Experimental tests on seismic upgrading techniques for RC...

Experimental tests on seismic upgrading Experimental tests on seismic upgrading techniques for RC buildingstechniques for RC buildings

MarchMarch 3030--31,31, 20072007 -- Prague,Prague, Czech RepublicCzech Republic

FF. M. . M. Mazzolani, Mazzolani, Gaetano Della CorteGaetano Della Corte, , E. Barecchia, M. D’AnielloE. Barecchia, M. D’Aniello

DeptDept. of . of StructuralStructural EngineeringEngineeringUniversity of University of NaplesNaples “Federico II”“Federico II”

The BUILDINGThe BUILDING

Prof. F.M. Mazzolani - UNIVERSITY of NAPLES “FEDERICO II”

The BUILDING (The BUILDING (substructuringsubstructuring))


ShapeMemory

Alloy races(SMAB)

Composite Materials(C-FRP)

EccentricBraces

(EB)

Steel Buckling

Restrained Braces(BRB)

Base Isolationwith rubber

bearings(BI)

Lateral Loading Test of the Bare RC Structure

Metal ShearPanels(MSP)

55 6644332211


DynamicDynamic IdentificationIdentification TestsTests

Dynamic shaker (vibrodyne) test


Dynamic Identification TestsDynamic Identification Tests

Falling mass test



Impacting hammer test



Mode Frequency (Hz) Damping (%)

1 1.44 2.7

2 2.20 3.0

3 4.63 2.5

4 5.56 6.3

5 6.85 2.6

Mode 1 Mode 2 Mode 3

Mode 4 Mode 5

TESTTEST on the bareon the bare RC RC structurestructure


Direction of

Loading

SECOND FLOOR

GEOMETRY OF THE STRUCTURE

Direction of Loading

General views of the reacting structure

LOADING AND MEASURING DEVICES

Close-up views of the reacting structure with the load jacksDisplacement

measuring devices


Top-story column mechanism

Close-up views of plastic hinges

PHYSICAL TEST RESULTS




01020304050607080

0 0.05 0.1 0.15 0.2 0.25 0.3Top Displacement (m)

Bas

e Sh

ear (

kN)

Plastic hinge model (SAP 2000)

Experimental results

Fiber model (OpenSEES)

Composite fiber reinforced materialsComposite fiber reinforced materials


General views of the reacting structure

LOADING AND MEASURING DEVICES

Close-up views of the reacting structure with the load jacks

Displacement measuring devices



Global collapse mechanism

Close-up views of plastic hinges at the column bases

PHYSICAL TEST RESULTS: damage pattern


Composite fiber reinforced materialsComposite fiber reinforced materialsPHYSICAL TEST RESULTS: damage pattern

Peeling off at a wrong end detail

Cracking of beams in torsion

Local buckling of free length portions of strips


-200

-150

-100

-50

0

50

100

150

200

-0.04 -0.03 -0.02 -0.01 0 0.01 0.02 0.03 0.04Top Drift Angle (rad)

Bas

e Sh

ear (

kN)

1.91.9

1.01.0


Steel Steel EccentricEccentric BracesBraces (EB)(EB)


-700

-500

-300

-100

100

300

500

700

-0.03 -0.02 -0.01 0 0.01 0.02 0.03Average 1st Story Drift Angle (rad)

Bas

e Sh

ear (

kN)

Steel Steel EccentricEccentric BracesBraces (test #1)(test #1)


No No capacitycapacity--designdesign criterioncriterion appliedapplied

-700

-500

-300

-100

100

300

500

700

-0.015 -0.01 -0.005 0 0.005 0.01 0.015 0.02Average 1st Story Drift Angle (rad)

Bas

e Sh

ear (

kN)


VVjj,,RkRk//VVpp = 1.89= 1.89


-700

-500

-300

-100

100

300

500

700

-0.06 -0.05 -0.04 -0.03 -0.02 -0.01 0 0.01 0.02 0.03Average 1st Story Drift Angle (rad)

Bas

e sh

ear (

kN)


VVjj,,RkRk//VVpp = 2.84= 2.84


0

100

200

300

400

500

600

700

0 2 4 6 8 10 12

Displacement (cm)

Bas

e Sh

ear (

kN)

Bare RC structure

EB - Test n.1

EB - Test n.3

EB - Test n.2

Steel Steel EccentricEccentric BracesBraces ((comparisoncomparison))


8.58.5

5.85.8

7.87.8

1.01.0

Steel BucklingSteel Buckling Restrained Restrained Braces Braces (BRB)(BRB)


-500-400-300-200-100

0100200300400500

-0.015 -0.01 -0.005 0 0.005 0.01 0.015 0.02Average 1st story drift angle (rad)

Bas

e sh

ear (

kN)

Core fracture


Steel BucklingSteel Buckling Restrained Restrained BracesBraces (test #1)(test #1)

-500-400-300-200-100

0100200300400500

-0.02 -0.01 0 0.01 0.02 0.03 0.04 0.05 0.06Average 1st story drift angle (rad)

Bas

e sh

ear (

kN)

Gusset plate buckling

Local failure of the restraining tube


End local

Steel BucklingSteel Buckling Restrained Restrained BracesBraces (test #1)(test #1)

0

100

200

300

400

500

0 2 4 6 8 10 12 14 16 18 20 22 24

Average top displacement (cm)

Bas

e Sh

ear (

kN)

Bare RC structure

BRB - Test n.1

BRB - Test n.2

Test interrupted owing to the achievement of the maximum

allowable core excursionTest interrupted owing to the core fracture


Steel BucklingSteel Buckling Restrained Restrained BracesBraces ((comparisoncomparison))

4.24.2

5.15.1

1.01.0

ComparisonComparison of of resultsresults


0

100

200

300

400

500

600

0 2.5 5 7.5 10 12.5 15 17.5 20 22.5 25Top Displacement (cm)

Bas

e Sh

ear (

kN)

Bare RC structureC-FRPEB 1EB 2EB 3BRB 1BRB 2

4.24.2

5.15.1

1.01.0

8.58.5

5.85.8

7.87.8

1.91.9 FRP

Bare RC

BRB

EB


Base IsolationBase Isolation


Base Base IsolationIsolation


Base IsolationBase Isolation

25

-10

-5

0

5

10

15

20

Time32,50 2,5 5 7,5 10 12,5 15 17,5 20 22,5 25 27,5 30

0,15

-0,15

-0,1

-0,05

0

0,05

0,1

Time (s)32,50 5 10 15 20 25 30

Experimental tests on seismic upgrading techniques for RC...

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