COST C26

Urban Habitat Constructions under Catastrophic Events

WG2 Earthquake Resistance

Innovative seismic protection technologies

and case studies

General Report by:

Michael Kaliske

Technische Universität Dresden, Germany

Alberto Mandara

Second University of Naples – Italy

Need for high performance under seismic action;

Necessity to comply with severe regulations; Optimisation of the structural behaviour; Improvement of the structural response

under exceptional (catastrophic) loading conditions (increase of the structural robustness).

BASIS OF THE USE OF “SPECIAL” SOLUTIONS IN SEISMIC DESIGN

Earthquake of exceptional intensity; Earthquake occurring in a no-seismic area; Earthquake striking a building designed

without complying with seismic regulation; Earthquake striking a degraded/damaged

building; Earthquake striking a historical or

monumental building; …….. …….. any other unpredictable event.

WHAT MEANS “CATASTROPHIC SEISMIC EVENTS”?

Lightness; Reliability; Ease of monitoring, inspection and maintenance; No-added stiffness; Ease of substitution; Reversibility;

MAIN REQUISITES OF THE PROTECTION SYSTEM

These features involve advanced strategies to be followed, consisting of:

1. Use of innovative materials;2. Use of seismic control techniques.

Main Topics faced within Cost C26 WG2 “Earthquake Resistance”

1. INNOVATIVE MATERIALS;2. STRENGTHENING SYSTEMS;3. PROTECTION STRATEGIES;4. CASE STUDIES.

Basic purposes: Use of materials with special properties in order to

meet special design requirements and achieve the best performance;

Creation of light structural elements, in order to optimize the dynamic behaviour;

Exploitation of material features in the most convenient and effective way (exploitation of the 4th dimension);

Creation of special devices for the reduction of the seismic structural response;

INNOVATIVE MATERIALS

Innovative materials Special Metal Materials; Fibre Reinforced Polymers (FRP);

Material: Stainless steel Aluminium alloys Titanium alloys Shape memory alloys

INNOVATIVE METAL MATERIALS

Features: High strength-to-weight ratio Good ductility Product availability Ease of installation Low maintenance cost Reversibility

TITANIUM ALLOYS

SPECIAL METAL MATERIALS

PURE ALUMINIUM SHEAR PANEL

CONFIGURATION TYPE F

-50

-40

-30

-20

-10

0

10

20

30

40

50

-0.1 -0.08 -0.06 -0.04 -0.02 0 0.02 0.04 0.06

shear strain (mm/mm)sh

ear

str

es

s (

MP

a)

meccanismo 'pure shear'meccanismo 'tension field'

meccanismo 'pure shear'meccanismo 'tension field'

ALUMINIUM SHEAR PANELS

ELONGATION -TENSILE LOAD CURVE

0

200

400

600

800

1000

0 10 20 30 40 50 60

ELONGATION (mm)

LO

AD

( D

aN

=kg

)

NOT HEAT-TREATED SPECIMEN

HEAT-TREATED SPECIMEN

Material: Carbon fibre polymers Glass fibre polymers Aramidic fibre polymers

INNOVATIVE FIBRE-REINFORCED MATERIALS

Features: Very high strength and stiffness Wide range of mechanical properties No added weight Product availability Ease of installation No maintenance cost

FIBRE-REINFORCED MATERIALS (Courtesy SIKA)

FIBRE-REINFORCED MATERIALS

APPLICATION OF FIBRE-REINFORCED ELEMENTS

USE OF FIBRE-REINFORCED STRIPS

Strengthening of earthquake damaged structures by means of textile reinforced concrete

J.-U. Sickert, M. Kaliske, W. Graf

Technische Universität Dresden

TRC layer on a hyper parabolic shell

Cylinder shell to be strengthened

WG2 - INNOVATIVE MATERIALS

MRM-element with three reference planes

Results of the analysis

WG2 - INNOVATIVE MATERIALS

Seismic upgrading of RC buildings by advanced techniques.

The ILVA-IDEM research project (2006)

Mazzolani, F.M. (Co-ord. and Ed.)

Seismic Upgrading of RC buildings by FRP: full scale tests of a real structure (2006)

Della Corte, G., Barecchia E., Mazzolani, F.M.

University Federico II Naples – Italy

WG2 - INNOVATIVE MATERIALS

Thin fibre-reinforced concrete jackets for im-proving the seismic response of reinforced concrete members: experimental and numerical results (2008).

Georgiadi-Stefanidi, K., Mistakidis, E., Perdikaris, P.C.

University of Thessaly, Volos, Greece.

WG2 - INNOVATIVE MATERIALS

Strengthening of masonry walls by innovative metal based techniques (2007)

A. Dogariu, A. Stratan, D. Dubina, T. Nagy-Gyorgy, C. Daescu & V. Stoian

Performance of masonry shear walls strengthened with steel and aluminum sheething (2008)

A. Dogariu, D. Dubina

Politehnica University of Timisoara, Romania

Retrofitting techniques

Weak area on masonry façade and location of metal sheeting (MP)

Steel wire mesh (SWM) geometry

WG2 - INNOVATIVE MATERIALS

Seismic upgrading of RC buildings by advanced techniques.

The ILVA-IDEM research project (2006)

Mazzolani, F.M. (Co-ord. and Ed.)

Response of Buckling Restrained Braces to Catastrophic Seismic Events (2008)

D’Aniello M., Della Corte G., Mazzolani F. M.

University Federico II Naples – Italy

WG2 – STRENGTHENING SYSTEMS

Performance based evaluation of a non-seismic RC frame strengtened with buckling restrained braces

S. Bordea, A. Stratan, D. Dubina

Politehnica University of Timisoara, Romania

Types of analysed frames

BRB systremFrame geometry and

characteristic beam and column cross-sections

WG2 – STRENGTHENING SYSTEMS

BRB behaviour model

Effect of confinement by FRP on the moment-curvature

relationship

Plastic hinges with inelastic deformations larger than the ULS capacity; Fundamental period of vibration and target displacements

Removable Bolted Links For Eccentrically Braced Frames

A. Stratan, D. Dubina

Politehnica University of Timisoara, Romania

The bolted link concept

Simplified model of a generalized dual system

WG2 – STRENGTHENING SYSTEMS

Failure modes and force-deformation plots of tested specimens

WG2 – STRENGTHENING SYSTEMS

Experimental tests on seismic upgrading techniques for RC buildings (2007)

F. M. Mazzolani, G. Della Corte, E. Barecchia & M. D’Aniello

University of Naples Federico II, Naples, Italy

Test n. 1

WG2 – STRENGTHENING SYSTEMS

Test n. 2

Test n. 3

WG2 – STRENGTHENING SYSTEMS

Shear panels for seismic upgrading of new and existing structures (2007)

F. M. Mazzolani, G. De Matteis, S. Panico, A. Formisano, G. Brando

University of Chieti/Pescara G. d’Annunzio, Pescara, University Federico II Naples – Italy

b) c)

WG2 – STRENGTHENING SYSTEMS

• Increase of the structural damping, in order to reduce the structural response under seismic action;

• Reduction of the seismic input energy, in order to prevent structural damage;

• Reduction of the inertia forces, in order to reduce the structural response at a given frequency of the dynamic excitation;

BASIC PURPOSES OF SEISMIC CONTROL TECHNIQUES

WG2 – PROTECTION STRATEGIES

Seismic protection of new and existing buildings using an innovative isolation system (2008)

A. Michalopoulos, T. Nikolaidis, C. Baniotopoulos

Aristotle University of Thessaloniki

Motion of a steel sphere between two horizontal steel plates under axial

compression load P

A schematic part of the innovative spherical in-plane steel rolling

bearing

The positioning of the aseismic isolation system Cylindrical aseismic isolation system

WG2 – PROTECTION STRATEGIES

SMART TECHNOLOGIES IN THE SEISMIC PROTECTION OF EXISTING BUILDINGS (2008)

A. Mandara, F. Ramundo, G. Spina

Second University of Naples

Representation of SMART system effect

Scheme of Variable Orifice Damper and Electro-Rheological Damper with by-pass

Scheme of a Magneto-Rheological Damper (a) and details of the MR devices developed at the Second

University of Naples (b,c,d).

WG2 – PROTECTION STRATEGIES

Seismic protection of buildings using innovative isolators based on magnetically

controlled elastomer (2008)

T. Isaković, M. Fischinger

University of Ljubljana, FGG, Slovenia

Prototype and scheme of the new MCE device A model of the Augusta Hospital and properties of the HDRB, used to isolate the structure

Storey spectra (accelerations of the equipment ) of the mock-up for different earthquake intensities

Mass acceleration of the SDOF structure isolated with HDRB with

different degree of nonlinearity and with MCE isolator

Experimental vs simulation results

WG2 – PROTECTION STRATEGIES

Verification of effectivenes of seismic protection

and retrofit techniques by experimental testing (2008)

L.Krstevska, Lj.Taskov

Institute of Earthquake Engineering and Engineering Seismology,

Skopje, fyRepublic of Macedonia

The experimental verification can be performed on site and/or in laboratory conditionsusing the following testing methods:

• full scale testing

• quasi-static testing

• testing of models in reduced scale on shaking table

• material testing (prototype and model materials)

Locananda Pagoda- BurmaFossanova Abbey-Italy Finland Embassy- Alger

President Palace- Baku

WG2 – CASE STUDIES

Phase 1 - Damage to the minaret (horizontal crack) and

of the mosque.

Phase 2 - Repaired model and strengthened minaret after phase 1.

Phase 3 - Damage of the strengthened model

MUSTAFA PASHA MOSQUE – SKOPJE

(FP6 – PROHITECH)

The FE model of the Mosque

Distribution of first principal plastic strains on the original model at collapse load.

Distribution of first principal plastic strains on the reinforced model at collapse load.

Comparison between experimental and numerical response for the original and

strengthened Minaret model.

Comparison between experimental response for the original and strengthened Minaret model.

pianta piano terra Quota (+1.02)

PROSPETTO NORD

scala 1 : 350

Retrofit of high-rise masonry buildings

A. Mandara et al.

Second University of Naples

CATHEDRAL BELL TOWER – AVERSA

VIBRATION MODES

isolation plane

Smart device

-25

-20

-15

-10

-5

0

5

10

15

20

25

0 10 20 30 40 50 60 70 80 90

Dis

pla

ce

me

nt

[cm

]

No control

Passive

Semi-Active Clipped opt Proposal of application

of Smart Systems

WG2 – CASE STUDIES

ACTIVE STRUCTURAL CONTROL – COMPARATIVE NUMERICAL ANALYSIS

El CentroCalitriKobeTaiwan earthquake

Unconnected mass

Connected mass

Passive control

Semi-active control

Active control

Fg1(t)

K1

C1

M1

s1(t)

s2(t)

U

M2

C2

K2 Fg2(t)

WG2 – CASE STUDIES

The ILVA-IDEM Project - Full scale test on R.C. Building

F.M. Mazzolani et al.

University of Naples Federico II WG2 – CASE STUDIES

-2000

-1500

-1000

-500

0

500

1000

1500

2000

2500

3000

-0.031 -0.021 -0.011 -0.001 0.009 0.019 0.029 0.039 0.049

Drift angle (rad)

Ba

se S

he

ar

(kN

)

Average 1st floor

The ILVA-IDEM Project - Full scale test on R.C. Building

F.M. Mazzolani et al.

University of Naples Federico IIWG2 – CASE STUDIES

CONCLUSIVE REMARKS

Materials and technologies available today represent an effective tool against any potential risk related to catastrophic seismic events;

The outlined solutions can be effectively tailored to the design of both new buildings and retrofit operations;

Innovative solutions in principle allow to provide the structure with a given predetermined safety level corresponding to any design requirement;

A new design approach based on structural robustness should be set out based on the use of advanced seismic protection techniques;

The standard PB Design procedure should be enhanced in order to account for robustness levels.