INVESTIGATION ON THE PERFORMANCE OF BUILDINGS WITH STRUCTURAL WALLS - PowerPoint PPT Presentation

INVESTIGATION ON THE PERFORMANCE OF BUILDINGS WITH STRUCTURAL WALLS IN THE TOHOKU, JAPAN, EARTHQUAKE OF 2011 Toshikatsu Ichinose, Nagoya Institute of Technology Santiago Pujol, Purdue University Susumu Takahashi, Nagoya Institute of Technology

observed. damage are investigated. earthquake are discussed.  Severe damage of RC buildings with structural walls were  Three retrofitted RC buildings are picked up and the  The reason of the damage and what happened during the

 Built in 1968  6-story RC building  Retrofitted in 1997 6600 3200 18800 5600 6600 8000 8000 8000 8000 8000 8000 8000 56000 1 st story plan

Observed damage in longitudinal direction

15.0 5.0 5.0 1.0 6.0 10.0 1.5 1.5 10.0 5.0 1.0 Observed damage in longitudinal direction

This frame has large Limit analysis strength. …But, coupling beams deform 5 times as much as walls. Σ a t σ y A B C D

6.0 1.0 5.0 5.0 15.0 1/1410 15 1/910 800 1/620 1975 (mm) 1/790 1/540 1/1360 A B B’ C D Estimated deformation

 Built in 1966  8-story RC building  Retrofitted in 1996 K 6600 J 19200 6000 I 6600 H 3000 8000 8000 8000 8000 8000 8000 8000 3000 56000 7 9 8 10 11 12 13 14 6 th story plan

Observed damage in longitudinal direction

RF 8F 600 7F 280 6F 5F 4F D25 (#8) 430 3F 2F Observed damage in transverse direction

RF 8F 7F 6F 5F 4F outside inside 3F 2F window Observed damage in transverse direction

was serious. Damage in left hand side Observed damage in transverse direction

Reinforcement with carbon fiber

Pushover analysis Large deformation In short beam

Effect of Longitudinal Web Reinforcement Discontinuities on the Drift Capacity of Structural Walls Ying Wang Santiago Pujol Purdue University

Plan View (stories: 1-2) 6.75m 8m

Plan View (stories: 3-9) 6.75m 8m

3.3m

Earthquakes and Strengthening

Miyagi Earthquake 1978 Shiga et al. (1981)

Strengthening in 2001

Tohoku Earthquake 2011

Discontinuity (bottom of third story)

Tohoku Earthquake 2011 0.5 Displacement Response (m) 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 1978NS-2%Damping 0.05 2011NS-2%Damping 0 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5 Period (sec)

Hypothesis Discontinuity ( longitudinal web reinforcement ) Strain Concentration Decrease in drift capacity

Experimental Program 3'-9" 2' 10" 10" Specimens 2,5 and 6 Specimens 1,3 and 4

Experimental Program 10" l be = 2" l be = 2" l w = 6" t w = 2" 1" t be = 4" 2" 1"

Tensile Strain Distribution at a Drift Ratio of 3% 30 25 No Cutoffs Cutoffs 20 Height (in) 15 10 5 0 0.000 0.020 0.040 0.060 0.080 Maximum Tensile Unit Strain

No Cutoffs Cutoffs

Hypothesis Discontinuity ( longitudinal web reinforcement ) Strain Concentration Decrease in drift capacity toughness