SEISMIC BASE ISOLATION IN RETROFIT APPROACH OF AN HISTORICAL MASONRY BUILDING

«PALAZZO GAGLIARDI SARDI»

INTERNATIONAL SEISMIC ISOLATION WORKSHOP ANKARA 13.10.2016

LOCATION

LOCATION: L’AQUILA

INTRODUCTION

INTERVENTIONINTERVENTIONINTERVENTIONINTERVENTION::::The presentation introducesthe structural andconservative interventionperformed on the noble Palace«Gagliardi-Sardi» heavilydamaged from the earthquakewhich hit the city during April2009.

The intervention wasperformed by SACAIM andTENSA both Companiesbelonging to Gruppo de Eccherspecialized the first inconservative restoration andthe second in the Design,production and testing ofSeismic Isolators.

BUILDING CHARACTERISTICS:BUILDING CHARACTERISTICS:BUILDING CHARACTERISTICS:BUILDING CHARACTERISTICS:

Total height: Approx. 15 mTotal lenght 58 metersTotal width 18 meters

CHALLENGE

CHALLENGE:CHALLENGE:CHALLENGE:CHALLENGE:The real challenge was to conserve the «Historical and artistic» value of the building upgrading it in compliancewith the compulsory European and Italian norm (EN15129 seismic devices – D.M.14.01.2008). The difficulty of thepresent intervention lays from a constructive point of view in the need of an intervention at two levels (1)foundation and (2) elevation. The building functionality after the earthquake was compromised due to the manycollapse mechanism between whom we mention partial collapses, injuries, facades overturning, displacement ofthe roof and disruption of the vaults of the main stairs, collapse of the partitions and countertops and damagesto roof slab.

CHALLENGE

Internal vaults collapsing (left) and render ofthe facade overturning in direction of SanFlaviano square (above)

POSSIBLE SOLUTION

POSSIBLE SOLUTION:POSSIBLE SOLUTION:POSSIBLE SOLUTION:POSSIBLE SOLUTION:

StrenghteningStrenghteningStrenghteningStrenghtening thethethethe structurestructurestructurestructure //// IncreasingIncreasingIncreasingIncreasingitsitsitsits resistingresistingresistingresisting capacitycapacitycapacitycapacity????

The first approach foresee a traditional intervention bythe use of jacketing approach with wire mesh toincrease the shear resistance during quake.

The mentioned classic intervention inplies a big impacton the elevation which is not possible without affectingthe hystorical value of the building for the presence ofdecorative elements, valuable roofs and floors, innerfixtures, vaults.

SeismicSeismicSeismicSeismic base base base base IsolationIsolationIsolationIsolation in retrofit?in retrofit?in retrofit?in retrofit?

Due to the above mentioned it was decided to reversethe approach from the one aimed in increasing the«resisting building capacitycapacitycapacitycapacity» to the one of decreasing its«demanddemanddemanddemand»By isolating it from the ground an important decrease ofthe base acceleration is achieved and thus thereinforcing at elevation level are minimal being the mainworks performed at «foundation level».

This was decide after verifying the lack or archeologicalfinds.

ISOLATOR LAYOUT

SEISMIC ISOLATION LAYOUT AT INTERFACESEISMIC ISOLATION LAYOUT AT INTERFACESEISMIC ISOLATION LAYOUT AT INTERFACESEISMIC ISOLATION LAYOUT AT INTERFACE

TOTAL ISOLATORS No.: 102 pcs. TDRI 440-SM-66 53 pcs (Isolator)TPM 2000/±150/±150 49 pcs (Slider)FLAT JACKS 102 pcs

ISOLATOR LAYOUT

AXONOMETRICAL EXPLOSION OF THE SEISMIC ISOLATION SYSTEMAXONOMETRICAL EXPLOSION OF THE SEISMIC ISOLATION SYSTEMAXONOMETRICAL EXPLOSION OF THE SEISMIC ISOLATION SYSTEMAXONOMETRICAL EXPLOSION OF THE SEISMIC ISOLATION SYSTEM

CREATION OF THE FOUNDATION AND INTRODUCTION OF SEISMIC ISOLATORS

FOUNDATION

FOUNDATION

WORKS AT FOUNDATION LEVELWORKS AT FOUNDATION LEVELWORKS AT FOUNDATION LEVELWORKS AT FOUNDATION LEVEL1) Walls strenghtening2) Removal of existing pavement and adding of external supporting

FOUNDATION

WORKS AT FOUNDATION LEVELWORKS AT FOUNDATION LEVELWORKS AT FOUNDATION LEVELWORKS AT FOUNDATION LEVEL3) Creation of the isolator and sliders location and reinforcing of it (and creation of the longitudinal beam)

4) Concrete casting of the longitudinal beam and subsequent stressing of the dywidag bars

FOUNDATION

WORKS AT FOUNDATION LEVELWORKS AT FOUNDATION LEVELWORKS AT FOUNDATION LEVELWORKS AT FOUNDATION LEVEL5) Excavation and creation of a foundation slab and bearing plinth6) Placing of sliders or isolators, creation of a top levelling, placing of a plate jack for the subsequent injection

ISOLAMENTO SISMICO ALLA BASEHIGH DAMPING RUBBER BEARINGS

TDRI 440 SM 66 TDRI 440 SM 66 TDRI 440 SM 66 TDRI 440 SM 66 Tens Damping Rubber Isolators

HIGH DAMPING RUBBER ISOLATORS - TDRI EN15129

The TDRI devices are constituted by layers of elastomer alternating with

steel plates. The reinforcing steel plates are completely embedded in the

elastomer to ensure total protection from corrosion. The isolators are able

to transmit the vertical loads with a very high stiffness and to resist

horizontal seismic forces or not (wind, temperature changes, shrinkage,

creep etc.) with a very low stiffness.

DESIGN PARAMETERSDESIGN PARAMETERSDESIGN PARAMETERSDESIGN PARAMETERS---- G modulus calculated at 100% shear strain- Effective stiffness at dbd displacement- Damping calculated at 100% shear strain

ISOLAMENTO SISMICO ALLA BASEHIGH DAMPING RUBBER BEARINGS

TDRI TDRI TDRI TDRI ---- Tens Damping Rubber Isolators

HIGH DAMPING RUBBER ISOLATORS - TDRI EN15129

POSSIBLE TESTING POSSIBLE TESTING POSSIBLE TESTING POSSIBLE TESTING FACILITIES IN EUROPEFACILITIES IN EUROPEFACILITIES IN EUROPEFACILITIES IN EUROPE

TYPE TESTS TYPE TESTS TYPE TESTS TYPE TESTS ---- EN 15129:EN 15129:EN 15129:EN 15129:

These tests are necessary to characterize the devices behavior in full scale. The tests are performed dynamically at third body independent laboratory.

Future designed Isolators using the same criterion of the already characterized shall not be type tested again.

FACTORY FACTORY FACTORY FACTORY PRODUCTION CONTROL TESTS PRODUCTION CONTROL TESTS PRODUCTION CONTROL TESTS PRODUCTION CONTROL TESTS –––– EN 15129:EN 15129:EN 15129:EN 15129:

20% of the anti-seismic devices to be delivered and installed must be tested in factory production control (FPC testing). Follow the details of two official laboratories according with D.M.14.01.2008.

TESTS:

POTENZA – Unibas University of Potenza Vertical dynamic load 10000 kNHorizontal dynamic load+-1000 kN

PAVIA – TREES Lab. Eucentre University of PaviaVertical dynamic load 50000 kNHorizontal dynamic load -1400/1800 kN

ISOLAMENTO SISMICO ALLA BASETESTING LABORATORY

CE MARKINGCE MARKINGCE MARKINGCE MARKING

TESTING OF HIGH DAMPING RUBBER ISOLATORS - TDRI EN15129

The «CE» marking of seismic isolators foreseethe characterization of their behavior throughprototype testing to be performed over no. 2samples properly produced in compliance withEN 15129. Type testing were performed at thelaboratory which is part of the «Università deglistudi della Basilicata» (Unibas Potenzawww.unibas.it/sislab), The laboratory is anofficial testing laboratory in compliance withArticle 59 of D.P.R. 380/2001 as foreseen fromD.M. 14.01.2008 (ministry decree). The normforesee that the first produced device per eachlot plus the 20% of the total produced devicesshall be tested in factory production control /acceptance in site. The devices are therefore«CE» marked and accompained by adeclaration of constancy of performance.

ISOLAMENTO SISMICO ALLA BASEFPC TESTING

FACTORY PRODUCTION CONTROL TEST (20% OF PRODUCED DEVICES)

ISOLAMENTO SISMICO ALLA BASESLIDING ISOLATORS

FREE SLIDING ISOLATORS FREE SLIDING ISOLATORS FREE SLIDING ISOLATORS FREE SLIDING ISOLATORS ---- TPM TPM TPM TPM ---- POT BEARINGSPOT BEARINGSPOT BEARINGSPOT BEARINGS

The TPM devices are simple free slidingbearings which are not adding anyappreciable stiffness to the system. Theirtask is to carry the vertical loads duringseismic motions providing a minimalfriction in compliance with EN1337-2. Thesliding material is P.T.F.E. and the minimalaccumulated path requested (wearresistance) is 1000 m (10000 m forbridges). They are used in junction withisolators also to help finding thecoincidence of the centre of mass withstiffness centre

They present an high vertical stiffnesswhich is taken into account in seismicretrofit (Design & installation). They aredesigned in compliance with EN1337-5and CE Marked. Devices are characterizedby the following performances:1) Vertical Max. static ULS load 2000 kN2) Max horizontal SLC displacement

+-150 mm

TP TP TP TP ---- Tens Pot Bearing Isolators

PLATE JACKS

CHARACTERISTICS OF PLATE JACK:CHARACTERISTICS OF PLATE JACK:CHARACTERISTICS OF PLATE JACK:CHARACTERISTICS OF PLATE JACK:

a) Nominal plate jack capacity 1700 kNb) Maximum vertical displacement 25 mmc) Max. working pressure 150 bar

PLATE JACKS

INTRODUCTION OF PLATE JACKSINTRODUCTION OF PLATE JACKSINTRODUCTION OF PLATE JACKSINTRODUCTION OF PLATE JACKS

PLATE JACKS

PLATE JACKS INJECTIONPLATE JACKS INJECTIONPLATE JACKS INJECTIONPLATE JACKS INJECTION

PLATE JACKS

INJECTED PLATE JACKS INJECTED PLATE JACKS INJECTED PLATE JACKS INJECTED PLATE JACKS

COMPLETED SEISMIC ISOLATION SYSTEM

SEISMIC INTERFACE

WHAT ABOUT PERIODICAL INSPECTION AND POSSIBLE FUTURE REPLACEMENT?

INSPECTION

INSPECTION HATCHES

INSPECTION

INTERVENTION AT ELEVATION LEVEL TO RESTORE THE ARTISTIC HERITAGE

ELEVATION

ARCHITECTURAL RESTORATION

Roof after restoration

ARCHITECTURAL RESTORATION

Architectural detailsafter restoration

ARCHITECTURAL RESTORATION

ArchitecturalArchitecturalArchitecturalArchitectural detailsdetailsdetailsdetails afterafterafterafter restorationrestorationrestorationrestoration

ARCHITECTURAL RESTORATION

ArchitecturalArchitecturalArchitecturalArchitectural detailsdetailsdetailsdetails afterafterafterafter restorationrestorationrestorationrestoration

AMATRICE EARTHQUAKE ITALY 24.08.2016 «SITE» TESTING OF THE ISOLATED BUILDING

AMATRICE

Magnitudo registered in Amatrice on 24.08.16 at03.36 local time:

• Mw 6 (Richter scale)

Distance of Gagliardi Sardi palace from epicentre:

• about 42 km

Consequences on Gagliardi Sardi structure:

• a purely translationalmovement of about 2-2,5 cm was produced asper the following tracesleft at kerb level

AMATRICE

The Designers Riccardo Vetturini and Giacomo di Marco immediately after the quake compared the real structurebehavior with the one foreseen by the model basing on the acceleration values registered by a very close stationbelonging to Italian Accelerometrical Net which registered the event at only 300 meters of distance from GagliardiSardi building. They used as an input in the model the average equivalent characteristics of the devices (effectivestiffness and damping) being such data included within the factory production control test report of TENSA issuedby the laboratory of the «Università degli studi della Basilicata». Obviously those data have been increased tokeep in consideration the effects produced on the stiffness and damping by the shear isolator deformationrelated to the registered displacement of 2-2.5 cm.

TECHNICALTECHNICALTECHNICALTECHNICAL CONCLUSIONSCONCLUSIONSCONCLUSIONSCONCLUSIONS::::

The result of the analisys supplied as an output the evidence that the model provided displacement in line withthe one registered at site;

In addition the uniformity of displacement along the whole perimeter shows a perfectly translational buildingmotion as a consequence of a good distribution of the stiffnesses with reference to the projection of the centre ofmass at the seismic interface. NO torsional effects were detected;

The isolation system demonstrated a perfect capability of re centring without showing any residual movement;

No damages were done to the structure by the quake and no damages to the isolation system which is designedand tested to resist to shear deformation of roughly 250%.

OUTCOMEOUTCOMEOUTCOMEOUTCOME

The isolation approach is a very important opportunity for the Designers both on the new and even more on thehistorical artistic heritage. It allows an intervention reducing drastically the seismic stress thus avoid an invasivestructural intervention which would geopardize the historical artistic value of it. The cost for the isolators system,plate jacks and equipment to perform the loading of the devices represent a percentage of roughly 2,8% on thetotal value of the project of Gagliardi Sardi seismic retrofitting and its conservative restoration.

RESUME

BIBLIOGRAFIA

BIBLIOGRAFIA:BIBLIOGRAFIA:BIBLIOGRAFIA:BIBLIOGRAFIA:

RELAZIONE STORICA: PALAZZO GAGLIARDI SARDI – RESTAURO E RISANAMENTO CONSERVATIVO - A1 RELAZIONE STORICA Dicembre 2011 Giuseppe Chiarizia, Riccardo Vetturini, Antonio Posabella, Giacomo di Marco, Gaudenzio Leonardis, Manuela Villacroce.

RELAZIONE STORICA: PALAZZO GAGLIARDI SARDI – RESTAURO E RISANAMENTO CONSERVATIVO – S12 FASI ESECUTIVE INSERIMENTO ISOLATORI, R1 ed R2 PROGETTO STRUTTURALE RELAZIONI ILLUSTRATIVA e DI CALCOLO 21/02/2012 Giuseppe Chiarizia, Riccardo Vetturini, Antonio Posabella, Giacomo di Marco, Gaudenzio Leonardis, Manuela Villacroce.

IL SISMA DI AMATRICE COME “COLLAUDO AL VERO” DEL COMPORTAMENTO STRUTTURALE DI ALCUNI EDIFICI IN MURATURA Agosto 2016 a L’AQUILA, ISOLATI ALLA BASE Giacomo di Marco, Riccardo Vetturini

TENSACCIAI S.r.l. Prove di accettazione su isolatori elastomerici serie TDRI 440-SM-66 eseguite in conformità alla EN15129. Certificato 56/2015 17.07.2015 Emesso da Università degli studi della Basilicata.

THANK YOU FOR YOUR ATTENTION!!

Author: Paolo Scotti

Thanks to Eng. Riccardo Vetturini

Product & Commercial Area Manager / Business Developer

p.scotti@tensainternational.com