Steel Plate Shear Wall Design - SEAoT

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Aug 12, 2012 ... Opinions presented are those of the author. Steel Plate Shear Walls. (SPSW). Example of. Implementation. (USA). CourtesyTony Harasimowicz ...
8/12/2012

STEEL PLATE SHEAR WALLS (SPSW), TEBF, CFST, SF, AND OTHER SHORT STORIES Michel Bruneau, Ph.D., P.Eng Professor Department of Civil, Structural, and Environmental Engineering

Introduction ƒ Focus on SPSW (incl. P-SPSW, SC-SPSW), CFST, CFDST (and maybe a bit more) ƒ Broad overview (References provided in NASCC paper for more in-depth study of specific topics) ƒ Additional technical information can also be found at www.michelbruneau.com and in “Ductile Design of Steel Structures, 2nd Edition” (Bruneau et al. 2011)*.

* Subliminal message: This book will give you ultimate reading pleasure –buy 100 copies now!

Acknowledgments - 1

Acknowledgments - 2

ƒ Graduate students:

ƒ Sponsors:

ƒ Samer El-Bahey (Stevenson & Associates)

ƒ National Science Foundation (EERC and NEES

Programs)

ƒ Jeffrey Berman (University of Washington, Seattle) ƒ Daniel Dowden (Ph.D. Candidate, University at Buffalo)

ƒ New York State

ƒ Pierre Fouche (Ph.D. Candidate, University at Buffalo)

ƒ Federal Highway Administration,

ƒ Shuichi Fujikura (ARUP)

ƒ American Institute of Steel Construction

ƒ Michael Pollino (Case Western Reserve University)

ƒ Engineer Research and Development Center (ERDC) of

the U.S. Army Corps of Engineers

ƒ Ronny Purba (Ph.D. Candidate, University at Buffalo)

ƒ MCEER, NCREE, Star Seismic, and Corus Steel.

ƒ Bing Qu (California Polytechnic State University) ƒ Ramiro Vargas (Technological University of Panama) ƒ Darren Vian (Parsons Brinkerhoff)

„

ƒ See others at www.michelbruneau.com This support is sincerely appreciated. Opinions presented are those of the author.

Example of Implementation (USA)

Steel Plate Shear Walls (SPSW) ( ) Infill (Web) Column (VBE) Beam (HBE)

CourtesyTony Harasimowicz, KPFF, Oregon

1

8/12/2012

Examples of Implementation (USA) „ „

Examples of Implementation (USA)

LA Live 56 stories

Courtesy Lee Decker – Herrick Corporation, Stockton, CA

Analogy to TensionTension-only Braced Frame „ „

Flat bar brace Very large brace slenderness l d (e.g. ( in i excess of 200)

Courtesy of GFDS Engineers, San Francisco, and Matthew Eatherton, Virginia Tech

„

„

V „

„

Analogy to TensionTension-only Braced Frame „

„

Steps to “transform” into a SPSW 1)) Replace p braces byy infill plate (like adding braces)

Analogy to TensionTension-only Braced Frame „

V

„

„

Anchor Beam

Pinched hysteretic curves Increasing drift to dissipate further hysteretic energy Not permitted by AISC Seismic Provisions Permitted by CSA-S16 within specific limits of application

Steps to “transform” into a SPSW 1)) Replace p braces byy infill plate (like adding braces) 2) For best seismic performance, fully welded beam-column connections

V

2

8/12/2012

Berman/Bruneau June 12 2002 Test End--Result End „

„

Cyclic (Seismic) behavior of SPSW Sum of z

z

V

Fuller hysteresis provided by moment connections Stiffness and redundancy provided by infill plate

L/tw = 3740 h/L = 0.5 (centerline dimensions)

Example of Structural Fuse

600

Base Shear (kN)

400 200 0

-200 -400

Specimen F2 Boundary Frame

-600 600

-3

-2

-1

0 Drift (%)

1

2

3

-3

-2

-1

0 Drift (%)

1

2

3

Base Shear (kN)

400 200 0

-200 -400 -600

Forces from Diagonal Tension Field

ωV = σ t cos2(α) ωH = σ t sin(α) cos(α) = ½ σ t sin(2α) FH = ωH L = ½ σ L t sin(2α)

Knowing L, σy, and α, Can calculate needed thickness (t)

σ ·t

Brace and Strip Models α

PANEL TENSION FIELD STRESS ACROSS UNIT

UNIT PANEL WIDTH ALONG DIAGONAL

V =P··cos α

DIAGONAL WIDTH,

α

P = σ · t · ds H =P·sin α

σ

θ

RESULTANT TENSION FIELD FORCE, P AND COMPONENTS

tw i =

ds

α

ωV =V /dx

SPSW WEB PLATE

ωH =H /dx dx

UNIT

LENGTH

ALONG BEAM

HORIZONTAL, ωH, AND VERTICAL, ωV, DISTRIBUTED LOADING

SPSW HBE

2 Ai sin θi sin 2 θi L sin 2 2 αi hs

hs

L

Equivalent Brace Model (Optional)

L

Strip Model

3

8/12/2012

Strip Model „

„

Strips models in retrofit project using steel plate shear walls

Developed by Thorburn, Kulak, and Montgomery (1983), refined by Timler and Kulak (1983)) V ifi d experimentally Verified i t ll by b z z z

Elgaaly et al. (1993) Driver et al. (1997) Many others Courtesy of Jay Love, Degenkolb Engineers

AISC Guide Design of SPSW (Sabelli and Bruneau 2006 2006))

Recent Observations on SPSW (Bruneau et al. 2011) „

„ „ „ „

Review of implementations to date Review of research results Design requirements and process Design examples z z

„

Region of moderate seismicity Region of high seismicity

Other design considerations (openings, etc.)

Capacity design from Plastic Analysis z

Demands on VBEs

z

Demands on HBEs



 

„ „

Flexibility Factor Factor’ss purpose HBE in-span yielding RBS connections in HBEs

P-SPSW (reduced demands) Repair and drift demands

Plastic Analysis Approach „ „

„

Yielding strips Plastic Hinges

Used to develop Free Body Diagrams of VBEs and HBEs

For design strength, neglect plastic hinges 4⋅M p 1 contribution V = 2 ⋅ Fy ⋅ t ⋅ L ⋅ sin 2α + h

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Capacity Design of VBE

Capacity Design of VBE

Flexibility Limit Issue

Importance of Capacity Design

Lubell et al. (2000) observed poor behavior of some SPSWs (pull-in of columns) Others suggested flexibility limit desirable to prevent slender VBEs

„

„

SPSW-4 UBC Test (Lubell et al. 2000)

SPSW-2 UBC Test (Lubell et al. 2000)

Flexibility Limit (cont’d) „

Plate girder analogy

„

Flexibility Limit (cont’d)

Flexibility factor o

ηo o

Steel Plate Shear Wall

Plate Girder

(ηu −ηo )max = where

ωt = 0.7hsi 4

twi 2Ic L

δ

ηu hs

V

Flange can be modeled as a continuous beam on elastic foundation ⎛ ⎛ω sin ⎜ t εgL ⎜ ⎝ 2 ⎜1 − sin 2 α ⎜ ⎛ ωt ⎜ sin ⎜ 2 ⎝ ⎝

⎞ ⎛ ωt ⎞ ⎛ ωt ⎞ ⎛ ωt ⎟ cosh ⎜ 2 ⎟ + cos ⎜ 2 ⎟ sinh ⎜ 2 ⎠ ⎝ ⎠ ⎝ ⎠ ⎝ ⎞ ⎛ ωt ⎞ ⎛ ωt ⎞ ⎛ ωt ⎟ cos ⎜ 2 ⎟ + sinh ⎜ 2 ⎟ cosh ⎜ 2 ⎠ ⎝ ⎠ ⎝ ⎠ ⎝

⎞⎞ ⎟⎟ ⎠⎟ ⎞⎟ ⎟⎟ ⎠⎠

Increase in streess

Infill Panel

I-Beam Plate Girder

Empirically based flexibility limit:

ωt = 0.7hsi 4

0.9

x

xu

Flange

ωt ≤ 2.5

1.0

L

u

ω t = 3.35

Other specimens that behaved well:

α

Stiffner

Infill Panel

UBC SPSW-2 and SPSW-4:

0.8 07 0.7

twi ≤ 2.5 2I c L

Solving

0.6 0.5

0.00307twi hsi 4 L Introduced in the CAN/CSA S16-01 and 2005 AISC Seismic Provisions Ic ≥

0.4 0.3 0.2

20%

0.1 0.0 0

0.5

1

1.5

2

ωt

2.5

3

3.5

4

5

8/12/2012

Column Design Issues (cont’d)

Flexibility Limit (cont’d) „

Prevention of In-Plane Shear Yielding

„

SPSWs tested by Tsai and Lee (2007) exceeded flexibility limit, yet performed comparably to SPSWs meeting limit

Evaluation of previous specimens

z

Case

Specimen Number of identification stories

Researcher

ωt

Vn

Vsap 2000

Vu − design

(kN)

(kN)

(kN)

Shear Yielding

(i) single-story specimen 1Driver Lubell al (2000)ω =1.73SPSW2 Park et al,et1997, t

2

Berman and Bruneau (2005)

F2

3.35 et1 al, 2007

1 1.01 ωt=1.58

75

108

113

932

259

261

Yes No

766

1361

1458

Yes

(ii) multi-story specimen-a 3

Driver et al (1998)

-b

4

1 73 1.73

4

Park et al (2007)

SC2T

3

1.24

Park et al, 2007, ωt=1.62 676

1011

5

SC4T

3

1.44

999

984

1273

No

6

SC6T

3

1.58

999

1218

1469

Yes

7

WC4T

3

1.62

560

920

1210

Yes

8

WC6T

3

1.77

560

1151

1461

Yes

9

Qu and Bruneau (2007)

b

-

2

1.95 2881

1591

2341

No

10

Tsai and Lee (2007)

SPSW N

2

2.53

968

776

955

No

SPSW S

2

3.01

752

675

705

No

11 a b

SPSW S (ωt=3.01>2.5)

SPSW N (ωt=2.53>2.5)

999

For multi-story specimens, VBEs at the first story are evaluated. Not applicable. Lubell et al, 2000, ωt=3.35

1.2

Excessive flexibility example

1F Drift = 0.2%

σ / fy

1.0

σ / fy

0.8 0.6 0.4 0.2

8.0E+005

0.0 1.2

6.0E+005

1F Drift = 0.3%

1.0

4.0E+005

Specimen: Two-story SPSW (SPSW S) Flexibility factor: ωt=3.01 =3 01 Researchers: Tsai and Lee (2007)

2 0E+005 2.0E+005 0.0E+000

σ / fy

Base Shear (N)

1.0E+006

0.8 0.6 0.4 0.2 0.0 1.2

3.5E+006

o lα

x

1F Drift = 0.6%

1.0

3.0E+006 2.5E+006

0.8 0.6 0.4 0.2

2.0E+006

0.0 1.2

1.5E+006

1F Drift = 2.0%

1.0

Specimen: Four-story SPSW Flexibility factor: ωt=1.73 Researcher: Driver (1997)

1.0E+006

0.8 0.6

Lee and Tsai (2008)

0.4

Driver (1997)

0.2

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 1F Drift (%)

0.0 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0

x/lα

HBE Moment Diagram

SPSW

2.0 ωybi+1

Compression ω strut between columns Resultant forces from yielding (x) of strips

fish plate

web of intermediate beam

flange of intermediate beam

d

(B)

xbi

ωybi L V

+

V

V

-

V

ωybi-ωybi+1

o

Vv

κ=0.0 κ=0.5 κ=1.0 κ=1.5 κ=2.0 Maximum

1.5

ωxbi+1

„

0.4

1.2

0.0E+000

„

0.6

0.0

1.2E+006

5.0E+005

HBE FBD

0.8

0.2

σ / fy

„

Tension Fields

σ / fy

„

Theoretically, with infinitely elastic beam/columns, could purposely assign high L/h ratio and low stiffness to the boundary elements (Bruneau and Bhagwadar 2002) Truss members 1 to 8 in compression as a result of beam and column deflections induced by the other strips in tension – entire tension field is taken byy the last four truss members. Behavior even worse if bottom beam free to bend. This extreme (not practical) example nonetheless illustrates how non-uniform yielding can occur

Base Shear (N)

„

1F Drift = 0.1%

1.0

+

(ωybi+ωybi+1)(d+2hf )/2

Normalized Moment:: M(x) / (ωL2/8)

„

No

1.0 0.5

Optional Alternative: RBS at HBE ends In-Span HBE Hinging

0.0 -0.5 -1.0 -1.5

o

-2.0 V h(x )

-

0

0.1

0.2

0.3 0.4 0.5 0.6 0.7 Fraction of span from left support

0.8

0.9

1

Design for wL2/4

6

8/12/2012

Case Study: Design Outputs W16x36

W18x76

(0.88)

(0.99)

Monotonic Pushover Sway and Beam Combined Mechanism L1θ / L2 + θ

L1θ / L2 + θ

ns

∑V H

W16x89 (0.98)

tplate = 0.036 in S = 19.69 in Astrip = 0.72 in2

(0.98)

W16x89

W16x40 (0.96)

(0.96)

W16x40

10 ft

tplate = 0.036 in S = 19.69 in Astrip = 0.72 in2

L2

L1

Δi+2 Vi+2

i =1

i

i

⎛ Lp ⎞ ⎟ =2⎜ ⎜ ⎟ ⎝ L p − L1 ⎠

ns

∑M i =0

pbi

Plastic Hinge on the HBEs Δi+1 ns ns 1 1 + ∑ Fyp L p (t wi − t wi +1 ) sin (2α ) H i − ∑ Fyp t wi L1 sin (2α ) H i i =1 2 i =1 2

x76 W18x (0.99 9)

Vi+1

tplate = 0.059 in S = 19.69 in Astrip = 1.17 in2

(0.99 9)

tplate = 0.059 in S = 19.69 in Astrip = 1.17 in2

x76 W18x

W14x61 (0.99) x50 W18x (0.91 1)

(0.91 1)

10 ft

W18x x50

W12x22 (0.98)

ωb Hi+2

ωc

Horizontal component of the strip yield forces

(0.95) tplate = 0.072 in S = 19.69 in Astrip = 1.42 in2

(0.96)

tplate = 0.072 in S = 19.69 in Astrip = 1.42 in2

W24x62 (0.91)

W24x117 (0.98)

20 ft

20 ft

Hi+1

θ

α

L2

L1

L1 ns L + ∑ Fyp (t wi L2 − t wi +1 L p ) cos 2 α 1 2 i =1 2

Vertical component of the strip yield forces

Hi

Plastic Hinge

SPSW-CD

SPSW-ID

+ Fyp t w1 L2 cos 2 α

Vi

W24x146 (0.96)

(0.92) W24x146

W12x45

W24x62 (0.99)

10 ft

W24x62 (0.99)

Δi

W12x19

Strips remained elastic

Lp

Case Study: Strength per this plastic mechanism is 13% less than per sway mechanism

Design HBEs for wL2/4

Cyclic Pushover Analysis

Cyclic Pushover Analysis

• Monotonic: in-span plastic hinge + significant HBE vertical deformation • Cyclic: to investigate whether phenomenon observed in monotonic analysis may lead to progressively increasing deformations 4%

10.8

3%

7.2

2%

3.6

1%

0

0%

-3.6

-1%

-7.2

-2%

Vertical Displac cement (in) .

14.4

Lateral Drift (%)

Top Floor Displacement, Δ (in)

• Loading history:

-4%

-3%

2

3

4 Number of Cycles, N

5

Æ Significant accumulation of plastic incremental deformation on SPSW-ID

• Maximum Rotations: SPSW-ID = 0.062 radians SPSW-CD = 0.032 radians

SPSW-CD

-2.5

SPSW-ID

-3.0 10.8

14.4

Plastic Analysis Approach

SPSW-ID

„

0.0

„

-1.0

HBE2

Yielding strips Plastic Hinges

1.0 SPSW-CD

„

M/M p

0.5 0.0 -0.5

deserve more attention in future research

-7.2 -3.6 0 3.6 7.2 Lateral Displacement (in)

HBE3 Vertical Displacements

6

-0.5

• AISC 2005 Seismic Specifications: Ordinary-type connections be used in SPSW

ÆTime history analyses show same behavior, with vertical displacements increasing with severity of ground excitation level

0.5 M/M p

• Curves bias toward one direction

1.0

4%

-2.0

Cyclic Pushover Analysis • Comparing rotation demands at beam to column connection

3%

-1.5 15

-4% 1

2%

-1.0

-3%

-14.4

Lateral Drift -1% 0% 1%

-0.5

-14.4 -10.8 -10.8

-2%

0.0

-1.0 -2.5

HBE2

-2.0

-1.5

-1.0

-0.5

0.0

0.5

1.0

θ / θ 0.03

Normalized Moment Rotation (θ/0.03)

For design strength, neglect plastic hinges 4⋅M p 1 contribution V = 2 ⋅ Fy ⋅ t ⋅ L ⋅ sin 2α + h

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8/12/2012

Single Story SPSW Example

Plastic Analysis Approach „

Design

Interpretation #2: Lateral load Vu=

α h

„

Interpretation #1: Lateral load Vu=

L

Force assigned to infill panel

V =

4⋅M p 1 ⋅ Fy ⋅ t ⋅ L ⋅ sin 2α + 2 h

κ ⋅Vdesign =

Single Story SPSW Example 2.25 2.00

50000 Overstrength from capacity design

40000

1.50

Weighht (lb)

Vplastic/ Vd design

1.75

Case Study

α = 45D β = 1.0

L/h=0.8 L/h=1.00 L/h=1.5 L/h=2 L/h=2.5

1 f yp t w Lh sin ( 2α ) 2

1 25 1.25

30000 20000

1.00

Balance point

0.75



κ balance = ⎢1 + ⎢⎣

0.50

⎤ 1L β ⋅ ⎥ 2 h 1 + 1 − β 2 ⎥⎦

10000

−1

0 AISC

Design force to be assigned to boundary moment frame

0.25

PROPOSED Panel HBE

VBE

75% Total

40%

0.00 0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

κ

Quantifying Performance

Seismic Performance Factors Parameter

• Time history analyses of SPSWs designed with various k value revealed different drift response • Need to rigorously quantify significance in terms of seismic performance • FEMA P695 procedure is a useful tool for that purpose

SW320

SW320K

Reference

1. Design Stage R

7

7

ATC63 Design 3-Story SPSW Big Size 100%.xls

176

176

ATC63 Design 3-Story SPSW Big Size 49%.xls

Vmax

495

226

δy,eff

1.80

1.8

δu

8.86

8.64

Ω = Vmax/Vdesign

2.81

1.29

μT = δu/δy,eff

4.92

4.80

SCT

3.60

2.29

IDA Curve for SW320 Sa PDGravity+Leaning.xls

SMT

1.50

1.50

IDA Curve for SW320K Sa PDGravity+Leaning.xls

CMR = SCT/SMT

2.40

1.53

Vdesign 2. Nonlinear Static (Pushover) Analysis

Pushover Curve for SW320 and SW320K.xls Included SH = 2%, Ωd = 1.2 and φ = 0.9

3. Incremental Dynamic Analysis (IDA)

8

8/12/2012

Typical Archetype Model

Component Degradation Model

OPENSEES Model:

M

• Fiber Hinges on HBE and VBE ends

My

P

Mcap SH = 2%

Py

EI

• Axial Hinges on Strips

EA

-θy θy Symmetri c

• Gravity loads applied on SPSW according to its tributary area.

0.081

0.039 0.064

θ

δy No Compression Strength

-My

(a) Boundary Elements

• Remaining loads applied on Leaning columns

Pcap SH = 2%

9.0δy 10.7δ

δ

y

0.015 0.018 (Axial Strain)

(b) Strips

Failure mode developed based on 33 previously tested SPSW specimens Degradation model verified on 1 to 4 story SPSW specimens

Dual Strip Model

P-Δ Leaning Column

Incremental Dynamic Analysis (IDA) Results - Sa

Seismic Performance Factors

SW0320

Parameter

SW320

SW320K

Reference

1

1. Design Stage R

Probability off Collapse

0.8

SW0320K

7

7

ATC63 Design 3-Story SPSW Big Size 100%.xls

176

176

ATC63 Design 3-Story SPSW Big Size 49%.xls

Vmax

495

226

δy,eff

Vdesign 2. Nonlinear Static (Pushover) Analysis

0.6

1.80

1.8

δu

8.86

8.64

SW320 Lognormal SW320

Ω = Vmax/Vdesign

2.81

1.29

SW320K Lognormal SW320K

μT = δu/δy,eff

4.92

4.80

SCT

3.60

2.29

IDA Curve for SW320 Sa PDGravity+Leaning.xls

SMT

1.50

1.50

IDA Curve for SW320K Sa PDGravity+Leaning.xls

CMR = SCT/SMT

2.40

1.53

0.4

0.2

0 0

5 Spectral Acceleration, ST (Tn = 0.36 Sec.), g

Seismic Performance Factors, Cont.

10

Pushover Curve for SW320 and SW320K.xls Included SH = 2%, Ωd = 1.2 and φ = 0.9

3. Incremental Dynamic Analysis (IDA)

Fragility Curve: DM (Inter(Inter-story Drift) for SW320 1

Parameter

SW320

SW320K

Reference

4. Performance Evaluation 0.36

0.36

SDC

Dmax

Dmax

FEMA P695 (ATC63) Table 5-1

SSF (T, μT)

1.25

1.25

FEMA P695 (ATC63) Eq. 5-5 FEMA P695 (ATC63) Table 7-1b

1.91

ACMR = SSF (T, μT) x CMR

3.00

βRTR

0.4

0.4

FEMA P695 (ATC63) Section 7.3.1

βDR

0.2

0.2

FEMA P695 (ATC63) Table 3-1: (B - Good)

βTD

0.35

0.35

FEMA P695 (ATC63) Table 3-2: (C - Fair) FEMA P695 (ATC63) Table 5-3: (B - Good)

βMDL

0.2

0.2

βtot = sqrt (βRTR + βDR + βTD + βMDL )

0.60

0.60

ACMR20% (βtot)

1.66

1.66

FEMA P695 (ATC63) Table 7-3

ACMR10% (βtot)

2.16

2.16

FEMA P695 (ATC63) Table 7-3

Statusi

Pass

Pass

FEMA P695 (ATC63) Eq. 7-6

StatusPG

Pass

2

2

2

2

0.8 Probability off Exceedance

T

0.6 DM: 1% Drift DM: 2% Drift DM: 3% Drift

0.4

DM: 4% Drift DM: 5% Drift DM: 6% Drift

0.2

DM: 7% Drift

NOT Pass FEMA P695 (ATC63) Eq. 7-7

DM: Collapse Point

5. Final Results R

7

Try Again

0

Try Again

Design Level Sa = 1.5g

Ω

2.8

μT

4.9

Try Again

7

Try Again

Cd = R

0

2

4

6

8

10

Spectral Acceleration, S T (Tn = 0.36 Sec.), g

9

8/12/2012

Fragility Curve: DM (Inter(Inter-story Drift) for SW320K 1

Perforated Steel Plate Shear Walls (P (P--SPSW)

Probability off Exceedance

0.8

0.6

DM: Drift 1%

(to reduce tonnage of steel in low low--rise SPSWs)

DM: Drift 2% DM: Drift 3% 0.4

DM: Drift 4% DM: Drift 5% DM: Drift 6%

0.2

DM: Drift 7% DM: Collapse Point 0 0 Design Level Sa = 1.5g

2

4

6

8

10

Spectral Acceleration, ST (Tn = 0.36 Sec.), g

Infill Overstrength „

„

Available infill plate material might be thicker or stronger than required by design. Several solution to alleviate this concern z z z

Light-gauge cold-rolled steel Low Yield Steel (LYS) steel Perforated Steel Plate Shear Wall

Perforated Wall Concept 4

3

2

1

A

Specimen P at 3.0% Drift

B

C

D

E

F

Perforated Layout, Cont.

Sdiag

θ

“Typical” diagonal strip

10

8/12/2012

Typical Perforated Strip ((Vian Vian 2005)

Typical Strip Analysis Results (ST1) At monitored strain emax = 20%, D = 100 mm (D/S (D/Sdiag = 0.25)

Sdiag = 400 mm

2δ ABAQUS S4 “Quadrant” Model D (a) Strip Mesh and Deformed Shape (Deformation Scale Factor = 4)

L = 2000 mm

½L

δ (b) Maximum In-Plane Principal Stress Contours

t = 5 mm not actual mesh

D = variable

Sdiag

½ Sdiag

(c) Maximum In-Plane Principal Strain Contours

FLTB Model

FLTB Model: Typical Panel Results At monitored strain εmax = 20%, D = 200 mm (D/ (D/S Sdiag = 0.471)

5.0 Strip emax = 20% Strip emax = 15% Strip emax = 10% Strip emax = 5% Strip emax = 1%

Total Uniform Strrip Elongation, ε un (%)

4.5 4.0 3.5

Panel emax = 20% Panel emax = 15% Panel emax = 10% Panel emax = 5% Panel emax = 1%

3.0 2.5 2.0 1.5 1.0 0.5 0.0 0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

Perforation Ratio, D/S diag

Maximum In-Plane Principal Strain Contours

Shear Strength vs. Frame Drift 3000

Infill Shear Strength: RF Model 0.9 0.8

2000 1500 1000 500

51.5%

0.7

emax = 20% emax = 15% emax = 10% emax = 5% emax = 1% Solid D050 (D/Sdiag = 0.12) D100 (D/Sdiag = 0.24) D150 (D/Sdiag = 0.35) D200 (D/Sdiag = 0.47) D250 (D/Sdiag = 0.59) D300 (D/Sdiag = 0.71) Bare

Vyp.perf / V yp

Total Shear Sttrength, Vy (kN)

1.0

2500

0.6 0.5 0.4 0.3

⎡ D ⎤ ⋅ V yp V yp. perf = ⎢1 − α Sdiag ⎥⎦ ⎣

Predicted (Eq. 4.3) γ = 5% γ = 4% γ = 3% γ = 2% γ = 1% Linear Reg.

0.2 0.1

correction factor:

0.0

0

0.0

0.0

1.0

2.0

3.0 Frame Drift, γ

4.0

5.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

α = 0.7

1.0

D/S diag

11

8/12/2012

Implementation of P P--SPSW Replaceability of Web Plate in SPSW

Courtesy of Robert Tremblay, Ecole Polytechnique, et Eric Lachapelle, Lainco Inc, Montreal

Experimental Program „

„ „

„

Phase I: Pseudo-dynamic load to an earthquake having a 2% in 50 years probability of occurrence. (Chi Chi CTU082EW--2╱50 PGA=0.67g) (Chi_Chi_CTU082EW--2╱50 PGA=0 67g) Cut-out and replace webs at both levels Phase II: Repeat of pseudo-dynamic load to an earthquake having a 2% in 50 years probability of occurrence. Subsequently cyclic load to failure.

Pseudo--dynamic Test (cont’d) Pseudo

Web replacement „

Buckled web plate from first pseudodynamic test cut out and new web plate welded in place

Pseudo--dynamic Test (cont’d) Pseudo

1st story

2nd story

Specimen after the maximum peak drifts of 2.6% at lower story and 2.3% at upper story in pseudo-dynamic test.

12

8/12/2012

Subsequently Cyclic Test

Subsequently Cyclic Test (cont’d) „

Severe plate damage and intermediate beam damage also occurred at drifts between 2.5% and 5%

2nd story after interstory drift of 5% 1st Story after interstory drift of 5%

Self-Centering SPSW Self-Centering Self(Resilient) SPSWs (SC--SPSWs) (SC

Concept: Replace rigid HBE to VBE joint connections of a conventional SPSW with a rocking connection combined with Post-Tension elements. y Energy dissipation provided by yielding

of infill plate only (not shown in figure) y HBE, VBE and P.T. components

designed to remain essentially elastic y Elastic elongation of P.T. about a rocking

point provides a self-centering mechanism

UB Test-Setup (Full Infill Plate Frames)

UB Specimen (Rocking about Flanges)

13

8/12/2012

Accommodating Beam Growth with Large Columns

Courtesy of Greg MacRae, University of Canterbury, New Zealand

NewZ-BREAKSS Rocking Connection Rocking Point (Ea. End of HBE) W6x VBE

Radius Cut-Out Flange Reinf. Plate

UB Test Frame: Additional Test Frame Configurations:

Test Frames w/ Infill Strips

New Zealand-inspired – Buffalo Resilient Earthquake-resistant Auto-centering while Keeping Slab Sound (NewZ-BREAKSS) Rocking Connection

Frame w/ NewZBREAKSS Conn.

NewZ-BREAKSS Rocking Connection

Light Gage Web Plate W8x HBE

Continuity Plate VBE Web Dblr Plate Post-Tension (Ea. Side of HBE Web)

P tT i Post-Tension Eccentricity

Stiffener Plates (Typ.) Cant HBE Web (Ea. End of HBE)

Shear Plate w/ Horiz. Long Slotted Holes

Comments: ¾Schematic detail shown of UB 1/3 test frame connection currently being tested at UB ¾Eliminates PT Frame expansion by HBE rocking at the beam top flanges only

NewZ-BREAKSS Rocking Connection

NewZ-BREAKSS Rocking Connection

14

8/12/2012

UB NewZ-BREAKSS Test Frame

UB NewZ-BREAKSS Test Frame

UB NewZ-BREAKSS Test Results NewZ-BREAKSS Hysteresis Full Infill Plates -3.4 60

-2.7

50 40

Base Shear (kips)

-2.0

0.167Δy 0.33Δy 0.67 Δy 1.0Δy 2Δy 3Δ 3Δy

30 20

-1.4

Top Story Drift (%) -0.7 0.0 0.7 1.4

2.0

2.7

3.4

4Δy 2% drift 2.5% drift 3% drift

Comments: ¾Displacement control at top level actuator with a slaved Force control at level 1 & 2 2.

10

¾Force control load pattern of 1, 0.658, 0.316 at level 3, 2, 1 actuators used based on approximate first mode shape.

0 -10 -20 -30 -40 -50 -60 -5

-4

-3

-2 -1 0 1 2 Top Story Displacement (in)

3

4

5

Discrete Strips Alternative

NewZ-BREAKSS Hysteresis Full Infill Plates - SAP2000 Top Story Drift (%) -4.5

-3

-1.5

0

1.5

3

4.5

80

Base Shear (k (kips)

60 40 20

1) 2) 3) 4)

Test Frame - 2x0.5" strds APT = 4x0.5" strds APT = 6x0.5" strds APT = 6x0.6" strds

0 -20

*Residual Drift 1) 1.85% 2) 1.0% 3) 0.85% 4) 0.58% *modify HBE/VBE sizes as required

-40 -60 -80 -8

-6

-4

-2

0

2

4

6

8

Top Story Displacement (in)

15

8/12/2012

UB Test Results – NewZ-BREAKSS Top Story Drift (%) -6 -4.5 -3 -1.5

0

1.5

3

4.5

6

ƒNo separation of the infill strips occurred (also observed with the flange rocking case). ƒTesting stopped to be able to reused VBEs for subsequent shake table testing.

60

Base Shear (kips)

SAP2000: 10% Comp.

40 20 0 -20 PT Yielding Occured At Approx. 4.5% Top Story Drift

-40 -60 -10.5 -7.5

-4.5

-1.5

1.5

4.5

7.5

10.5

Top Story Displacement (in)

Eccentrically Braced Frame Tubular-link Eccentrically TubularBraced Frames (TEBF) a.k.a. EBF with BuiltBuilt-up Box Links

Proof--of Proof of--Concept Testing

Tubular--link EBF Tubular „

„

„

„

EBFs with wide-flange (WF) links require lateral bracing of the link to prevent lateral torsional buckling Lateral bracing is difficult to provide in b bridge piers Development of a laterally Fyf tw stable EBF link is warranted Fyw Consider rectangular crosstf section – No LTB

d

16

8/12/2012

Finite Element Modeling of Proof--of Proof of--Concept Testing

Link Testing – Results Large Deformation Cycles of Specimen X1L1.6

Hysteretic Results for Refined ABAQUS Model and Proof-of-Concept Experiment

Design Space Stiffened Links Unstiffened Links 0.64

1.67

E Fyw

Implementation of TEBF

b tf 0.64

ρ = 1.6

E Fyw d tw

„

E Fyf

ρ

Some slenderness limits accidentally missing from AISC 341-10

Towers of temporary structure to support and provide seismic resistance i t to t deck d k off self-anchored suspension segment of East Span of SanFrancisco-Oakland Bay Bridge during its construction

Earthquakes

Multi--Hazard Design Concept Multi Why Multi-Hazard Engineering Makes Sense?

17

8/12/2012

Storm Surge or Tsunami

Collision

http://www.dot.state.mn.us/bridge/Manuals/LRFD/June2007Workshop/10%20Pier%20Protection.pdf

Fire

Blast

Suicide truck-bomb collapsed the Al-Sarafiya bridge and sent cars toppling into the Tigris River (AP, (Baghdad, Iraq, April 2007)

Multi--hazard solution Multi „

„

„

„

A true multi-hazard engineering solution is a concept that simultaneously has the desirable characteristics to protect and satisfy the multiple (contradicting) constraints inherent to multiple hazards Needs holistic engineering design that address all hazards in integrated framework A single cost single concept solution (not a combination of multiple protection schemes) Pay-off: Reach/protect more cities/citizens

Concrete--Filled Steel Tubes Concrete (CFST) for blast and seismic performance

18

8/12/2012

CFST Piles „

“The Loma Prieta and Northridge earthquakes in California and the Kobe, Japan quake, along with reexamination of largediameter cylinder-pile cylinder pile behavior in the Alaskan earthquake of 1964, have demonstrated the superior ductility of concrete-filled steel tubular piles.” (Ben C. Gerwick Jr., ASCE Civil Engineering Magazine, May 1995)

„ „

CFST Column Specimen (1st Series)

CFST Column Test Results Test 5: Bent 1, C5 (1.3X, W, Z=0.75m)

16.5”

164” CAP-BEAM C5

C4

68.5”

69.5”

6” 6

5” 5

59”

C6

Bridge carrying Broadway Ave. over the railroad in City of Rensselaer, NY Built 1975. No major rehab, although joints and wearing surface were redone

4” 4

Dmax = 76 mm

32”

FOUNDATION BEAM

Gap = 3 mm

164” Concrete-Filled Steel Tube

Concrete (no rebars)

Damage Progress of CFST Column (Column Deformations) 1.2 deg (0.021 rad)

2.2 deg (0.038 rad)

4.9 deg (0.085 rad)

18.7 deg (0.327 rad)

Fracture of Column

Seismically Designed Ductile Column „ „

10.5 deg (0.182 rad)

5.0 deg (0.088 rad)

21.9 deg (0.382 rad)

Buckling of Steel Tube

Explosion 3.8 deg (0.067 rad)

8.3 deg (0.144 rad)

17.0 deg (0.297 rad)

Fracture of Steel Tube

Covered Concrete

Plastic Deformation (Test 6 : B2-C4)

„ Blew Away

Plastic Deformation (Test 9 : B2-C6)

On-set of Column Fracture (Test 10 : B2-C5)

Post-fracture of Column (Test7 : B2-C4)

Shear Failure Seismic Design Alone is not a Guarantee of MultiHazard Performance Need Optimal Seismic/Blast Design

19

8/12/2012

Comparison of Blast Parameters

Jacketed NonNonDuctile Column (Seismic Retrofit) „ „

CFST Tests

0.10W Test 5 Test 4

250

750

Test 3 Test 9,10 Test 7

Test 6

Comparison of Column Damage Horizontal Deformation (mm)

Test 1,3 Test 2,4

1

1

1

38

3

59

5

80

7

6

6

10

10

17

15

102 123 144 165

8

19

19

11

21

23

12

24

27

12

28

31

188

13

32

35

216

14

37

39

242

15

40

44

263

16

45

49

285

16

50

52

309

15

52

56

328

16

57

61

347

15

62

65

367

14

67

71

379

All longitudinal bars fractured.

Test 6 CFST C4 (x = 1.6 X)

Test 1 RC1 (x = 2.16 X)

0.7 deg (0.012 rad)

All longitudinal 71 bars fractured. 75

13

74

Standoff Distance (in X)

3 3.25

Calibration Work Fracture of Column

Explosion

Blew Away

250

3.8 deg (0.067 rad)

18

Test 2

Test 1

0.8 1.3 2 0.6 1.1 1.6 2.16

24 (Max)

W

0.55W

Reaction Frame

Again Shear Failure Same conclusions

1.2 deg (0.021 rad)

RC, SJ Tests

W

79

2.9 deg (0.051 rad)

Test 2 RC2 (x = 3.25 X)

Test 3 SJ2 (x = 2.16 X)

Test 4 SJ1 (x = 3.25 X)

Blast Simulation Results

e )

Post-fracture of Column (Test7 : B2-C4)

Proposed Multi Hazard Concept • Analysis of concrete filled double skin tubes (CFDST) showed they can offer similar performance as CFST • CFDST concentrates materials where needed for higher strength-to-weight ratio

20

8/12/2012

Blast Test Results

S1 @ 3% Drift

S1 @ 7.5% Drift

S1 @ 10% Drift

S5 @ 3% Drift

S5 @ 6% Drift

S5 @ 7.5% Drift

Enhanced Steel Jacketed Column

21

8/12/2012

ERDC Test on ESJC • Results

Structural Fuses (SF)

Analogy „

structural fuse, d

mass, m

Sacrificial element to protect the rest of the system. frame f frame, braces, b

Ground Motion, üg(t)

Model with Nippon Steel BRBs

Benefits of Structural Fuse Concept: „

Seismically induced damage is concentrated on the fuses V V Following a damaging earthquake only the fuses V would need to be replaced VV Once the structural fuses are removed, the elastic structure returns to its original position (self-recentering capability)

Total

Eccentric Gusset Gusset--Plate

p

„

αK1 = Kf

y

Structural Fuses

K1

yd yf

„

Ka

Δya

Frame

Kf

Δyf

u

22

8/12/2012

Test 1 First Story BRB

Test 1

(PGA = 1g)

40

1st Story Axiaal Force (kips)

30 20 10 0 -0.5

-0.4

-0.3

-0.2

-0.1

-10

0

0.1

0.2

0.3

0.4

0.5

-20 -30 -40 Axial Deformation (in)

Test 1 (Nippon Steel BRB Frame) First Story Columns Shear 1st Story Column ns Shear (kN)

100

-5

75 50 25 0 -4

-3

-2

-1

-25

0

1

2

3

4

5

-50 -75 -100 Inter-Story Drift (mm)

ABC Bridge Pier with Structural Fuses Specimen S2S2-1

New “Short Length” BRB Developed by Star Seismic

23

8/12/2012

Specimen with BRB Fuses

Specimen with BRB Fuses

Controlled Rocking/Energy Dissipation System „

Rocking Frames (RF) „

Absence of base of leg connection creates a rocking bridge pier system partially isolating the structure Installation of steel yielding devices (buckling-restrained braces) at the steel/concrete interface controls the rocking response while providing energy dissipation Retrofitted Tower

Existing Rocking Bridges South Rangitikei Rail Bridge

Lions Gate Bridge North Approach

Static, Hysteretic Behavior of Controlled Rocking Pier

FPED=0 FPED=w/2

Device Response

24

8/12/2012

Design Procedure Design Chart:

Design Constraints z

h/d=4 10

Acceleration ⇒

Limit forces through vulnerable members using structural “fuses”

8

6

z

Velocityy Control impact energy to foundation and impulsive loading on tower legs by limiting velocity ⇒

Displacement Ductility Limit μL of specially detailed,

4

2



ductile “fuses” z

Auub

z

Aub ((in2)

„

0

0

β