Seismic Design and Behavior Outline of Presentation of ... · PDF fileSeismic Design and...

June 4, 2003

1

Seismic Design and BehaviorSeismic Design and Behaviorof Composite (RCS) Framesof Composite (RCS) Frames

Gregory G. DeierleinStanford University

with contributions by Paul Cordova (SGH), Sameh Mehanny(Univ. of Cairo), Sherif El-Tawil (Univ. of Michigan), Ryoichi

Kanno (Nippon Steel), & others

Gregory G. Gregory G. DeierleinDeierleinStanford UniversityStanford University

with contributions by Paul Cordova (SGH), with contributions by Paul Cordova (SGH), SamehSameh MehannyMehanny(Univ. of Cairo), (Univ. of Cairo), SherifSherif ElEl--TawilTawil (Univ. of Michigan), Ryoichi (Univ. of Michigan), Ryoichi

KannoKanno (Nippon Steel), & others(Nippon Steel), & others

Acknowledgments:National Science Foundation (USA), National Science Council (TW)

Pacific Earthquake Engineering Research (PEER) CenterNational Center for Research in Earthquake Engineering (TW)

Earthquake Engineering Research InstituteNippon Steel Corporation, American Institute of Steel Construction

Acknowledgments:National Science Foundation (USA), National Science Council (TW)

Pacific Earthquake Engineering Research (PEER) CenterNational Center for Research in Earthquake Engineering (TW)

Earthquake Engineering Research InstituteNippon Steel Corporation, American Institute of Steel Construction

Outline of Presentation

• Background & Applications

• Composite RCS Beam-Column Joints

• Large Scale Composite RCS Frame Test– Design/Construction/Testing– Analysis and Interpretation

• The New Frontier

Early “Mixed” System

Texas Commerce Plaza• 75-story, RC perimeter frame

• 1982, Houston, TX

• CBM Engineers, Houston

Three Houston Center• 52-story RCS perimeter frame

• 1983, Houston TX

• Walter P. Moore Associates

Norwest Center Building• Composite “Mega-Frame”

• Minneapolis, MN, 1987

• CBM Engrs., Houston, TX

June 4, 2003

2

Composite Column

Beam-Column Joint

Face Bearing Plate

Vertical Joint Reinforcement

Mellon Bank Tower• 55 Story (1991)• Composite Moment

Perimeter Frame & Composite Core

• WSP Cantor Steinuk

U.S. Design/Construction Practice

• Composite construction evolved as a variation of steel construction with most applications for mid-to high-rise building structures.

• Advantages of Composite– Economy of concrete in vertical members – Speed of construction– Versatility in design and construction

• Disadvantages of Composite– Mixing of construction trades– Lack of design standards, guidelines, etc.

Japanese RCS Systems

• Low-rise construction (3-5 stories)– Shopping centers and offices– About 100 RCS buildings in Japan

• Construction Methods– Precast columns– Cast-in-place with rebar erection columns

• High-Seismic Regions

CastCast--inin--Place RCS ConstructionPlace RCS Construction

steel beam

steel erectioncolumn

reinforcingbar cage

formwork

RC column

Steel Erection FrameCast-in-Place

Reinforcing Bar CageReplaces Steel

Erection Column(Japanese Construction Co.)

PrePre--Cast RCS ConstructionCast RCS Construction

Precast Beam-ColumnModules

RC Column

Steel BandPlate

Steel BeamReinforce Bars

Grouted Splices

> 2(beam depth)

Bolted BeamSplices

Shimizu Corporation, Japan

June 4, 2003

3

Advantages for Seismic DesignAdvantages for Seismic Design““postpost--NorthridgeNorthridge””

steel beam continuous through joint

avoids welding at location of maximum forces

stable hysteretic behavior““ThroughThrough--BeamBeam”” DetailDetail

Steel Beam

Reinforced Concrete Column

Steel Band Plate

Face BearingPlate

Longitudinal Reinforcement

Tie Reinforcement

Stiffener

US Seismic Design Standards

• ASCE/SEI 7 (2005) & IBC (2006)– based on 1994 & 1997 NEHRP– general criteria for systems, members and connections

• AISC Seismic Provisions - Part II Composite (2005)– based on 1994 NEHRP chapter on composite structures– criteria for composite systems, members, connections

• AISC (2005) and ACI-318 (2005)– steel and RC members and connections– composite beams and columns (limited)

• ASCE RCS Connection Design Guidelines (1994, 2007)

20 Story Design Example

6 @ 20ft

5 @ 20ft

Structural Layout

Specifications– 20-story “SAC” frame– Perimeter frame system– IBC 2006

Ss = 1.5gS1 = 0.72g

– R = 8, Cd = 5.5

Mid-Rise:Competitive with Steel Frame

Controlling Design Criteria– Strength– SCWB– Drift

Steel vs. RCS DesignRCS Frame Design

• Beams: W24 – W30– Steel quantity: 3.0psf

• Columns– 30” x 35”, 30” x 30”– Concrete quantity:

0.16ft3/ft2; rebar 1.4psf

• Gravity Framing– Steel quantity: 7.6psf

Steel Frame Design

• Beams: W24 – W30– Steel quantity: 3.0psf

• Columns– W24x335,W24x279– Steel quantity: 4.8psf

• Gravity Framing– Steel quantity: 7.6psf

Beam-Column Joint Design

• Joint size is dictated by member designs• Strength based on ASCE guidelines• Simple joint detail develops Mp,beams

Steel bandSteel Band Plate

Face Bearing Plate

Steel BeamRC Column





• The Future Frontier

June 4, 2003

4

Steel Beam

Reinforced Concrete Column

Steel Band Plate

Face BearingPlate

Longitudinal Reinforcement

Tie Reinforcement

Stiffener

RCS BeamRCS Beam--Column Connection Column Connection Tests & Design GuidelinesTests & Design Guidelines

Research 1985 - 2004*:

• Transfer Mechanisms

• Details (band plates, etc.)

• Cyclic Behavior

• Exterior & 2-way joints

• Concrete Slab

• High Strength Concrete

• Fiber Concrete …““throughthrough--beambeam”” detaildetail

* total database of 400+ tests (world wide)

Connection Tests & Design Models• US Research & Guidelines

Deierlein & Sheikh, UT Austin, 1989Kanno & Deierlein, Cornell Univ., 1994Parra-Montesinos and Wight, Univ. of Michigan, 2000Bracci et al., Texas A&M, 2000

• Japanese Research & GuidelinesAIJ-SRC method (1987)Modified AIJ-SRC (Izaki et al., Sakaguchi, etc.; 1988-97)Kim and Noguchi (1998) Nishimura-Minami model (1989)

• ASCE Guidelines (1994, 2007 update)

Deierlein et al., UT Austin, 1989

Composite Beam-Column Joint Tests

TypicalTypicalJoint DetailJoint Detail

TJD = 0.01 TJD = 0.01 radrad(after 2 cycles)(after 2 cycles)

TJD > 0.05 TJD > 0.05 radradExposed CoreExposed Core

(Deierlein, 1989; Kanno, 1993)

COLUMN

BEAM

PLASTIC HINGE

Modes of Subassembly FailureModes of Subassembly Failure

BeamBeamJointJoint MixedMixed Beam-HingingJoint Panel Shear

Modes of Subassembly FailureModes of Subassembly Failure

June 4, 2003

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Modes of Subassembly Failure

Beam Hinging Joint Shear

-100 -50 0 50 100

Displacement (mm)

-200

-100

0

100

200

Bea

m S

hear

(kN

)

µ = 1 2 3 4

-100 -50 0 50 100Displacement (mm)

-200

-100

0

100

200

Bea

m S

hear

(kN

)

µ = 1 2 3 4Connection Behavior & Design Model

Outer Panel Inner Panel Outer Panel

Inner Panel Failure Modes

Bearing failure Panel shear failure

Vtv

Concrete crushing

Gap

Concrete crushing

Kinking Panel shear yielding

Vth

Mbi

Vbi

Inner Panel Failure Modes

Panel shear failure Bearing failure

Typical Through-Beam DetailsE-FBP

FBP / W-FBP

Face bearing plate (FBP) E-FBP

Small column

Small columnVJR

Vertical joint reinf. (VJR)

Steel band

Transverse beam

Steel band Transverse beam

Basic Equations for Model (Kanno)

• Each element strength is calculated by the smaller of two modes:

• Strengths are added:

• Important aspect:– Simultaneous failure of

inner and outer elements for entire joint failure

V b = V bi + V bo

V bi = min Vbe , V swc{ }

V bo = min Vbo , V scf{ }

Vbe

VscfVbo

Vswc

Outer element

Bearing Panel shear

ShearBond

Inner element

June 4, 2003

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Vertical Bearing failure

Panel shear failure

Gap

Concrete crushing

Kinking Panel shear yielding

Vtv

Concrete crushing

Gap

Concre crus

KVth

Mbi

Vbi

Joint Failure Models

• 1994 ASCE Joint design model– Deierlein & Sheikh, UT Austin, 1989

• Follow-on studies– Kanno et al. 1994

– Parra-Montesinos et al. 2000, 2003

– Bracci et al. 2000

• 2007 Updated Guidelines

– Synthesized past work

– NCREE testing program results

– Updated models and incorporated new details 0

0.2

0.4

0.6

0.8

1

1.2

1.4

Vbc

/Vbe

KA

NN

O O

JB1-

0

KA

NN

O O

JB4-

0

KA

NN

O O

JB5-

0

KA

NN

O O

JB6-

1

SH

EIK

H 2

SH

EIK

H 6

Joint Bearing Failure

Mean = 0.94COV = 0.076

ASCEUpdated

Vertical bearing failurePr

edic

ted/

Mea

sure

d St

reng

th

0

0.2

0.4

0.6

0.8

1

1.2

1.4

Vbc

/Vbe

KA

NN

O O

JS1-

1K

ANN

O 0

JS2-

0K

AN

NO

OJS

3-0

KA

NN

O O

JS4-

1K

AN

NO

OJS

5-0

KA

NN

O O

JS6-

0K

ANN

O 0

JS7-

0K

ANN

O H

JS1-

0K

ANN

O H

JS2-

0D

EIER

LEIN

10

DEI

ERLE

IN 1

1D

EIER

LEIN

13

DEI

ERLE

IN 1

5D

EIER

LEIN

17

SH

EIK

H 4

SH

EIK

H 5

SH

EIK

H 7

SH

EIK

H 8

PAR

RA

1P

ARR

A 6

PAR

RA

9

Joint Panel Shear Failure

Mean = 0.97COV = 0.135

ASCEUpdated

Panel shear failure

Pred

icte

d/M

easu

red

Stre

ngth





• The Future Frontier

FullFull--Scale 3Scale 3--Story, 3Story, 3--Bay Bay Composite Moment FrameComposite Moment FrameNCREE, Taipei, TaiwanNCREE, Taipei, Taiwan

Rationale for Full-Scale Test

1. PROOF OF CONCEPT for innovative systems: construction, design, and performance

2. BEHAVIORAL EFFECTS: complete system study, precast & bolted splices, composite beam/slab, load introduction, etc.

3. CALIBRATION & VALIDATION of analysis models

4. DATA for performance-based earthquake engineering: (large deformations, immediate occupancy through near-collapse)

5. CAPSTONE project for past 20 years of research

6. DEMONSTRATE RELIABILITY for high seismic zones

Full Scale 3Full Scale 3--Story TestStory TestCollaborators: Dr. K.C. Tsai, C.H. Chen, W.C. LaiCollaborators: Dr. K.C. Tsai, C.H. Chen, W.C. Lai

Designed per IBC Designed per IBC 20032003

NCREE lab in NCREE lab in Taipei, TaiwanTaipei, Taiwan

4 Pseudo4 Pseudo--dynamic dynamic EQEQ’’s and final s and final static pushoverstatic pushover

Complementary Complementary subassembly testssubassembly tests

Columns Columns -- 650x650650x650mm, mm, ρρgg = 0.03= 0.03Beams Beams –– 11--600x200600x200mmmm, 2, 2--500x200500x200mmmm, 3, 3--400x200400x200mmmm

1.2m

1m

Seismic Design CriteriaSeismic Design Criteria

IBC 2003IBC 2003Design Hazard (SDesign Hazard (SDSDS = 1 g; 10% in 50 year)= 1 g; 10% in 50 year)R = 8 (Composite Special Moment Frame)R = 8 (Composite Special Moment Frame)

Drift: Drift: ∆∆dd**CCdd < 0.02h< 0.02hPeriod: 1.2TPeriod: 1.2Taa = 0.6 sec= 0.6 secAccidental torsion (7.5% increase in V/W)Accidental torsion (7.5% increase in V/W)

Design Base ShearDesign Base ShearV/W = (SV/W = (SDSDS/R)*1.075 = 0.134/R)*1.075 = 0.134V = 261 kips = 1161kNV = 261 kips = 1161kN

June 4, 2003

7

Governing CriteriaGoverning Criteria

BeamsBeams

Sized for strength (1.42D+0.5L+E) Sized for strength (1.42D+0.5L+E)

ColumnsColumns

Controlled by SCWB Controlled by SCWB

Composite JointsComposite Joints

Standard details (fulfills SJWB criterion)Standard details (fulfills SJWB criterion)

Drift Criteria is automatically satisfiedDrift Criteria is automatically satisfied

Precast Plant

1 2

34

1st Floor Beam-Column Modules

Piece TogetherBeam-Column

Modules Temporary Bracing

1st Floor Steel Beams

Lift steel beaminto place

Fasten the beam splice connection

1st Floor Steel Beams 1st Floor Loading Beam

LoadingBeam

June 4, 2003

8

Grouting 1st Floor Splice2nd & 3rd Floors

+ 2 Days

FullFull--Scale 3Scale 3--Story, 3Story, 3--Bay Bay Composite Moment FrameComposite Moment FrameNCREE, Taipei, TaiwanNCREE, Taipei, Taiwan

3 Actuators per floor3 Actuators per floor1000kN, 1000kN, ±±500mm stroke500mm stroke PseudoPseudo--Dynamic Testing MethodDynamic Testing Method

M a + C v + K d = fR

These can all be modeled analytically in the computer

Compute by step-by-stepintegration procedure(Newmark Explicit)

Impose di+1 &recover forces

Test Frame

=d3

d2

d1m1

m2

m3

36 DOF

Static Condensation - 3DOFGround Acc.

Input Ground MotionsInput Ground Motions

EQ#1 EQ#1 –– 50%in50yr50%in50yr ChiChi--Chi RecordChi Record

EQ#2 EQ#2 –– 10%in50yr10%in50yr Loma Prieta RecordLoma Prieta Record

EQ#3 EQ#3 –– 2%in50yr2%in50yr ChiChi--Chi RecordChi Record

EQ#4 EQ#4 –– 10%in50yr 10%in50yr Loma Prieta RecordLoma Prieta Record

Final Static Pushover Final Static Pushover (RDR ~ 8%)(RDR ~ 8%) (IBC 2003)(IBC 2003)

0 5 10 15 20 25 30 35 40-0.3

-0.2

-0.1

0

0.1

0.2

0.3

Acc

eler

atio

n (g

)

Time (sec)

1989 Loma Prieta Earthquake

Acc

eler

atio

n (g

)

Time (s)

0 5 10 15 20 25 30 35 40 45-0.3

-0.2

-0.1

0

0.1

0.2

0.3

Time (sec)

Acc

eler

atio

n (g

) 1999 Chi–Chi Earthquake

Acc

eler

atio

n (g

)

Time (s)

0 0.5 1 1.5 2 2.5 30

0.2

0.4

0.6

0.8

1

1.2

Sa (g

)

Period (sec)

Chi Chi Eq.Loma Prieta Eq.

Response SpectrumUnscaled Records

Tn=1secSa (g

)

Period (s)

Scaled to 0.4g (1.27x)Scaled to 0.4g (1.27x)



Overview of Measured ResponseOverview of Measured Response

0 20 40 60 80 100 120 140 160-500

-400

-300

-200

-100

0

100

200

300

400

Time (sec)

Roo

f Dis

plac

emen

t (m

m)

EQ1: 50/50 TCU082

EQ2: 10/50 LP89G04 EQ3: 2/50 TCU082

EQ4: 10/50 LP89G04

2a 2b

-0.06 -0.04 -0.02 0 0.02 0.040

0.5

1

1.5

2

2.5

3

IDR

Floo

r

EQ 1: 50/50EQ 2a: 10/50EQ 2b: 10/50EQ 3: 2/50EQ 4: 10/50

-4000 -3000 -2000 -1000 0 1000 2000 3000 40000

0.5

1

1.5

2

2.5

3

Story Force (kN)

Floo

r

50/50 Event 10/50 Event 2/50 Event 10/50 Event

2.0%

3000kN3800kN3.0%5.3% 3800kN

3.0%

2200kN

Interstory Drift Ratio Story Force (kN)

Floo

r

Floo

r

Roo

f Dis

plac

emen

t (m

m)

Time(sec)

June 4, 2003

9

Frame DamageFrame DamageAfter Design Level EventAfter Design Level Event

0 20 40 60 80 100 120 140 160-500

-400

-300

-200

-100

0

100

200

300

400

Time (sec)

Roo

f Dis

plac

emen

t (m

m)

EQ1: 50/50 TCU082

EQ2: 10/50 LP89G04 EQ3: 2/50 TCU082

EQ4: 10/50 LP89G04

2a 2b

-0.06 -0.04 -0.02 0 0.02 0.040

0.5

1

1.5

2

2.5

3

IDR

Floo

r

EQ 1: 50/50EQ 2a: 10/50EQ 2b: 10/50EQ 3: 2/50EQ 4: 10/50

-4000 -3000 -2000 -1000 0 1000 2000 3000 40000

0.5

1

1.5

2

2.5

3

Story Force (kN)

Floo

r

10/50 Event

3800kN3.0%

Story Force (kN)

Floo

r

Floo

r

Roo

f Dis

plac

emen

t (m

m)

Time(sec)

Interstory Drift Ratio

EQ#2: 10%in50yr Loma PrietaEQ#2: 10%in50yr Loma PrietaTypical Damage in First FloorTypical Damage in First Floor

θp ≈ 1.2%

θp ≈ 2.1%

Frame DamageFrame DamageAfter Maximum Credible EventAfter Maximum Credible Event

0 20 40 60 80 100 120 140 160-500

-400

-300

-200

-100

0

100

200

300

400

Time (sec)

Roo

f Dis

plac

emen

t (m

m)

EQ1: 50/50 TCU082

EQ2: 10/50 LP89G04 EQ3: 2/50 TCU082

EQ4: 10/50 LP89G04

2a 2b

-0.06 -0.04 -0.02 0 0.02 0.040

0.5

1

1.5

2

2.5

3

IDR

Floo

r

EQ 1: 50/50EQ 2a: 10/50EQ 2b: 10/50EQ 3: 2/50EQ 4: 10/50

-4000 -3000 -2000 -1000 0 1000 2000 3000 40000

0.5

1

1.5

2

2.5

3

Story Force (kN)

Floo

r

5.3% 3800kN

Story Force (kN)

Floo

r

Floo

r

Roo

f Dis

plac

emen

t (m

m)

Time(sec)

Interstory Drift Ratio

2/50 Event

EQ#3: 2%in50yr ChiEQ#3: 2%in50yr Chi--ChiChiTypical Damage in First FloorTypical Damage in First Floor

θp ≈ 5.5%

θp ≈ 6.0%

up to 75mm

b / t < 52 / √Fy

Final PushoverFinal Pushover

RC Column Base

10% Drift

8% Drift

3% Drift

Max Drift Final PushoverFinal Pushover

0 2 4 6 80

500

1000

1500

2000

2500

3000

3500

Relative Roof Drift

Base

She

ar (k

N)

Maximum Drift 1st Floor = 10.1%2nd Floor = 8.0%3rd Floor = 3.0%

Maximum Strength

Design

x2.8

Roof Drift

Bas

e Sh

ear (

kN)

Beam–Column Joint

June 4, 2003

10

Final PushoverFinal Pushover

1.63 1.54 1.54 1.63

1.28 1.76 1.76 1.28

1.31 1.42 1.42 1.31

ACI/AISC SCWB RatiosPer Joint: ΣMc/ΣMb > 1.2

Steel Strength

2-Story Mechanism

1.09 1.24 1.24 1.63

0.86 1.42 1.42 1.28

0.84 1.03 1.03 1.46

ACI/AISC SCWB RatiosPer Joint: ΣMc/ΣMb > 1.2

Composite Strength

1.3

1.2

Local BucklingLocal Buckling

FullFull--ScaleScaleContinuity provided Continuity provided restraint against severe restraint against severe bucklingbucklingLarge buckles Large buckles straightened out on straightened out on opposite cycles (esp. opposite cycles (esp. along side interior along side interior joints)joints)

SubassemblySubassemblyBoundary conditions Boundary conditions allow beam shortening allow beam shortening Buckles build up over Buckles build up over each of the cycles. each of the cycles. Overestimates amount of Overestimates amount of damagedamage

Actuator Force

Local BucklingLocal Buckling

FullFull--ScaleScale SubassemblySubassembly

Actuator Force

Slab PerformanceSlab Performance

FullFull--ScaleScaleExceeded expectations Exceeded expectations and remained intactand remained intactNo shear stud fracturesNo shear stud fracturesRealistic load transfer Realistic load transfer alleviates stresses on alleviates stresses on slabslab

SubassemblySubassemblyTypically fails by local Typically fails by local slab crushing and slab crushing and shear stud fractures.shear stud fractures.Slab failure initiates Slab failure initiates more buckling in top more buckling in top flangeflange

Actuator Force

+ Mb + Mb + Mb

- Mb- Mb- Mb

+ Mb

- Mb

Rotational Springsin Series

Joint Model

Analytical ModelingAnalytical ModelingOpenSees OpenSees (http://(http://opensees.berkeley.eduopensees.berkeley.edu))

Fiber Sections

Beam-Column

creteushing

Kinking Panel s yieldi

Panel Shear

Vtv

oncretecrushing

Gap

Con cru

Vth

Mbi

Vbi

Vertical Bearing

Tsai 2002

Analytical ModelingAnalytical ModelingFiber Element CalibrationFiber Element Calibration

concrete slabIPE 330

P,∆

L = 157.5in

HE 360BL = 55.12in

Bursi & Ballerini 1996 -5 -4 -3 -2 -1 0 1 2 3 4 5-80

-60

-40

-20

0

20

40

60

80

100

Displacement (in)

Hor

izon

tal L

oad

(kip

s)

TestOpenSees

Bursi & Ballerini 1996

Drift (in)

Forc

e, P

(kip

s)

-300 -200 -100 0 100 200 300-3

-2

-1

0

1

2

3x 106

Mom

ent(k

N-m

m)

Drift (mm)

OpenSeesTest

Tsai 2002

Drift (mm)

Mom

ent (

kN-m

m)

Stre

ssSt

ress

StrainStrain

StrainStrain

Stre

ssSt

ress

CoreCore

CoverCover

SteelSteel

StrainStrain

Stre

ssSt

ress

SlabSlab

Effective slab width:Effective slab width:bbeffeff = = bbcolcol

June 4, 2003

11

-0.15 -0.1 -0.05 0 0.05 0.1 0.15

-400

-300

-200

-100

0

100

200

300

400B

eam

She

ar (k

N)

Rotation (rad)

Total Joint RotationOJB1-0Mps = 10106 kN-mmMvb = 7327 kN-mm

TestOpenSees

Analytical ModelingAnalytical ModelingComposite Joint CalibrationComposite Joint Calibration

Joint Bearing

Ref: El-Tawil, Deierlein, Kanno

Vtv

reteshing

G

C

Vth

Mbi

Vbi GapConcreteCrushing

Bearing Failure

teing

nking Pan yie

ConcreteCrushing

Panel ShearYielding

Kinking

Panel Shear Failure -0.15 -0.1 -0.05 0 0.05 0.1 0.15

-400

-300

-200

-100

0

100

200

300

400

Bea

m S

hear

(kN

)

Rotation (rad)

Total Joint RotationOJS3-0M

ps = 6789 kN-mm

Mvb

= 9453 kN-mm

TestOpenSees

Joint Shear

0 5 10 15 20 25 30 35 40 45-200

-150

-100

-50

0

50

100

150

200

Time (sec)

Roo

f Dis

p. (m

m)

TCU082 50/50TestOpenSees

Analytical ModelingAnalytical Modeling50%in50 year Event50%in50 year Event

EQ#1 – 50/50 TCU082

Good Agreement Phase Shift

Time (s)

Roo

f Dis

plac

emen

t (m

m)

-6 -4 -2 0 2 4 60

1

2

3

IDR

Floo

rFl

oor

IDRmax-4 -3 -2 -1 0 1 2 3 4

0

1

2

3

S tory Shear (1000kN)

Floo

rFl

oor

Story Shear (1000kN)

Maximum ResponseMaximum ResponseDispDisp. Error < 20%. Error < 20%Shear Error < 10%Shear Error < 10%

Difference in period Difference in period shift noticeable near shift noticeable near latter half of event.latter half of event.

T = 1.0s T = 1.3s

-6 -4 -2 0 2 4 60

1

2

3

IDR

Floo

r

0 5 10 15 20 25 30-600

-500

-400

-300

-200

-100

0

100

200

300

400

Time (sec)

Roo

f Dis

p. (m

m)

TCU082 2/50

TestOpenS eesGood Agreement

Large local bucklesin beam flangesR

oof D

ispl

acem

ent (

mm

)

Time (s)

PeakResponse

-4 -3 -2 -1 0 1 2 3 40

1

2

3

S tory Shear (1000kN)

Floo

r

Floo

r

IDRmax

Floo

r

Story Shear (1000kN)

65%

Maximum ResponseMaximum ResponseDispDisp. Error < 65%. Error < 65%Shear Error < 20%Shear Error < 20%

Large differences in Large differences in latter half of event.latter half of event.

Local buckles not modeled

Analytical ModelingAnalytical Modeling2%in50 year Event2%in50 year Event

T = 1.5s T = 1.7s

0 0.5 1 1.5 2 2.50

0.5

1

1.5

2

2.5

Sa (g

)

Period (sec)0 0.5 1 1.5 2 2.5

0

0.5

1

1.5

2

2.5

Sa (g

)

Period (sec)

0 10 20 30 40 500

0.5

1

1.5

2

2.5

Sd (cm)

Sa (g

)

T=1.5s0 10 20 30 40 50

0

0.5

1

1.5

2

2.5

Sd (cm)

Sa (g

)Period ElongationPeriod Elongation

Spe

ctra

l Acc

eler

atio

n (c

m)

Loma Prieta, Scaled to 10/50

T=1.0s T=1.3s

114% in Sd

26% in Sa

Period (s)

Loma Prieta, Scaled to 10/50

IBC2003 2%in50

IBC2003 10%in50

Spectral Displacement (cm)

All records scaled to the spectral All records scaled to the spectral hazard (Shazard (Saa) at the first natural ) at the first natural period of frame (Tperiod of frame (T11=1.0s).=1.0s).

The first event (50%in50yr) cause The first event (50%in50yr) cause period elongation to 1.3 seconds.period elongation to 1.3 seconds.

The following design level event The following design level event (10%in50yr) actually represented a (10%in50yr) actually represented a higher hazard level (~2%in50)higher hazard level (~2%in50)

Emphasizes importance of Emphasizes importance of appropriate EQ intensity measures appropriate EQ intensity measures that captures spectral shapethat captures spectral shape

Shift during 10%in50

Spe

ctra

l Acc

eler

atio

n (c

m)

Relating Analysis to Physical DamageRelating Analysis to Physical Damage

0.0 ≤ Dθ ≤ 1.0

Significant, questionable repair0.7 – 0.95

Moderate, repairable damage0.5 – 0.7

Loss of capacity≥0.95

Negligible damage0 – 0.5

Local Response from OpenSees

( )

( )( )

|

||

1FHC,

1FHC,PHCcurrent

βα

βα

θ

θθθ

θθ

⎟⎟⎠

⎞⎜⎜⎝

⎛+−

⎟⎟⎠

⎞⎜⎜⎝

⎛+

=

∑

∑+

+

=

++

=

++

+

n

iipyf

n

iipp

D

Mehanny & Deierlein 2001

Damage IndicesDamage Indices

0 20 40 60 80 100 120 140 160 1800

0.2

0.4

0.6

0.8

1

Time (sec)

Dam

age

Inde

x

TCU08250/50

LP89G04 10/50 1b

TCU0822/50

LP89G0410/50 2

1B1S

1C3

Dθ

DMax

DMaxExc

1B1S

1C3

(d)

(e)

I II

(b)

(c)

1st Floor Beam

Base Column

Moderate Loss of CapacitySignificant Significant

June 4, 2003

12

Damage Index(EDP)

0.5-0.7

0.7-0.9

>0.9

Condition & Consequence(DM)

Minor cracking & spalling

Repair: nothing

Moderate cracking & spalling

Repair: chipping away concrete and repair, grout

Severe cracking & spalling

Repair: not feasible?

Implications(DV)

Moderate cost and shutdown time

Minor cost,No shutdown time

Is repair economically feasible?

EQ #

2EQ

#3

EQ #

4

DamageDamageMeasureMeasure

DecisionDecisionVariableVariable

Engineering Engineering Demand Demand

ParameterParameter

PEER MethodologyPEER Methodology

0.01 0.02 0.03 0.04 0.05 0.06 0.070

0.2

0.4

0.6

0.8

1

1.2

IDRMAX

Sa (g

)

3-Story RCSPerimeter Frame

TCU082-50/50

LP89G04-10/50 1a

LP89G04-10/50 1b

TCU082-2/50

0.01 0.02 0.03 0.04 0.05 0.06 0.070

0.2

0.4

0.6

0.8

1

1.2

IDRMAX

Sa (g

)

3-Story RCSPerimeter Frame

TCU082-50/50

LP89G04-10/50 1a

LP89G04-10/50 1b

TCU082-2/50

OS: Test ConditionsTest Results

Performance & Modeling ImplicationsPerformance & Modeling Implications

Modeling Limitations

OpenSees Model Test Frame

Strength Degrading Hinge ModelsStrength Degrading Hinge Models

Column Spring

Joint Panel SpringBeam Spring

-1.5

-1

-0.5

0

0.5

1

1.5

-8 -6 -4 -2 0 2 4 6 8

Chord Rotation (radians)

Nor

mal

ized

Mom

ent (

M/M

y)

Non-Deteriorated Backbone

My

Cap,pl

Ke

y

Ke

0 0.02 0.04 0.06 0.08 0.1 0.120

0.5

1

1.5

2

2.5

3

3.5

Sa g.

m.(T

=1.0

s) [g

]

Maximum Interstory Drift Ratio

Fiber versus NL Hinge ModelsFiber versus NL Hinge ModelsCode Conforming 4-Story RC FrameFiber Beam-Column Models

Courtesy of C. Haselton

0 0.02 0.04 0.06 0.08 0.1 0.120

0.5

1

1.5

2

2.5

3

3.5

Sag.

m.(T

=1.0

s) [g

]

Maximum Interstory Drift Ratio

Nonlinear Hinge Models

IDRcollapse = 7-12%10/50, Design

2/50, MCE

10% Drift

0 0.005 0.01 0.015 0.02 0.0250

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

Sa g.

m. (g

)

Peak Story Drift Ratio

Lumped Plasticity ModelFiber Model with Uncracked Concrete

70%

Case Study BuildingsCase Study Buildings

3, 6, and 203, 6, and 20--story buildingsstory buildingsComposite beams controlled by strength Composite beams controlled by strength RC columns controlled by SCWBRC columns controlled by SCWBJoints satisfy strength requirements with standard detailsJoints satisfy strength requirements with standard details

Steel BandPlate

Face Bearing

Plate

Joint Ties

6 @ 6.10m = 35.60m

5 @

6.1

m =

30.

5m

2-1/2” Normal Weight Concrete over 3” Metal Deck

A

B

C

D

E

F

1 2 3 4 5 6 7

Design DetailsDesign DetailsColumn SizesColumn Sizes

600x600mm 600x600mm –– 1000x750mm1000x750mm((ρρ = 1.5= 1.5--3%)3%)

Steel BeamsSteel BeamsW450W450--750 (W18750 (W18--W30)W30)

0 0.005 0.01 0.015 0.02 0.025 0.03 0.035 0.04 0.0450

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

IDRMAX

Sa (g

)

6-Story RCS Perimeter Frame

0 0.005 0.01 0.015 0.02 0.025 0.03 0.035 0.04 0.0450

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

IDRMAX

Sa (g

)

6-Story RCS Perimeter Frame

Incremental Dynamic AnalysisIncremental Dynamic Analysis66--Story FrameStory Frame

10/50: Design

2/50: MCE

∆/h ≤2%

<4% at the 2/50 level

Very well behaved at 10/50 level

Similar behavior observed for 3 and 20 story buildings

June 4, 2003

13

Summary ObservationsSummary Observations

Even when designed to test the Even when designed to test the minimum limitsminimum limitsof current building code, the RCS frame showed of current building code, the RCS frame showed excellent behavior under various seismic demands.excellent behavior under various seismic demands.

Composite joints performed wellComposite joints performed wellComposite beam action was maintainedComposite beam action was maintainedPrecastPrecast column splices and beam splices performed wellcolumn splices and beam splices performed well

StrongStrong--Column WeakColumn Weak--BeamBeam

Significance of composite beam actionSignificance of composite beam action

Strength ratio criteria of 1.2 (6/5) is not necessarily a Strength ratio criteria of 1.2 (6/5) is not necessarily a good measure to prevent story mechanisms.good measure to prevent story mechanisms.

Summary Observations, contSummary Observations, cont’’dd

NL Fiber Analysis accurate up to 3% drift ratioNL Fiber Analysis accurate up to 3% drift ratio

Accuracy degrades above 4% due to degradation effects Accuracy degrades above 4% due to degradation effects that are not captured in modelthat are not captured in model

Motivates use of degrading spring type models for >3%Motivates use of degrading spring type models for >3%

Importance of appropriate ground motion selection Importance of appropriate ground motion selection and scalingand scaling

Full system versus subassembly testingFull system versus subassembly testingDamage in the slab and studsDamage in the slab and studs

Severity of local bucklingSeverity of local bucklingOverestimated by typical Overestimated by typical

subassembly testssubassembly tests

Future Research & DevelopmentFuture Research & Development

Develop more costDevelop more cost--effective effective erection/construction methods (especially for erection/construction methods (especially for lowlow--rise)rise)

Improved models to simulate large deformations Improved models to simulate large deformations (including strength/stiffness degradation)(including strength/stiffness degradation)

Comprehensive performanceComprehensive performance--based assessmentbased assessment

Continue to innovate new systemsContinue to innovate new systems

Outline of PresentationOutline of Presentation

Background & ApplicationsBackground & Applications

Composite RCS BeamComposite RCS Beam--Column JointsColumn Joints

Large Scale Composite RCS Frame TestLarge Scale Composite RCS Frame Test

Design/Construction/TestingDesign/Construction/TestingAnalysis and InterpretationAnalysis and Interpretation

The New FrontierThe New Frontier

Nanjing Financial Center

67 Story (339/450M) - 2007

Composite/Hybrid System

SOM

Belt Truss

Perimeter Moment Frame

Steel Braced Frame and Shear Wall

Belt Truss

Belt Truss


• Concrete-Encased Steel Composite Column

• Concrete Core with Encased Steel Columns

• Composite Metal Deck Concrete Floor Slab with Structural Steel Framing

• Concrete Beam and Slab within the Core

June 4, 2003

14

Composite/Hybrid Framing LG Beijing (2005)SOM + local partners

Zhengzhou Tower55 stories (280m) - 2009

Dual system: RC Core & Composite Perimeter Frame

SOM

Concrete Core


32 Perimeter sloping columns per story

Column Diameter 750 – 1150 mm

Encased Steel Section: As = 6.5 % - 8%

Steel Reinforcement: Ar = 2.8% - 3.5%

High Density = Viable Community transportation – services – construction economics

e.g., New San Francisco SkylineInnovations Closer to Home?

Thank you!

Questions ??

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