Full Scale Steel Plate Shear Wall MCEERNCREE Phase II

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					                                              Full Scale Steel Plate Shear Wall:
                                               MCEER/NCREE Phase II Tests
                                                                    Bing Qu, Michel Bruneau
                                            Department of Civil, Structural, and Environmental Engineering, University at Buffalo



ABSTRACT                                                                                           RESULTS
Steel plate shear walls (SPSW), which are allowed to buckle in shear and form a diagonal           Figure 4 and 5 show the hysteretic base shear-drift loops at the first story and the second story
tension field, have been used as the primary lateral force resisting systems in buildings for      under pseudo-dynamic load. Figure 6 and 7 show the hysteretic base shear-drift loops at the
decades. There have been extensive monotonic, cyclic and shaking table tests on SPSW in            first story and the second story under the subsequent cyclic load. The specimen behaved well
the United States, Canada, Japan, Taiwan and United Kingdom and seismic design                     under the simulated earthquakes and reached an ultimate story drift of 2.5%. Cyclic test was
requirements now exist for this system. However, little experimental information exists on the     imposed up to drift of 5% at which point failure occurred in the load transfer mechanism, i.e.
behavior of intermediate beams in SPSW as well as the performance of such beams having             through the concrete slab at top level of the specimen. Some severe plate damage and
reduced beam sections and composite behavior. The work presented here is an experimental           intermediate beam damage also occurred at drifts between 2.5% and 5%. Examples of
investigation of SPSW system with emphasis on seismic adequacy of intermediate beams.              fractures at intermediate beam-column connection and concrete slab are shown in Figure 8
                                                                                                   and Figure 9.
In order to investigate the related issues, the cooperative full scale experimental research on                           5000                                                                                           5000

SPSW MCEER/NCREE project was developed . This poster descries some parts of Phase II                                      4000                                                                                           4000

researches of this project. In phase II, a full scale two-story one-bay steel plate shear wall                            3000                                                                                           3000

specimen was obtained by replacing the web plates of the steel shear wall specimen of Phase                               2000                                                                                           2000




                                                                                                        Base Shear (kN)
I. The new specimen used A36 steel infill plates and reduced beam sections at the beam-




                                                                                                                                                                                                         2F Shear (kN)
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ends like the specimen of Phase I, which would be normal practice in North America. Tests of                                 0                                                                                              0
the specimen were done under pseudo-dynamic and cyclic conditions.                                                        -1000                                                                                          -1000

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BACKGROUND                                                                                                                -3000

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Although, there has been extensive analytical and experimental research, the behavior of
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intermediate beams in SPSW as well as the performance of such beams having reduced                                                -2   -1.5   -1   -0.5      0      0.5       1   1.5   2   2.5   3
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                                                                                                                                                                                                                                 -2    -1.5   -1   -0.5       0        0.5     1   1.5       2   2.5       3
beam sections and composite behavior have not been thoroughly studied.                                                                                           Drift (% )                                                                                       Drift (% )


Research on SPSW has produced useful models for design and analysis of such kind of                Fig. 4 1F Hysteresis in Pseudo-dynamic Test                                                         Fig. 5 2F Hysteresis in Pseudo-dynamic Test
lateral load resisting system. Some of these have ended up in the newest version of the                                   5000                                                                                           5000

Canadian Institute of Steel Construction Specifications (CSA, 2003) and AISC Seismic                                      4000                                                                                           4000

Provision for Steel Structural Buildings (2005). Berman and Bruneau (2003), Vian and                                      3000                                                                                           3000
Bruneau (2005) and Lopez Garcia and Bruneau (2005) have respectively proposed a simple                                    2000                                                                                           2000
plastic analysis method to estimate the lateral load bearing capacity, an analytical model for
                                                                                                     Base Shear (kN)




                                                                                                                                                                                                      2F Shear (kN)
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the SPSW with perforated or cutout corner panel and top/bottom anchor beams design
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methods.
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OBJECTIVES
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The objectives of this research are:                                                                                      -4000                                                                                          -4000

• To investigate whether it is possible to replace the steel panel in SPSW after a severe                                 -5000                                                                                          -5000

  earthquake.                                                                                                                     -4    -3    -2    -1       0
                                                                                                                                                          Drift (% )
                                                                                                                                                                       1      2    3    4    5    6                              -4    -3     -2   -1        0         1       2   3     4       5     6
                                                                                                                                                                                                                                                          Drift (% )
• To observe how the repaired SPSW would behave in a second earthquake after the
  replacement of steel plate panel in light of the residual capacity of frame of the steel plate                          Fig. 6 1F Hysteresis in Cyclic Test                                                                         Fig. 7 2F Hysteresis in Cyclic Test
  shear walls.
• To study how the intermediate beam would behave as part of this system.
• To investigate the residual lateral load bearing capacity of the specimen after a severe
  earthquake.
• To access the hysteretic properties of this specimen.


METHODS
The experiments were conducted in the NCREE laboratory. The specimen was tested under
pseudo-dynamic load to an earthquake having a 2% in 50 years probability of occurrence
(Chi_Chi_CTU082EW-2/50 PGA=0.67g) and subsequently cyclic load to failure. Figure 1,
Figure 2 and Figure 3 show some information related to the test set up.


                                                                                                   Fig. 7 Intermediate-beam-column Connection 5% Drift                                                                                   Fig. 8 Slab at Top Level 5% Drift

                                                                                                   CONCLUSIONS
                                                                                                   It was shown that the specimen obtained by replacing the web plates of the steel shear wall
                                                                                                   specimen of Phase I achieved satisfactory ductility and energy dissipation in the pseudo-
                                                                                                   dynamic test and succeeding cyclic test. RBS detailing in top/bottom anchor beam behaved
                                                                                                   well during the whole drift history. RBS detailing in intermediate beam performed well at low
                                                                                                   drifts (0%-2.5%) and fractures at the intermediate beam-column connections developed at high
                                                                                                   drifts (2.5%-5%).

                                                                                                   ACKNOWLEDGEMENTS
                                                                                                   Program area: 2
                                                                                                   Task number: 9.2.2
   Fig. 1 Test Setup               Fig. 2 In Plane Actuators          Fig. 3 Out Plane Actuators   Principal investigator and/or faculty advisor: Dr. Michel Bruneau
                                                                                                   Acknowledgements: This work was supported in whole by the Earthquake Engineering
The thicknesses of the infill panel were 3.2 mm at first story and 2.3 mm at the second story.     Research Centers Program of the National Science Foundation under Award Number ECC-
The specimen was connected to the strong floor of NCREE using fixed ends at column bases.          9701471 to the Multidisciplinary Center for Earthquake Engineering Research.




                                   MULTIDISCIPLINARY CENTER FOR EARTHQUAKE
                                            ENGINEERING RESEARCH

				
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