % Lifeline % thers % Total % Unit: trillion yen (1 trillion yen = 12.5 B US$) loss due to failure of nucleus four power plant units excluded 3

4 Iwanuma, Miyagi Source: Mainichi News Paper Tsunami : 10 meter high 4

5 Minami Sanriku, Miyagi Source: Mainichi News Paper nly RC buildings remained intact from deadly collapse 5

6 Typical Tsunami Damage to Buildings 0 verturned Koban (in nagawa, RC, two-storied) RC 2 Hotel partially intact (in Miyako, S, six-storied) S 6 Collasped Building (in Rikuzen-takata, RC, one-storied) RC Wood House swept away (in Watari, W) RC Collapsed Seawall (in Yamada, RC) ( RC ) verturned Brick Wall (in Watari, Concrete Block) CB 6

7 Simplified3.1 Water Pressure Formula for Design 第２章 地震 地盤 津波 Earthquake, ground condition, and tsunami qx = ρ g ( ah z ) ä (Tsunami height, inundation height, and inundation depth) ä 3h 6) Building ah 2) inundation depth : h /1103/13a/kaisetsu pdf 62 8) 561km ) m GPS 23 56km2 23 h 2 z 6 4) No m 9) 5) HP 4 a3ρ gh gh /db/tide/suisan/explanation.html 6)

8 Tsunami Resistance of Buildings Reinforce concrete buildings have potential to survive. Tsunami evacuation buildings are necessary for saving the lives who can not relocate quickly to safer place. Simplified water pressure formula for design are evaluated by examining the tsunami survived and collapsed buildings inventory 8

9 Statistics of Damaged Non-residential Buildings Prefecture Number Hokkaido 470 Aomori 1,184 Iwate 1,538 Miyagi 17,315 Fukushima 1,015 Ibaraki 8,449 Tochigi 295 Gunmma 195 Saitama 33 Chiba 708 Tokyo 20 Kanagawa 2 Credit: the National Police Agency Sendai, Miyagi Tsunami damage buildings included Hokkaido (470) Aomori (1184) Iwate (1538) Miyagi (17,315) Fukushima (1,015) Ibaraki (8449) Chiba (708) Tokyo (20) from Wikipedia nagawa, Miyagi 9

10 Statistics of Housing Severely Damaged Prefecture Death & missing Severe Damage Hokkaido 1 0 Aomori Iwate 4,709 20,998 Miyagi 9,194 65,462 Fukushima 1,709 15,897 Ibaraki 24 2,163 Tochigi Gunmma 1 0 Saitama 1 7 Chiba Tokyo 7 11 Kanagawa 4 0 Credit: the Fire Defense Agency Tsunami damage buildings included ( ) : Death toll Hokkaido 0 (1) Aomori 306 (3) Iwate (4709) Miyagi (9194) Fukushima (1709) Ibaraki 2163 (24) Chiba 771 (20) Tokyo 7 (11) Watari, Miyagi from Wikipedia 10

11 Statistics of Damaged Buildings Brief history of RC buildings and seismic codes in Japan The rate of damaged buildings are low but Damage buildings location widely distributed in east Japan 11

12 Revisions of Japanese seismic provisions in codes Tokachi-oki Earthquake 1995 Amendment of BSL Enforcement rder ( Prevention of column shear failure ) 2000 *BSL : Building Standard Law Miyagiken-oki Earthquake Amendment of BSL Enforcement rder ( The shin-taishin, new standard ) 1995 Hyogo-ken Nambu Earthquake ( Effectiveness of the 1981 revision was confirmed ) Act on Promotion of Seismic Retrofitting of Existing Buildings ( To urge building owners to retrofit existing vulnerable buildings ) Amendment of BSL Enforcement rder ( Performance based criteria introduced ) I 1971 II 1981 III Tohoku-chiho Taiheiyo-oki Earthquake 12

13 Inventory Study of RC School Buildings in Miyagi Number of school buildings 35 I II III credit : Maeda et al. legitimate Retrofit not necessary Retrofit done No Retrofit Inventory Senday City & Municipalities in the vicinity of Sendai 546 buildings in total Higashi Matsushima, Miyagi 5 0 Year of construction 13

14 Inventory of School RC Buildings in Miyagi Number of school buildings 35 I II III credit : Maeda et al. Foundation Severe Moderate Minor No damage Damage grade Inventory Senday City & Municipalities in the vicinity of Sendai 546 buildings in total buildings in total Damage due to Tsunami excluded 5 0 Year of construction 14

15 Typical Damage to Structural & Nonstructural Members Shear Failure of RC Captive Column Shear Failure of RC Shear Wall Shear Failure of RC Boundary Beam Failure of RC Stair Anchorage Fallen non-structural Concrete Brick Fallen non-structural Ceiling 15

16 Performance of ld and New Buildings Inventory Study of RC School Buildings were made Similar pattern of damage compared to past building damaged observed shear failure structural members non-structural elements Effectiveness of seismic retrofit is proved 16

17 Case Study: Nagano-machi Apartment Complex 17

18 Nagano-machi Apartment Complex 18

19 Nagano-machi Dwelling Building Complex in Sendai City RC/SRC 9 floors. Completed in 1969 Survived major earthquakes in 1978, 2003 and Seismic vulnerability was assessed in 2010 No rehabilitation yet Fc 210 & 180 Grade SD35 rebars to be demolished 19

20 Elevation of X1 frame in transverse direction steel shape in concrete III III III I see Fig. 7 II I V III V IV III II shear cracks on coupling beams Y 0 Y 1 Y 2 Y 3 Y 4 Y 5 unit in mm 20

21 1st floor plan and damage rate south north west Y 5 II II I IVs II I II Y 4 II III III II I I I I Medical Service Y 3 Entrance II IVs I I Y 2 see Fig. 7 IV Municipal offices III Vs III Damage Grade east Y 1 Y 0 V X 0 IV V II V I III I V II III II II II I X 1 X 2 X 3 X 4 X 5 X 6 X 7 X 8 : no damage I : slight II : minor III : moderate IV : major V : severe 21

22 2nd floor plan and damage rate south north Y 5 I I I I west Y 4 II I I I Y 3 II II Vs I I Municipal offices east Y 2 I I I I Damage Grade Y 1 Y 0 III II I I I III I III X 0 I I I X 1 X 2 X 3 X 4 X 5 X 6 X 7 X 8 : no damage I : slight II : minor III : moderate IV : major V : severe 22

23 3rd floor plan and damage rate Y 5 I I south I I north RC non-structural partition Y 4 west Y 4 II I IIVs IIVs Y 3 Y 3 II II Vs I I Corridor Y 2 east Y 1 Y 0 Y 2 I I I Y 1 III II I IVs IVs I I I I III I I II III X 1 X 2 X 3 XI 4 XI 5 XI 6 X 7 X 8 Damage Grade : no damage I : slight II : minor III : moderate IV : major V : severe X 0 Apartment units X 1 X 2 X 3 X 4 X 5 X 6 X 7 X 8 23

24 Elevation of X1 frame in longitudinal direction steel shape in concrete III III III flexural failure and buckling of rebars at the bottom of column Damage grade : V I see Fig. 7 II I V III V IV III II Y 0 Y 1 Y 2 Y 3 Y 4 Y 5 unit in mm 24

25 Elevation of Y4 frame in longitudinal direction PHRFL 36,150 shear crack on beam-column joint Shear failure of columns Damage grade : V RFL 26,150 9FL 8FL 23,350 20,750 see Fig. 10 7FL 18,150 6FL 15,550 5FL 4FL 12,850 10,150 IVs IVs IVs IVs Latice steel 3FL 7,400 IVs IVs 2FL 4,100 I I II 1FL GL 500 I I I I II III II = X 8 X 7 X 6 X 5 X 4 X 3 X 2 X 1 X 0 Unit in mm 25

26 9FL 8FL 7FL 6FL 5FL Close up 4FL 3FL 2FL 26

27 9FL 8FL 7FL Shear Failure Beam-column joint 6FL Shear Failure of Column 27

28 Detailing : Beam-column Joints unit in mm 4-D19 4-D D19 hoop φ9@ D D22+6-D19 hoop φ9@ D horizontal section of column vertical section of beam horizontal section of column vertical section of beam (a) Beam-column joint at 7F (X 5 -Y 4 ) (b) Beam-column joint at 5F (X 5 -Y 4 ) 28

29 Performance Evaluation of Beam-column Joint floor plan Tributary area of gravity load Wall Column column beam joint column case 1* column case 2* beam case 1 Wall+Column Joint Shear failure Beam Flexural l hinge Column- in kn in kn strengt -to-beam th ratio case 2 Column Joint shear strength margin* 9FL FL FL FL FL

30 Case Study: Nagano-machi Apartment Complex Structural system and the damage rate of structural components Seismic vulnerability assessment Beam-column joint Conclusions 30

31 Beam-column joint: Full Scale Shaking Table Test at E-Defense 1493 E-Defense Shak 31

32 E-Defense test on RC Building in December 2011 X Y 20 m 15 m Figure 2.1 E-Defense shaking table E-Defense 3D Shaking Table Four Storied Wall-Frame RC Structure 32

33 Joint List of Column C1 C2 List of Girder Location End G1 Center End List Locati 4Fl. 3Fl. Section B x D Rebar Hoop Joint Section 500 x D22 2,2-D10@100 2,2-D10@ x D22 2,2-D10@100 2,2-D10@140 RFl. 4Fl. Section B x D Top Bottom Web Stirrup 300 x D22 3-D22 4-D22 3-D22 3-D22 3-D22 4-D10 2-D10@200 RFl. Sectio B x D Top Botto Web Stirru 2Fl. B x D Rebar Hoop Joint Top Section 500 x x D22 10-D22 2,3-D10@100 2,4-D10@100 2,2-D10@140 2,2-D10@140 3Fl. Section B x D Top Bottom Web Stirrup 300 x D22 3-D22 5-D22 3-D22 3-D22 3-D22 4-D10 2-D10@200 4Fl. 3Fl. 2Fl. Sectio B x D Top Botto Web Stirru 1Fl. B x D Rebar Hoop Joint Bottom Section B x D Rebar Hoop Joint 500 x D22 2,3-D10@100 2,2-D10@ x x D22 10-D22 3,4-D10@100 3,4-D10@100 2,2-D10@140 2,2-D10@140 2Fl. Section B x D Top Bottom Web Stirrup 300 x D22 3-D22 6-D22 3-D22 3-D22 3-D22 4-D10 2-D10@200 All List Locati Sectio B x D Top Botto Web Stirru 33

34 Margin of Joint Shear Capacity Joint shear / Nominal joint shear capacity 34

35 Column-to-beam strength ratio Column-to-beam strength ratios 35

36 JMA Kobe 50% 36

37 JMA Kobe 50% 37

38 JMA Kobe 100% 38

39 JMA Kobe 100% 39

40 Beam-column joint: Full Scale Shaking Table Test on E-Defense Nagamachi Dwelling Complex Building Flexural failure of the first story SRC column deficiency of steel lattice not embedded into the foundation which just ends at the first floor level. abrupt change of section caused the damage. Shear failure of lightly reinforced beam-column joints. calculated margin of joint shear strength is 2.0 or more. column-to-beam strength ratio is in the range of 1.26 to vulnerablity of column-to-beam strength ratio between 1.0 and 1.5 are to joint shear failure. problem in failure mode prediction 40

41 Further information : Recommended Resources on Building Damage PREFACE Devastating damage in the Tohoku region of Japan occurred during and after the earthquake off the Pacific coast of Tohoku earthquake on March 11, The report summarizes damage associated with ground failures including landslide and liquefaction as well as non-structural damages such as to equipment and facilities, partitioning walls and ceilings, and functional failures in skyscrapers. Also brief description of the Japanese Seismic Design Code will be provided in the Appendix. A proposed scheme of antitsunami design for buildings is also included. Edited by the Architectural Institute of Japan Preliminary Reconnaissance Report of the 2011 Tohoku-Chiho Taiheiyo-ki Earthquake Geotechnical, Geological and Earthquake Engineering series 7 The only official reconnaissance report of the Architectural Institute of Japan 7 Full of concrete information on building damages in the Tohoku and Kanto regions 7 Mainly consists of field information in the damaged areas without detailed analysis springer.com DUE SEPTEMBER

42 Thank you for your kind attention. 42