ddbd fundamentals

RELUIS Linea di ricerca NRELUIS Linea di ricerca N.4.4JulyJuly 2007 Meeting2007 Meeting

RomaRoma3 Luglio 20073 Luglio 2007

EUCENTRE Univeris delgistudi di Pavia

12 unit12 unit di ricercadi ricercaTask Argomento UR 1 Principi, aspetti generali, azione Pavia

2 Strutture in calcestruzzo, a telaio Bologna 3 Strutture in calcestruzzo, a pareti e

miste Ferrara

4 Strutture prefabbricate Brescia

5 Struttura in muratura Genova 6 Strutture in acciaio Napoli 7 Strutture miste acciaio calcestruzzo Benevento 8 Strutture in legno Trento 9 Ponti esistenti e di nuova costruzione Milano Poli 10 Strutture sismicamente isolate Basilicata 11 Fondazioni superficiali e profonde Milano Poli 12 Strutture di sostegno Perugia

Review of programme LINEA IVReview of programme LINEA IV11 ANNOANNO 22 ANNOANNO 33 ANNOANNO

DefinitionDefinition of of generalgeneral aspectsaspectsDefinitionDefinition of of specificspecific aspectsaspectsSelectionSelection of case of case studiesstudiesDesign Design usingusingtraditionaltraditionalmethodsmethodsDesign using Design using displacementdisplacement--based methodsbased methodsNonNon--linear timelinear time--history analyseshistory analysesIdentification and Identification and discussion of discussion of issuesissuesSpecificSpecificimprovementsimprovements totothe the displacementdisplacementbasedbased methodmethodReRe--designdesign and and verificationverificationDevelopmentDevelopment of of specificspecificguidelinesguidelinesDevelopment of a Development of a model code and model code and general general commentarycommentary

me Fu F Fn rKi he Ki Ke y d

(a) SDOF Simulation (b) Effective Stiffness Ke

1 2 3 4 5 6Displacement Ductility

0

20

40

60

D

a

m

p

i

n

g

(

%

)

0 1 2 3 4 5Period (seconds)

0

0.1

0.2

0.3

0.4

0.5

D

i

s

p

l

a

c

e

m

e

n

t

(

m

)

5%

10%

15%

20%

30%

d

Te

Elasto-Plastic

Steel Frame

Concrete Frame

Unbonded Prestressing

(c) Equivalent damping vs. ductility (d) Design Displacement Spectra

DDBD fundamentalsDDBD fundamentals

Sviluppo del progetto Sviluppo del progetto

Strutture a telaio in c.a. a differente Strutture a telaio in c.a. a differente numero di piani e campate (in numero di piani e campate (in particolare, da 1 a 6 piani e da 1 a 3 particolare, da 1 a 6 piani e da 1 a 3 campate);campate);

I materiali sono quelli comunemente I materiali sono quelli comunemente utilizzati nella pratica corrente utilizzati nella pratica corrente (calcestruzzo Rck 300 ed acciaio (calcestruzzo Rck 300 ed acciaio FeFe b b 44 k;44 k;

1.1. STRUTTURE CONSIDERATESTRUTTURE CONSIDERATE(progettate secondo la procedura DDBD)(progettate secondo la procedura DDBD)

Analisi dinamiche non lineariAnalisi dinamiche non lineariTelaio 36 Telaio 36 -- Sintesi dei risultatiSintesi dei risultati

0 0.5 1 1.5 2 2.5 3 3.5 40

1

2

3

4

5

6

Drift di piano [%]

n piano Inviluppo drift massimi

Sismi tipo 2 - ag = 0.35

Sismi tipo 1.1 - ag = 0.35


Sismi con Te>4s - ag = 0.35


0 50 100 150 200 250 3000

200

400

600

800

1000

1200

1400

1600

1800

2000

Spostamento orizzontale [mm]

altezza della struttura [cm] Inviluppo spostamenti massimi assoluti




Sismi con Te>4s - ag = 0.35


Nelle due figure seguenti sono sovrapposti i valori medi degli inviluppi degli spostamenti e degli interstory drift ottenuti per 4 diversi gruppi di sismi.

ResearchResearch UnitUnit 3: RC 3: RC WallsWalls & & MixedMixed

20 storey case study wall 20 storey case study wall structure examined.structure examined.

ForceForce--Based Design and Based Design and Displacement Based Design Displacement Based Design undertaken.undertaken.

NonNon--linear timelinear time--history history analyses undertaken to analyses undertaken to consider performance.consider performance.

Capacity design implications Capacity design implications considered.considered. Snellezza del muro h/l = 10,7

RU 3: Risultati RU 3: Risultati -- FBDFBD

0

10

20

30

40

50

60

70

0 10000 20000 30000 40000 50000

A

l

t

e

z

z

a

[

m

]

Momento [kNm]

An. Dinamica (3 acc. Naturali)An. Dinamica (7 acc. Naturali)An. Dinamica (3 acc. Artificiali)An. Dinamica (7 acc. Artificiali)Approccio agli spostamentiAmplificazione dinamica

0

10

20

30

40

50

60

70

0 1000 2000 3000 4000 5000

A

l

t

e

z

z

a

[

m

]

Taglio [kN]

An. Dinamica (3 acc. Naturali)An. Dinamica (7 acc. Naturali)An. Dinamica (3 acc. Artificiali)An. Dinamica (7 acc. Artificiali)Approccio agli spostamentiAmplificazione dinamica

0

5

10

15

20

25

1 2 3 4 5 6 7

V

a

l

o

r

i

d

i

d

u

t

t

i

l

i

t

[

-

]

Accelerogrammi artificialiDuttilit richiesta Duttilit richiesta media Duttilit disponibile

Confronto tra la duttilit richiesta dalla serie di 7 accelerogrammi artificiali, la duttilit richiesta media e la duttilit

disponibile calcolata con approccio alle forze per CDA

FBD drifts not reported!!!

RU 3: Risultati RU 3: Risultati -- DBDDBD

02468

1012141618

1 2 3 4 5 6 7V

a

l

o

r

i

d

i

d

u

t

t

i

l

i

t

[

-

]

Accelerogrammi artificialiDuttilit richiesta Duttilit richiesta media Duttilit disponibile

Confronto tra la duttilit richiesta dalla serie di 7 accelerogrammi artificiali, la duttilitrichiesta media e la duttilit disponibile calcolata con approccio agli spostamenti

RU 3: CONFRONTI CON DIVERSI PROGRAMMI DI RU 3: CONFRONTI CON DIVERSI PROGRAMMI DI CALCOLOCALCOLO

Again design driftappears to bearound 1.5%

Definition of typical Italian precast concrete building layoutsDefinition of typical Italian precast concrete building layoutsThree different case studies:Three different case studies:

One storey PC building One storey PC building with with double teedouble tee roof roof elementselements

One storey PC building One storey PC building with with omegaomega roof roof elementselements

One storey PC building One storey PC building with precast concrete with precast concrete columns and long span columns and long span wood beamswood beams

7

5

0

0,00 m

8,40 m1.1.

2.2.

3.3.

ResearchResearch UnitUnit 4: 4: PrePre--castcast structuresstructures

M=Me

h=he

d

Ke, Ke,

d

h=he

M=Me

Kfoundation

Kfoundation

M=Me

h=he

d

Ke, Ke,

d

h

M

Kfoundation

Me

he

1.1.

3.3.

2.2.

4.4.

RESEARCH PHASE DEFINITION

Columns fixed at the base and pinned at the top, the foundation flexibility is not taken into account.

As in phase 1 but considering the effect of foundation flexibility

Take into account the different types of base connection (pocket foundation, grouted sleeves); foundation flexibility taken into account

Considering the effect of changing the inflection point along the column due to the presence of column to beam connections.

Unit di ricerca N.4STRUTTURE PREFABBRICATE

Prof. Paolo RIVAIng. Andrea BELLERI

COLUMN TO FOUNDATION CONNECTIONS

40Section B-B

4

0

9

9

2 9

8

9

St. 16/10 L=3306

10 22 L=7218 L=3719

22 L=19526 L=171

7

8

St. 16/10 L=250

St. 8/10 L=1662

5

8 L=1304

PF8

8

2

4

6

GroutEMACO S55

B

5

B

7

2

8

PF Force-Drift

-100

-75

-50

-25

0

25

50

75

100

-8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8

Drift (%)

L

a

t

e

r

a

l

f

o

r

c

e

(

k

N

)

Theoretical yield

P-

Planned to use experimental results to calibrate the parameters of the hysteresis rule that will be used in the Finite Element analyses to validate the DDBD procedure .



FUTURE EFFORTSFUTURE EFFORTS1. Define a parametric procedure to determine the true column

point of inflection (due to the presence of top connections).

2. Model the behaviour of different types of column to foundation connection.

3. Take into account foundation flexibility.

4. Define the DDBD procedure to take into account different column to base connection types and validate it by means of time history analyses.

5. Analyse the other case studies.

6. Continue the experimental survey.



ResearchResearch UnitUnit 5: 5: MasonryMasonry structuresstructures

Displacement and energy dissipation considered.Displacement and energy dissipation considered. Case study structures under examination.Case study structures under examination.

RU5: Case RU5: Case StudyStudy structurestructure 1 1 New New ConstructionConstruction

2060

1

2

0

0

PLAN (ground storey)

4

3

0

3

3

0

3

3

0

3

3

0

Principal elevation

RU5: Case RU5: Case StudyStudy structurestructure 2 2 ExistingExisting ConstructionConstruction

Structure is a section of an existing solid block Structure is a section of an existing solid block masonry building.masonry building.

Building has undergone changes with time and Building has undergone changes with time and possesses several weak elements and irregular possesses several weak elements and irregular characteristics.characteristics.

(h sotto trave=312)

a

(h =345)(h sotto trave=324)

3

3

0

1

8

2

1

1

0

1

8

1

CAMERA

203

129

a=14

+0.33

213108

1

7

9

1

1

2

(h =345)(h sotto trave=324)

CAMERA

1

7

7

1

1

0

(h =350)CAMERA

102

208

210

1 08

CAMERA (h putrella=0000)(h voltino=00000)

127

203

2

6

0

2

2

5

97CAMERA

(h sotto trave=314)(h =340)

209

2

9

8

1

2

0

CAMERA

(h sotto trave=315(h =340)

a

ANDRONE(h chiave=348)(h imposta=291)

3

2

0

2

0

0

(h trave=300)

CAMERA (h =325)

0.00

p= 30

a= 17.5

2

2

3

1

1

7

CAMERA (h chiave=346)(h imposta=244)

1

1

0

2

6

0

128

236

+0.26

PLAN (ground storey)

180180 360 200230

1150

1

1

6

0

3

0

5

4

7

0

3

8

5

2

3

0

2

3

0

2

3

0

Elevation of structural wallTransverse section

ResearchResearch UnitUnit 6: Steel 6: Steel structuresstructures

Various displacement considerations and relations have Various displacement considerations and relations have been developed for different frame configurations.been developed for different frame configurations.

A trial DBD method has been developed for bucklingA trial DBD method has been developed for buckling--restrained brace (BRB), moment resisting frame (MRF) restrained brace (BRB), moment resisting frame (MRF) type structures and now concentrically braced frame (CBF) type structures and now concentrically braced frame (CBF) structures. structures.

Recent work has concentrated on design of CBF systems.Recent work has concentrated on design of CBF systems. 5 & 105 & 10--storey case study structures have been designed storey case study structures have been designed

and methodology performance assessed.and methodology performance assessed.

RU6: CBF RU6: CBF considerationsconsiderations

Compression brace buckling

Tension brace yieldingUltimate state (max compression brace ductility)

Possible target pointVb

ueff

Individual brace response:

comp

tens

Typical Pushover

2.4 8.3F = +c

r a b = +

( )1 2.4 8.32 2

c F

y

= = +

EF

rKL y =

RU6: Displacement contributionsRU6: Displacement contributions

Storey drift components: column Storey drift components: column axial deformations, brace axial axial deformations, brace axial deformations and beam middeformations and beam mid--span span deflection.deflection.

r l r li,d i,d br,i,d b,i,d c,i,d c,i,d

i,d i ii i

22 2

v v vtg tg

L sen h

+= + + +

r lb,i,d c,i,d c,i,d 2

br,i,d i i,d yi

22

vsen

h ++ + =

Relation between strain quantities Relation between strain quantities and brace ductility.and brace ductility.

RU6: Case study RU6: Case study applicationsapplications

3500

3500

3500

3500

4000

3500

3500

3500

3500

3500

0

200

400

600

800

1000

1200

0 0.1 0.2 0.3 0.4 0.5ud (m)

V

b

(

k

N

)

Design

Pushover with brittle braces

Actual pushover

10 storey structure10 storey structureResults for accurate Results for accurate

iterative methoditerative method

0123456789

10

0 0.1 0.2 0.3 0.4 0.5u i (m)

F

l

o

o

r

TargetRHA Average2s_R12s_R22s_R32s_R42s_R52s_R62s_R7

Tension

0123456789

1011

-15 -13 -11 -9 -7 -5 -3 -1 1 3 5 7 9 f

F

l

o

o

r

Target

Capacity

RHA

Compression

RU6: Case study RU6: Case study applicationsapplications

3500

3500

3500

3500

4000

3500

3500

3500

3500

3500

10 storey structure10 storey structureResults for simplified Results for simplified

methodmethod

0100200300400500600700800900

1000

0 0.05 0.1 0.15 0.2 0.25ueff (m)

V

b

(

K

N

)

Design

Analysis

0123456789

10

0 0.1 0.2 0.3 0.4 0.5u i (m)

F

l

o

o

r

TargetRHA Average2s_R12s_R22s_R32s_R42s_R52s_R62s_R7

Tension

0123456789

1011

-15 -13 -11 -9 -7 -5 -3 -1 1 3 5 7 9 f

F

l

o

o

r

Target

Capacity

RHA

Compression

Pushover with real sections and residual strength for compression

diagonals at the design displacements

Research Unit 7: Composite Research Unit 7: Composite StructuresStructures

Case study structures described.Case study structures described. Force basedForce based--design carried out. Intended to verify design design carried out. Intended to verify design

using displacementusing displacement--based assessment.based assessment. 3D structure modelled in SAP2000.3D structure modelled in SAP2000. Parameters expected to influence behaviour of structures Parameters expected to influence behaviour of structures

identified.identified.

RU7: Case study structuresRU7: Case study structures

9-storeys of 3.5m (ground storey 4m)

IPE 450

IPE 450

IPE 450

IPE 450

IPE 450

IPE 450

IPE 450

IPE 450

IPE 450IPE 450 IPE 450 IPE 450 IPE 450

IPE 450 IPE 450 IPE 450 IPE 450

IPE 450 IPE 450 IPE 450 IPE 450

IPE 450 IPE 450 IPE 450 IPE 450

IPE 450 IPE 450 IPE 450 IPE 450

IPE 450 IPE 450 IPE 450 IPE 450

IPE 450 IPE 450 IPE 450 IPE 450

IPE 450 IPE 450 IPE 450 IPE 450

IPE 450 IPE 450 IPE 450 IPE 450

0,00

+ 4,00

+ 7,50

+ 11,00

+ 14,50

+ 18,00

+ 21,50

+ 25,00

+ 28,50

+ 32,00

H

E

B

2

8

0

H

E

B

2

8

0

H

E

B

3

2

0

H

E

B

3

2

0

H

E

B

3

2

0

H

E

B

3

2

0

H

E

B

3

2

0

H

E

B

3

2

0

H

E

B

3

2

0

H

E

B

3

2

0

H

E

B

2

8

0

H

E

B

2

8

0

H

E

B

3

2

0

H

E

B

3

2

0

H

E

B

2

8

0

H

E

B

3

2

0

H

E

B

3

2

0

H

E

B

2

8

0

H

E

B

3

2

0

H

E

B

3

2

0

H

E

B

2

8

0

H

E

B

3

2

0

H

E

B

3

2

0

H

E

B

2

8

0

H

E

B

3

2

0

H

E

B

3

2

0

H

E

B

2

8

0

H

E

B

3

2

0

H

E

B

3

2

0

H

E

B

2

8

0

H

E

B

3

2

0

H

E

B

3

2

0

H

E

B

2

8

0

H

E

B

3

2

0

H

E

B

3

2

0

H

E

B

2

8

0

H

E

B

3

2

0

H

E

B

3

2

0

H

E

B

2

8

0

H

E

B

3

2

0

H

E

B

3

2

0

H

E

B

2

8

0

H

E

B

3

2

0

H

E

B

3

2

0

H

E

B

2

8

0

H

E

B

3

2

0

H

E

B

3

2

0

H

E

B

2

8

0

H

E

B

3

2

0

H

E

B

3

2

0

H

E

B

2

8

0

H

E

B

3

2

0

H

E

B

3

2

0

H

E

B

2

8

0

3

,

5

0

3

,

5

0

3

,

5

0

3

,

5

0

3

,

5

0

3

,

5

0

3

,

5

0

3

,

5

0

4

,

0

0

3

,

4

0

2

,

9

0

2

,

9

0

2

,

9

0

2

,

9

0

2

,

9

0

2

,

9

0

2

,

9

0

2

,

9

0

31,00

7,006,005,006,007,00

3

2

,

0

0

Moment resisting frame in longitudinal direction

HE B 320HE B 320HE B 320HE B 320

HE B 320HE B 320HE B 320HE B 320

HE B 320

HE B 320

HE B 320

HE B 280 HE B 280

IPE 450

IPE 450

IPE 450

IPE 450

IPE 450

I

P

E

3

0

0

I

P

E

3

0

0

I

P

E

3

0

0

I

P

E

3

0

0

I

P

E

3

0

0

I

P

E

3

0

0

I

P

E

3

0

0

I

P

E

3

0

0

I

P

E

3

0

0

I

P

E

3

0

0

I

P

E

3

0

0

I

P

E

3

0

0

I

P

E

3

0

0

I

P

E

3

0

0

I

P

E

3

0

0

I

P

E

3

0

0

I

P

E

3

0

0

I

P

E

3

0

0

I

P

E

3

0

0

I

P

E

3

0

0

I

P

E

3

0

0

HE B 280HE B 320HE B 320HE B 320HE B 320

HE B 280HE B 320HE B 320HE B 320HE B 320HE B 280

HE B 280HE B 320HE B 320HE B 320HE B 320

HE B 280HE B 280

IPE 450 IPE 450 IPE 450 IPE 450

IPE 450 IPE 450 IPE 450 IPE 450

IPE 450 IPE 450 IPE 450 IPE 450

IPE 450 IPE 450 IPE 450 IPE 450

IPE 450 IPE 450 IPE 450 IPE 450I

P

E

3

0

0

I

P

E

4

5

0

I

P

E

4

5

0

Y1 Y2 Y3 Y4 Y5 Y6

X1

X2

X3

X4

X5

7,00 6,00 5,00 6,00 7,00

31,00

6

,

0

0

6

,

0

0

6

,

0

0

6

,

0

0

2

4

,

0

0

Y

X

Pianta piano tipo

PLAN

H

E

B

2

8

0

H

E

B

2

8

0

H

E

B

2

8

0

H

E

B

2

8

0

H

E

B

2

8

0

H

E

B

2

8

0

H

E

B

2

8

0

H

E

B

2

8

0

H

E

B

2

8

0

H

E

B

2

8

0

H

E

B

2

8

0

H

E

B

2

8

0

H

E

B

2

8

0

H

E

B

2

8

0

H

E

B

2

8

0

H

E

B

2

8

0

H

E

B

2

8

0

H

E

B

2

8

0

168,3

x 12,5 168,3 x 12,5

168,3

x 12,5 168,3 x 12,5

168,3

x 12,5 168,3 x 12,5

168,3

x 12,5 168,3 x 12,5

168,3

x 12,5 168,3 x 12,5

168,3

x 12,5 168,3 x 12,5

168,3

x 12,5 168,3 x 12,5

168,3

x 12,5 168,3 x 12,5

168,3 x 12,5168,

3 x 12

,5

H

E

B

3

2

0

H

E

B

3

2

0

H

E

B

3

2

0

IPE 300 IPE 300

IPE 300 IPE 300

IPE 300 IPE 300

IPE 300 IPE 300

IPE 300 IPE 300

IPE 300 IPE 300

IPE 300 IPE 300

2

,

9

0

2

,

9

0

2

,

9

0

2

,

9

0

2

,

9

0

2

,

9

0

2

,

9

0

2

,

9

0

3

,

4

0

3

,

5

0

3

,

5

0

3

,

5

0

3

,

5

0

3

,

5

0

3

,

5

0

3

,

5

0

3

,

0

5

3

,

0

5

3

,

0

5

3

,

0

5

3

,

0

5

3

,

0

5

3

,

0

5

IPE 300

IPE 300

IPE 450

IPE 450

IPE 450

IPE 450

IPE 450

IPE 450

IPE 450

IPE 450

IPE 450

IPE 450

IPE 450

IPE 450

IPE 450

IPE 450

IPE 450

IPE 450

IPE 450

IPE 450

IPE 300

IPE 300

H

E

B

3

2

0

H

E

B

3

2

0

H

E

B

3

2

0

H

E

B

3

2

0

H

E

B

3

2

0

H

E

B

3

2

0

H

E

B

3

2

0

H

E

B

3

2

0

H

E

B

3

2

0

H

E

B

3

2

0

H

E

B

3

2

0

H

E

B

3

2

0

H

E

B

3

2

0

H

E

B

3

2

0

H

E

B

3

2

0

H

E

B

3

2

0

H

E

B

3

2

0

H

E

B

3

2

0

H

E

B

3

2

0

H

E

B

3

2

0

H

E

B

3

2

0

H

E

B

3

2

0

H

E

B

3

2

0

H

E

B

3

2

0

+ 32,00

+ 28,50

+ 25,00

+ 21,50

+ 18,00

+ 14,50

+ 11,00

+ 7,50

+ 4,00

0,00

4

,

0

0

3

,

5

0

3

,

5

5

3

,

0

5

6,00 6,00 6,00 6,00

3

2

,

0

0

24,00

Braced frames in transverse direction

RU7: General design progressRU7: General design progress Case study structures dimensioned using a forceCase study structures dimensioned using a force--based based

design approach.design approach.

HE B 280

280

2

8

0

10,5

1

8

2

4

4

1

8

R25

12,5168

,3

Profilo circolare cavo formato a caldo

IPE 300

1

0

,

7

7,1

3

0

0

150

2

7

8

,

6

1

0

,

7

R15

2

0

,

5

2

7

9

2

0

,

5

300

3

2

0

HE B 320

IPE 450

1

4

,

6

4

2

0

,

8

1

4

,

6

4

5

0

190

600

150

61,5 88,5

5

5

Lamiera grecata tipoA 55/P 600 HI-BOND

t = 1.5 mm Fe 430 hP =55 mm

Rete elettrosaldata 10/25

600

5

5

1

5

0

Solaio compostocalcestruzzo-lamiera grecata

Research Unit 8: Timber StructuresResearch Unit 8: Timber Structures

Case study structures selected & described. Case study structures selected & described. Characteristics of timber joint studied Characteristics of timber joint studied important important

deformation parameters obtained. Design deformation parameters obtained. Design displacement considerations made.displacement considerations made.

DisplacementDisplacement--based design methodology based design methodology developing.developing.

MonteMonte--Carlo simulations to probabilistically Carlo simulations to probabilistically evaluate performance of case study structures evaluate performance of case study structures currently underway.currently underway.

RU8: Portal frame case studyRU8: Portal frame case study

Radial joint behaviour studied intended that joints yield.

RU8: Displacement considerationsRU8: Displacement considerations Yield displacement composed of deformations from joint Yield displacement composed of deformations from joint

+ frame. This is added to acceptable plastic deformation + frame. This is added to acceptable plastic deformation to give design displacement.to give design displacement.

Yield characteristics of single bolt control system yield Yield characteristics of single bolt control system yield dispdisp.. Strength of joint can be controlled (without significantly Strength of joint can be controlled (without significantly

changing yield displacement) by changing number of bolts.changing yield displacement) by changing number of bolts.

RU8: Factors influencing target displacementsRU8: Factors influencing target displacements

Research Unit 9: New & existing Research Unit 9: New & existing bridgesbridges

DDBD of regular concrete bridges. Comparison with force DDBD of regular concrete bridges. Comparison with force based design. Verification with time history analyses.based design. Verification with time history analyses.

DDBD of irregular concrete bridges. Comparison with force DDBD of irregular concrete bridges. Comparison with force based design. Verification with time history analyses.based design. Verification with time history analyses.

DDBD of long span concrete bridges with limited ductile DDBD of long span concrete bridges with limited ductile piers and with/without inpiers and with/without in--plane movement joints. plane movement joints. Comparison with force based design. Verification with time Comparison with force based design. Verification with time history analyses.history analyses.

Activities of RU9 in the second yearActivities of RU9 in the second year

Parametric study: regular bridges

H=7.5 m, 10 m, 12.5 m, 15 m

Activities of RU9 in the second yearActivities of RU9 in the second yearCalcestruzzo

Materialsfc 40 [MPa] Resistenza a compressione Ec 30000 [MPa] Modulo elastico Wc 25 [kN/m3] Peso specifico Acciaio fy 455 [MPa] Sforzo di snervamento Es 200000 [MPa] Modulo elastico dbl 43 [mm] Diametro barre longitudinali

Abutmens: elastic behaviour, stiffness K=75000 kN/m, damping 8%, displacement limit 100 mm

Deck: Iyy=44 m4 Pier diameter: from 2 m to 2.7 m

Pier design displacement limit:4% of drift

Some results: regular bridge

SDOF parametersH [m] 7.5 10 12.5 15sys [%] 10.5 8.5 7.5 6.4Dd [m] 0.24 0.32 0.399 0.479Meff [ton] 2909 2948 2994 3039Teff [s] 1.4 1.73 2.08 2.38Keff [kN/m] 59005 38754 27313 21109VB [kN] 14180 12394 10908 10101SS [%] 31.4 45.2 62.7 79.3

H = 7.5 mA1 P1 P2 P3 A2

H[m] - 15.00 7.50 15.00 -D[m] - 2.50 2.50 2.50 -Mass[ton] 357 928 986 928 357D - 1.27 6.99 1.27 - [%] 8.00 7.66 18.05 7.66 8.00V [kN] 2223 2432 4864 2432 2223M [kN*m] - 36477 36477 36477 -Keff [kN/m] 75000 11825 16224 11825 75000

H = 10.0 mA1 P1 P2 P3 A2


H =12.5 mA1 P1 P2 P3 A2


H = 15.0 mA1 P1 P2 P3 A2


Displacement Pattern Limit Limit Yield

0.0

0.2

0.4

0.6

0.8

1.0

1.2

0 20 40 60 80 100 120 140 160 180Position [m]

D

i

s

p

l

a

c

e

m

e

n

t

s

[

m

]

0.0

0.2

0.4

0.6

0.8

1.0

1.2

0 20 40 60 80 100 120 140 160 180Position [m]

D

i

s

p

l

a

c

e

m

e

n

t

s

[

m

]

0.0

0.2

0.4

0.6

0.8

1.0

1.2

0 20 40 60 80 100 120 140 160 180Position [m]

D

i

s

p

l

a

c

e

m

e

n

t

s

[

m

]

0.0

0.2

0.4

0.6

0.8

1.0

1.2

0 20 40 60 80 100 120 140 160 180Position [m]

D

i

s

p

l

a

c

e

m

e

n

t

s

[

m

]

Elastic Modal Superposition witha and w/o R Effective and Modified Modal Superposition

H = 7.5 m

H = 10.0 m

H =12.5 m

H = 15.0 m

Design THA Average EMS with R EMS no R EffMS MMS

0 40 90 140 190 240 2800

1

2

3

4x 105

Position [m]

M

o

m

e

n

t

[

k

N

*

m

]

0 40 90 140 190 240 2800

1

2

3

4x 105

Position [m]

M

o

m

e

n

t

[

k

N

*

m

]

0 40 90 140 190 240 2800

1

2

3

4x 105

Position [m]

M

o

m

e

n

t

[

k

N

*

m

]

0 40 90 140 190 240 2800

1

2

3

4x 105

Position [m]

M

o

m

e

n

t

[

k

N

*

m

]

0 40 90 140 190 240 2800

1

2

3

4x 105

Position [m]

M

o

m

e

n

t

[

k

N

*

m

]

0 40 90 140 190 240 2800

1

2

3

4x 105

Position [m]

M

o

m

e

n

t

[

k

N

*

m

]

0 40 90 140 190 240 2800

1

2

3

4x 105

Position [m]

M

o

m

e

n

t

[

k

N

*

m

]

0 40 90 140 190 240 2800

1

2

3

4x 105

Position [m]

M

o

m

e

n

t

[

k

N

*

m

]

Better moment prediction when using effective-stiffness modal superposition (EffMS)

Some results: irregular bridge

Long span concrete bridges with limited ductile piers and with/without in-plane movement joints

Bridge dimension and shape from real condition limited ductility, significant irregularities in span and pier heights.

Some different assumption in comparison previous analyses: moment capacities are different at different pier bases. The distribution of shear force is estimated by:

P,iP,i

P,i

VH

P,iP,i

P,i

VH (Ductile column)

(Elastic column) P,i P ,iP ,i

P ,i

VH

P,i=moment capacity of ith pier as a percentage of the moment capacity of critical pier.

discretized pier elements with lumped masses have to be considered

Secant stiffness from:

23N 1 N 1i i i

c sec top B ii 1 i 1

F h hHE I V F H3 2 3

= =

= +

3D fiber element model for non linear time-history analyses

Software: OPENSEESversion 1.7.3 (Fenves et al 2006)

A Revised Effective Modal Superposition is applied: effective modal superposition with 5% damped acceleration spectrum is used to estimate the abutment shear and deck transverse moment. effective modal superposition with design displacement spectrum scaled down by appropriate system damping is used to calculate the flexural moment demand at the potential plastic hinge locations (when higher modes are equally important as first inelastic mode)

Deck properties

Pier properties

Substitute structure parameters

Some results: bridge with in-plan movement joint

X-axis Y-axis Z-axis19.24 10-set 297.44 647.4

Cross sectional area (m2)

Second moment of area (m4) about local

sys (%) sys (m) Msys (Mt) M (%)8.93 0.726 10230 39.08

Tsys(s) Ksys (s) VB (kN) SS (%)4 25250 18330 12.70%

Abut 1 Pier 1 Pier 2 Pier 3 Pier 4 Abut 2M

(MNm) --- 570 470 440 390 ---

D (rad/m) --- 0.81x10-3 1.12x10-3 0.63x10-3 0.55x10-3 --- (%) --- 1.6 1.0 1.0 1.0 ---

Y-axis Z-axis thickness4 7 1.2 20.64

X-axis Y-axis Z-axis10-set 101.36 35.76

Dimension (m) along local Sectional area (m2)

Second moment of area (m4)

Abut 1 Pier 1 Pier 2 Pier 3 Pier 4 Abut 2V (kN) 4850 29500 22500 16600 19400 3100

MN (MNm) --- 1355 960 700 880 --- (%) --- 4 2.5 2.5 2.5 ---

Revised effective modal superposition results

FBD results

Research Unit 10: Structures with Research Unit 10: Structures with passive control (isolation) devicespassive control (isolation) devices

Tentative displacementTentative displacement--based design methodology based design methodology for both isolated bridges and isolated buildings for both isolated bridges and isolated buildings proposed. proposed.

Building case study structure selected (4Building case study structure selected (4--storey RC storey RC frame), bridge case study structure still being frame), bridge case study structure still being decided on. decided on.

Different isolation systems listed & equivalent Different isolation systems listed & equivalent viscous damping considered.viscous damping considered.

Some issues identified for further study.Some issues identified for further study. Important phases of research listed.Important phases of research listed. Collaboration with other groups not requested. Collaboration with other groups not requested.

0 100 200 300 400 500 600Shear (KN)

0 100 200 300 400 500 600

2nd floor

DDBD ULD TLD JPN SAP 2

4th floor

3rd floor

1st floor

Isolator

Case StudyCase Study

Previous Activities of RU10Previous Activities of RU10Implementation and verification of a DDBD procedure for BIImplementation and verification of a DDBD procedure for BI--

BuildingsBuildingsDiscrepancies between DDBD predictions and NTHA resultsDiscrepancies between DDBD predictions and NTHA results

SAP2000

0

100

200

300

400

500

600

700

1 5 0 2 00 2 5 0 3 00

Target Displacement/Limit Displacement (%)

(

m

m

)

0

100

200

300

400

500

600

7000 5 00 1 000 1 5 00 2 000

40% 60% 100%80%

(

m

m

)Elasto-Plastic system (EP) with r=1.5%

1.1. Rubber Devices (RD)Rubber Devices (RD)

2.2. Added Damping Added Damping RDsRDs (ADRD)(ADRD)

3.3. ElastoElasto--Plastic systems (EP)Plastic systems (EP)

4.4. LeadLead--Rubber Bearings (LRB)Rubber Bearings (LRB)

5.5. SteelSteel--PTFE Sliding Bearings (SB) + RDPTFE Sliding Bearings (SB) + RD

6.6. SB + SMA devices with/out viscous dampers (VD)SB + SMA devices with/out viscous dampers (VD)

7.7. Friction Pendulum Systems (FPS) with/out VDFriction Pendulum Systems (FPS) with/out VD

8.8. SB + Steel Hysteretic Device (SHD)SB + Steel Hysteretic Device (SHD)

SAPi

SAPAV

DDBD

Dt/DlimDDBDULDTLDJPN

SAP

STOREY SHEAR STOREY SHEAR FORCES FORCES

Isolation Isolation SystemsSystems

base displ.floor


Experimental Shaking table and PseudoExperimental Shaking table and Pseudo--Dynamic Tests on different reducedDynamic Tests on different reduced--

scale Models of multiscale Models of multi--storeysstoreys BIBI--BuildingsBuildings

MOTIVATION: observation of appreciable discrepancies in terms of both max. base displacement and max. storey shear forces between DDBD predictions and NTHA results for some Isolation Systems

Evaluation of enhanced equivalent static force

Distributions

Evaluation of enhanced

damping ratios &/or damping

reduction factors

Experimental Experimental

Numerical Numerical

Same iterative procedure as in Same iterative procedure as in BlandonBlandon and Priestley [2005]and Priestley [2005]

FURTHER DEVELOPMENTS OF THE DDBD FURTHER DEVELOPMENTS OF THE DDBD PROCEDURE FOR BIPROCEDURE FOR BI--BUILDINGSBUILDINGS

PROPOSED SOLUTIONS

NTHAsNTHAs of 3of 3--, 5, 5--, 8, 8--storey building Modelsstorey building Modelsequipped with different equipped with different ISsISs (SAP2000)(SAP2000)

BI-buildings with inelastic superstructure


ElastoElasto--Plastic systems (EP)Plastic systems (EP)

SB + SMA devices without viscous dampersSB + SMA devices without viscous dampers

Results of the studyResults of the study

0.00

0.50

1.00

1.50

2.00

5 10 15 20 25 30 35 400

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

0 10 20 30 40 50 60 70

Ashour

Tolis Faccioli

SSN

prEC8

FR-ESP

CHINA

JPN

N-H

Wu Hanson

EC8

Iter. Proc.

optim.i

f

i

f

/

i

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

0 10 20 30 40 50 60 70

AshourTolis FaccioliSSNprEC8FR-ESPCHINAJPNN-HWu HansonEC8optim.r=0r=1.5r=3r=5r=10

f

i (%)0.00

0.25

0.50

0.75

1.00

1.25

1.50

0 10 20 30 40 50 60 70

i

f

/

i

=10

=20

=30

=40

=50

=60

=70

i

f

/

i

i

f

%%

%

%%


ElastoElasto--Plastic systems (EP)Plastic systems (EP) SB + SMA devices without VDSB + SMA devices without VD

Results of the studyResults of the study

0

0.5

1

1.5

2

2.5

3

Dy=10mm, r=1%Dd/Dlim=40%




0

0.5

1

1.5

2

2.5

3

Reviewed DDBD

DDBD

0

0.5

1

1.5

2

2.5

3

Dy=5mm, r=5%b=0.5, FR=10%Dd/Dlim=40%

Dy=5mm, r=3%b=0.3, FR=5%Dd/Dlim=60%

Dy=10mm, r=5%b=0.5, FR=2.5%

Dd/Dlim 80%

Dy=5mm, r=1%b=0.5, FR=2.5%Dd/Dlim=100%

0

0.5

1

1.5

2

2.5

3

Reviewed DDBD

DDBD

DA

Vm

ax(S

AP)

/

Dt

exact predictions

ERROR

0 0.5 1 1.5 2 2.5

S0

S1

S2

S3

Linear (e)

Bilinear (g)

Parabolic (f)

Pi=f( T2/T1, T1/Tf; Tis/Tf )

=

ii

iibi am

amVF

e

e

d

d

c

c

b

b

b

g

g

g

f

f

f

ed

c

a

a

a

0 1 5 3 0 4 5

e

e

d

d

c

c

b

b

b

g

g

g

f

f

fe

d

c

a

a

a

0 1 5 3 0 4 5

e

e

d

d

c

c

b

b

b

g

g

g

f

f

fed

c

a

a

a

0 1 5 3 0 4 5

LDRB PGA=0.54g;Tiso/Tbf=3.56

a: experimentalb: uniform (ITA)c: triangular (ITA/USA)

g: bilinear

S3

S2

S1

kNFSB+SHD

PGA=0.31g;Tiso/Tbf=4.26FSB+SMA

PGA=0.54g;Tiso/Tbf=3.86

d: trapezoidal (JPN)e: linearf: parabolic

S3

S2

S1

S3

S2

S1

90.0

353.0

97.5

Tavola Vibrante

Celle di carico

150.0

90.0

150.0

345.0

Forze statiche equivalenti Forze statiche equivalenti Confronti sperimentaliConfronti sperimentali

Attivit svolta nel corso del secondo anno di ricerca

1. Simulazione numerica delle prove sperimentali eseguite su tavola vibrante presso il PWRI, mediante il codice di calcolo 4GL (Paolucci, 1997)

2. Calibrazione ed utilizzo del modello costitutivo SFCM, allo scopo di creare abachi che descrivano il decadimento della rigidezza e lincremento di smorzamento del sistema terreno - fondazione

Research Unit 11: Deep & shallow foundationsResearch Unit 11: Deep & shallow foundations

Simulazione delle prove sperimentali su tavola vibrante (PWRI)Fondazione modello posta su tavola vibrante, sollecitata con diversi segnali sismici

-0.5-0.25

00.25

0.5

M

/

V

B

5.5 7.5 9.5 11.5 13.5 15.5Time (s)

-0.5-0.25

00.25

0.5

M

/

V

B

Case 2-2

no degr.

degr.

5.5 6 6.5-0.2-0.1

00.10.2

M

/

V

B

observed

simulated

Case 2-2

Simulazione delle prove sperimentali su tavola vibrante (PWRI)

Creazione di abachi mediante il modello SFCM

Obiettivo:Simulazione di prove cicliche, per mettere in evidenza linfluenza di vari parametri progettuali sullandamento delle curve di decadimento della rigidezza e di variazione dello smorzamento

Calibrazione dei parametri del modello:prove sperimentali eseguite ad Ispra (TRISEE, 1998)

Creazione di abachi mediante il modello SFCMAnalisi ed interpolazione dei risultati rigidezza rotazionale

1E-005 0.0001 0.001 0.01 0.1rotazione (rad)

0

0.2

0.4

0.6

0.8

1

K

/

K

0

(

-

)

Vmax/V

La disposizione dei punti dipende unicamente dal fattore di sicurezza

0,000000

0,200000

0,400000

0,600000

0,800000

1,000000

1,200000

0,000100 0,001000 0,010000 0,100000 1,000000

rotazione (rad)

K

/

K

0

maKK += 1

10

0,000000

0,200000

0,400000

0,600000

0,800000

1,000000

1,200000

0,000010 0,000100 0,001000 0,010000 0,100000 1,000000

spostamento u/B (-)

K

T

/

K

T

0

Creazione di abachi mediante il modello SFCMAnalisi ed interpolazione dei risultati rigidezza traslazionale

La disposizione dei punti dipende dal fattore di sicurezza e dal valore di h/B

nbKTKT += 1

10

1E-006 1E-005 0.0001 0.001 0.01spostamento normalizzato u/B (m)

0

0.2

0.4

0.6

0.8

1

K

T

/

K

T

0

(

-

)

Creazione di abachi mediante il modello SFCMAnalisi ed interpolazione dei risultati smorzamento

1E-005 0.0001 0.001 0.01 0.1rotazione (rad)

0

0.2

0.4

0.6

0.8

0.1

0.3

0.5

0.7

s

m

o

r

z

a

m

e

n

t

o

(

-

)

La disposizione dei punti dipende unicamente dal fattore di sicurezza

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0,8

0,9

0,000100 0,001000 0,010000 0,100000 1,000000

rotazione (rad)

s

m

o

r

z

a

m

e

n

t

o

(

-

)

dc +=

Creazione di abachi mediante il modello SFCMVerifica: confronto con i dati sperimentali:

PWRI

Rigidezza rotazionale - sabbia densa (VMAX/V=29.7 - a=5192.13, m=1.02)

0

0,2

0,4

0,6

0,8

1

1,2

0,00001 0,0001 0,001 0,01 0,1 1

rotazione (rad)

K

/

K

0

(

-

)

abacosperimentali

Rigidezza rotazionale - sabbia mediamente addensata (VMAX/V=16.3 - a=653.02, m=0.788)

0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0,8

0,9

1

0,00001 0,0001 0,001 0,01 0,1 1

rotazione (rad)

K

/

K

0

(

-

)

abacosperimentali

Sintesi risultati ottenutiSintesi risultati ottenuti

ValidazioneValidazione su dati da tavola vibrante di un modello semplice per lo su dati da tavola vibrante di un modello semplice per lo studio dellstudio dellinterazione dinamica suolointerazione dinamica suolo--struttura in campo nonstruttura in campo non--linearelineare.

Calibrazione del modello costitutivo SFCM sulla base di prove sperimentali cicliche su modelli di grande scala, e creazione di abachi che descrivano il decadimento della rigidezza e lincremento di smorzamento del sistema terreno - fondazione

Research Unit 12: Retaining StructuresResearch Unit 12: Retaining Structures

Summary of progress for Summary of progress for LineaLinea IVIV

Available literature appears to be well Available literature appears to be well researched.researched.

Some useful DDBD recommendations are Some useful DDBD recommendations are emerging emerging likely that draft model code can likely that draft model code can be formed.be formed.

Book on Book on DisplacementDisplacement BasedBased SeismicSeismicDesign of Design of StructuresStructures

New book New book releasedreleased 2007 2007 withwith a a lotlot of material of material relevantrelevant toto Linea IV.Linea IV.

ChapterChapter 14 14 includesincludes the the basicsbasics of a of a draftdraft code code forforDBD.DBD.

SampleSample PagesPages

Info to be proposed:

Design motions

Performance Criteria

SampleSample PagesPagesInfo to be proposed:

Strain limits

Drift limits

Material Strengths



Design displacement profile for different structural types.

Guidelines for the formation of equivalent SDOF systems



Equivalent viscous damping expressions

Effective period & stiffness approach

Design base shear and equivalent lateral forces.

... e Capacity Design?

LikelyLikely scope of scope of draftdraft model code model code

RC framesRC frames RC walls & frameRC walls & frame--wallswalls PC structures PC structures capanonecapanone UnreinforcedUnreinforced masonry masonry

structuresstructures Steel structures Steel structures MRFsMRFs, ,

CBFsCBFs, BRB frames, BRB frames Composite structures Composite structures --

MRFsMRFs

Timber structures Timber structures capanonecapanone con con nodinodi anulareanulare

Bridges Bridges RC: Regular & RC: Regular & IrregularIrregular

Isolated structures Isolated structures Retaining structures Retaining structures

paratiaparatia a a cuneocuneo Foundation Structures Foundation Structures

piled and pad footingspiled and pad footings

GrazieGrazie

RELUIS Linea di ricerca N.4July 2007 Meeting12 unit di ricercaReview of programme LINEA IVSviluppo del progetto STRUTTURE CONSIDERATE(progettate secondo la procedura DDBD)Research Unit 3: RC Walls & MixedRU 3: Risultati - FBDRU 3: Risultati - DBDRU 3: CONFRONTI CON DIVERSI PROGRAMMI DI CALCOLOResearch Unit 4: Pre-cast structuresResearch Unit 5: Masonry structuresRU5: Case Study structure 1 New ConstructionRU5: Case Study structure 2 Existing ConstructionResearch Unit 6: Steel structuresRU6: CBF considerationsRU6: Displacement contributionsRU6: Case study applicationsRU6: Case study applicationsResearch Unit 7: Composite StructuresRU7: Case study structuresRU7: General design progressResearch Unit 8: Timber StructuresRU8: Portal frame case studyRU8: Displacement considerationsRU8: Factors influencing target displacementsRU8: Factors influencing target displacementsResearch Unit 9: New & existing bridgesResearch Unit 10: Structures with passive control (isolation) devicesSummary of progress for Linea IVBook on Displacement Based Seismic Design of StructuresSample PagesSample PagesSample PagesSample PagesLikely scope of draft model code Grazie

ddbd fundamentals

Documents