SERIES Concluding Workshop - Joint with US-NEES ......Leite J, Lourenço PB, Vintzileou E, Palieraki V, Correia AA, Candeias P, Campos Costa A, Coelho E 37 Seismic behaviour of L-

Abstracts

SERIES Concluding Workshop -

Joint with US-NEES

“Earthquake Engineering Research

Infrastructures”

JRC-Ispra, May 28-30, 2013

In memory of Prof. Roy Severn

SERIES Concluding WS – Joint with US-NEES: Abstracts

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Contents

Session 1: Hybrid Testing

Towards faster computations and accurate execution of real-time hybrid simulationMosalam KM, Günay S 2

Robust integrated actuator control strategy for real time hybrid simulationOu G, Dyke SJ, Wu B 3

Real-time earthquake simulation using force controlled actuatorsNakata N, Krug E 4

Assessment of the seismic behaviour of a retrofitted old RC highway bridge through PsD testingBursi OS, Ceravolo R, Di Sarno L, Erdik M, Paolacci F, Sartori M, Pegon P 5

Pseudo-dynamic testing with non-linear substructuring of a reinforced concrete bridge based on systemidentification and model updating techniquesAbbiati G, Bursi OS, Cazzador E, Mei Z, Paolacci F, Pegon P 6Numerical tools for the reduction of complex dynamic modelsAbbiati G, Bursi OS, Cazzador E, Mei Z 7

Geographically distributed continuous hybrid simulation tests using shaking tablesObón Santacana F, Dorka UE 8Pseudo-dynamic testing of a piping system based on model reduction techniquesReza MS, Abbiati G, Bonelli A, Bursi OS 9Monolithic time-integration algorithms for Hamiltonian systems suitable for real-time hybrid simulationsAbbiati G, Bonelli A, Bursi OS, Reza MS 10

Advanced hybrid simulation frameworks for civil structuresPhillips BM, Spencer BF Jr. 11

A support platform for distributed hybrid testingLamata Martinez I, Obón Santacana F, Williams MS, Blakeborough A, Dorka UE 12

Dynamic substructuring for soil structure interaction using a shaking tableTang Z, Dietz M, Li Z, Taylor C 13

Real-time hybrid testing for soil-structure interaction: An adaptive signal processing frameworkDertimanis VK, Mouzakis HP, Psycharis IN 14

Towards an implementation of the FHT technique for SSI systems using nonlinear macroelementsChatzigogos CT, Dietz M, Pecker A, Tang Z 15

Session 2: SERIES Transnational Access to Centrifuge Facilities

Centrifuge modeling of dynamic behavior of box-shaped underground structures in sandÜlgen D, Sağlam S, Özkan MY, Chazelas J-L 17

Investigation of the seismic behaviour of shallow rectangular underground structures in soft soils usingcentrifuge experimentsTsinidis G, Rovithis E, Pitilakis K, Chazelas J-L 18

Investigation of several aspects affecting the seismic behaviour of shallow rectangular underground structuresin soft soilsTsinidis G, Heron C, Madabhushi SPG, Pitilakis K, Stringer M 19

Experimental verification of shallow foundation performance under earthquake-induced liquefactionKaramitros DK, Cilingir U, Bouckovalas GD, Madabhushi SPG, Papadimitriou AG, Haigh SK 20

Centrifuge modelling of the performance of liquefaction mitigation measures for shallow foundationsMarques A, Coelho P, Haigh SK, Madabhushi SPG 21

Centrifuge modeling of pairs of flexible retaining walls in saturated sand under seismic actionsAversa S, De Sanctis L, Maiorano RMS, Tricarico M, Viggiani G, Conti R, Madabhushi SPG, Stringer M, Heron C

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Experimental and numerical investigations of nonlinearity in soils using advanced laboratory-scaled models: Anapplication to the Rome historical centreBozzano F, Bretschneider A, Giacomi AC, Martino S, Scarascia Mugnozza G, Escoffier S, Lenti L, Chazelas J-L,Favraud C, Macé D 23


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Session 3: US-NEES developments

The George E. Brown, Jr., Network for Earthquake Engineering Simulation (NEES): Accelerating improvementsin seismic design and performance by serving as a global collaboratory for discovery and innovationRamirez J 25

Promoting re-use of Earthquake Engineering data through the NEEShubBrowning J 26

Re-use of experimental earthquake data for research: Three illustrative examplesVan de Lindt JW 27

Communicating earthquake engineering:The education, outreach, and training activities of the George E.Brown, Jr. Network for Earthquake Engineering SimulationsFossum B 28

Damping estimation from seismic recordsBernal D 29

Session 4: SERIES Networking Activities: Distributed Database and Qualification of ResearchInfrastructures

A faceted lightweight ontology for earthquake engineering research projects and experimentsHasan MR, Farazi F, Bursi OS, Reza MS 31

The SERIES Distributed Database: Architecture and implementationLamata Martinez I, Ioannidis I, Fidas C, Williams M, Pegon P 32

The SERIES Distributed Database: Exchange format, local DBs and central portal interfaceBosi A, Bousias S, Chazelas J-L, Dietz M, Hasan MR, Madabhusi SPG, Prota A, Blakeborough T, Pegon P 33

Qualification of seismic research testing facilities in EuropeZola M, Taucer F 34

Session 5: SERIES Transnational Access to Shaking Table Facilities on masonry, RC and steelstructures

Full scale testing of modern unreinforced thermal insulation clay block masonry housesLu S, Jäger A, Mendes L, Candeias P, Campos Costa A, Coelho E, Degée H, Mordant C, Sendova V,Rakicevic ZT, Tomazevic M 36

Assessment of innovative solutions for non-load bearing masonry enclosuresLeite J, Lourenço PB, Vintzileou E, Palieraki V, Correia AA, Candeias P, Campos Costa A, Coelho E 37

Seismic behaviour of L- and T-shaped unreinforced masonry shear wallsMordant C, Dietz M, Vasseur L, Degée H 38

Shake table testing of a half scaled RC-URM walls structureTondelli M, Petry S, Lanese I, Beyer K, Peloso S 39

Experimental and numerical investigation of torsionally irregular RC shear wall buildings with RuthermabreakersYakut A, Le Maoult A, Richard B, Ragueneau F, Atanasiu GM, Scheer S, Diler S 40

Assessment of the seismic response of concentrically-braced steel framesBroderick BM, Hunt A, Mongabure P, LeMaoult A, Goggins JM, Salawdeh S, O’Reilly G, Beg D, Moze P, Sinur F,Elghazouli AY, Plumier A 41

Session 6: SERIES Transnational Access to Shaking Table Facilities on wood structures / General onExperimental facilities

Seismic performance of laminated wood frames with moment connections under seismic loads:ExperimentalinvestigationKasal B, Heiduschke A, Pospisil S, Urushadze S, Zembaty Z 43

Investigation of seismic performance of multi-storey timber buildingsPiazza M, Tomasi R, Campos Costa A, Candeias P 44

Experimental study on seismic performances of precast concrete shear wall with joint connecting beamLu X, Wang D, Zhao B 45


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Full-scale pseudodynamic testing of the SAFECAST three-storey precast concrete buildingBournas D, Negro P, Molina F-J 46

Experimental earthquake engineering research in LNEC: Contribution to global seismic performanceassessment of structuresCoelho E, Campos Costa A, Candeias P, Mendes L, Correia A 47

Session 7: Analytical and Experimental work on soil structure interaction, wave propagation andfield testing, including SERIES Transnational Access to Shaking Table Facilities

Caisson foundations subjected to seismic faulting: Reduced-scale physical modellingAnastasopoulos I, Zarzouras O, Georgarakos T, Drossos V, Gazetas G 49

Effect of soil structure interaction on higher modes participationMirfattah SA, Mirfattah SK 50

Estimation of soil structure interaction effects, considering the frequency content of the motionMirfattah SH, Mirfattah SA 51

Development of new infinite element for numerical simulation of wave propagation in soil mediaSesov V, Edip K, Cvetanovska J 52

Design and construction of laminar container for 1-g shaking table testsSesov V, Cvetanovska J, Edip K, Rakicevic ZT 53

Analysis of the dynamic behavior of squat silos containing grain-like material subjected to shaking table testsFoti D, Ivorra S, Trombetti T, Silvestri S, Gasparini G, Taylor C, Dietz M 54

Study of multi-building interactions and site-city effect through an idealized experimental modelSchwan L, Boutin C, Dietz M, Padron LA, Bard PY, Castellaro S, Ibraim E, Maeso O, Aznárez JJ, Taylor C 55

EuroProteas: A full-scale experimental facility for soil-foundation-structure interaction studiesPitilakis D, Rovithis E, Anastasiadis A, Pitilakis K 56

Session 8: Analytical and Experimental Techniques / SERIES Transnational Access to Reaction WallFacility

In-situ seismic performance tests of a scoured bridgeChang K-C 58

Validation of a visual deformation measurement systemBinbir E, Demir C, Ispir M, Ilki A 59

Development of wireless sensors for shake table and full scale testing and health monitoring of structuresRakicevic ZT, Markovski I, Filipovski D, Micajkov S, Garevski M 60

Recent advances in seismic design of RC tall buildings using ultra-high-strength materials in TaiwanHwang S-J 61

Refined and simplified numerical models of an isolated old highway bridge for PsD testsPaolacci F, Alessandri S, Mohamad A, Corritore D, Derisi R 62

Full-scale experimental validation of dual eccentrically braced frame with removable linksStratan A, Dubina D, Ioan A, Taucer F, Poljansek M 63

ANNEX - Workshop program 64

Session 1 – Hybrid Testing

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Hybrid Testing

Session 1

Tuesday, 28 May 2013


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TOWARDS FASTER COMPUTATIONS AND ACCURATE EXECUTION OFREAL-TIME HYBRID SIMULATION

Khalid M. Mosalam and Selim Günay

University of California, Berkeley, USA

This paper reports three recent developments aimed towards faster computations andmore accurate execution of real-time hybrid simulations (RTHS). These developmentswere conducted at the University of California, Berkeley as part of nees@berkeley sitedevelopment for an NSF-funded early–concept grant for exploratory research (EAGER)project, namely “Next Generation Hybrid Simulation – Evaluation and Theory”.

The first of these developments is a standalone RTHS system which can accommodateintegration time steps as small as 1 milisecond. This fast execution time of an integrationtime step is realized by a combination of the computation power introduced by a digitalsignal processor (DSP) card, the physical data transfer between the computationalplatform and the controller and the real-time compatible PID control technology of thecontroller and the servo-hydraulic system. The fast execution feature eliminates errorsthat would be introduced by the application of a predictor-corrector smoothingtechnique. Applications of the developed RTHS system in testing porcelain and polymercomposite insulator posts for high voltage electrical switches are presented anddiscussed.

The second development is the use of an efficient equation solver in RTHS whichdecreases computation time. This efficient solver, which decreases the computation timeby factorizing the Jacobian of the system of linear algebraic equations only once in thebeginning of the simulation, is especially beneficial in RTHS which involves analyticalsubstructures with large number of degrees of freedom. Applications of this developmentfor multi-story multi-bay framed structures with both linear and nonlinear constitutiverelationships are presented.

The third development is a novel use of a three-variable control (TVC) for RTHS on ashaking table configuration. Although the TVC, which employs velocity and accelerationcontrol in addition to the usual displacement control, is nowadays used in conventionalshaking table tests, this development is one of the very first applications of TVC in RTHS.It is demonstrated that the TVC enhances the acceleration tracking in high frequencies,while still eliminating the time delay between the command and feedback displacementsignals. Accordingly, adopting the TVC enhances the performance and reduces the errorsin RTHS.

mailto:nees@berkeley


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ROBUST INTEGRATED ACTUATOR CONTROL STRATEGYFOR REAL TIME HYBRID SIMULATION

G. Ou1, S. J. Dyke1, B. Wu2

1 Purdue University, USA2 Harbin Institute of Technology, P.R. China

Real time hybrid simulation (RTHS) is able to perform substructure test in real time scaleand includes rate dependent feature in consideration. One major challenge for RTHS isthat it requires accurate and prompt execution of boundary condition that is calculatedfrom numerical substructure. In most cases, traditional PID control induces large timelag between desired command and response which may cause system instability andfurther the failure of the test. Many control strategies for servo hydraulic actuator-structure system have been proposed recently to compensate such time lag and othersystem dynamics. This paper introduces a new integrated control strategy into RTHS.

The new proposed Robust Integrated Actuator Control (RIAC) algorithm integrates threekey control components; first is the loop shaping feedback control based on H-∞optimization, second one is a pure delay feed-forward block for control performanceenhancement and an additional Kalman filter for feedback estimation and noisereduction. The combination of the aforementioned blocks provides flexible performancebased controller design according to different evaluation criterion.

RIAC has been tested for displacement tracking on different actuator setups and provedto work effectively. The efficacy of the proposed strategy is demonstrated through RTHSof a 3DOF steel structure with equipped magnetorheological (MR) damper. Theexperimental components herein is the MR damper attached to a large scale actuatorhas maximum force capacity of 2500KN, the numerical substructure is the rest of thesteel structure.


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REAL-TIME EARTHQUAKE SIMULATIONUSING FORCE CONTROLLED ACTUATORS

Narutoshi Nakata, Erin Krug

Johns Hopkins University, USA

This paper reports experimental real-time earthquake simulations using force controlledhydraulic actuators. The method presented here is often referred to as effective forcetest (EFT) method. An experimental setup consisting of a two-degrees-of freedomstructure and two hydraulic actuators at the Johns Hopkins University is utilized forimplementation, verification and validation of multidegrees-of-freedom EFT. Forcefeedback controller design and experimental results are presented and performance andlimitations of EFT are discussed. The idea of the EFT method is to impose a loading tostructures that is equivalent to a reference ground motion using force-controlledhydraulic actuators.

Experimental results in harmonic simulation tests proved that the centralized decouplingloop shaping force feedback controller was able to independently control forces in thetwo actuators without interaction. Experimental results in earthquake simulation testsshowed that the dynamic forces were accurately controlled to provide tracking whilemaintaining robustness. In summary, this paper experimentally proves that MDOF-EFT isfeasible with a centralized decoupling loop shaping force feedback controller.


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ASSESSMENT OF THE SEISMIC BEHAVIOUR OF A RETROFITTED OLD RCHIGHWAY BRIDGE THROUGH PSD TESTING

O.S. Bursi1 , R. Ceravolo2, L. Di Sarno3, M. Erdik4, F.Paolacci5,M. Sartori6, P. Pegon7

1University of Trento, Italy; 2Politecnico di Torino, Italy3University of Sannio, Italy; 4Koeri, Boğaziçi University, Turkey

5University Roma Tre, Italy; 6Alga Spa, Italy; 7Joint Research Center, Italy

The seismic vulnerability assessment of existing and new lifeline systems, especiallytransportation systems, is becoming of paramount importance in resilient socialcommunities. Transportation systems were built worldwide mainly in the late 60s andearly 70s; they were designed for gravity loads and were often equipped with plain steelbars. As a consequence most bridges are not detailed for seismic loads and hence theirstructural performance is generally inadequate under earthquake ground motions. Theexisting state-of-art in the field of seismic performance of existing bridges is scarce. It istherefore urgent to propose reliable procedures for assessing the seismic vulnerability ofexisting bridge structures. The aim is to provide comprehensive guidelines for theseismic assessment and retrofit of existing bridges.

The “Retro” Transnational Access project funded by the European Commission within theSeries-project aims at studying the seismic behaviour of existing reinforced concrete(RC) bridges and the effectiveness of innovative retrofitting systems. The researchactivity focuses on experimental and numerical investigations of old bridges, designedmainly for gravity loads. To this aim, the seismic vulnerability of an existing Italianviaduct with portal frame piers (Rio Torto Viaduct) is evaluated and an isolation systemis designed using both yielding-based and friction-based bearings. An experimental testcampaign is being performed at ELSA Laboratory of JRC (Ispra, Italy). Two specimens(scale 1:2.5), with two (total height is 6.8 m) and three (total height is 11.2 m)transverse girders, one-bay reinforced concrete frame are being built and tested usingthe pseudo-dynamic test technique with sub-structuring. The modelling of the entireviaduct is considered along with the non-linear behaviour of each pier, due to bending,shear on the transverse beams and strain penetration effect at the column bases. Duringthe test the following configurations are considered: 1) retrofitted viaduct using FrictionBearings, and 2) the “as-built” viaduct imposing a medium damage level. For each phaseof the experimental campaign a proper dynamic identification is performed. Naturalrecords selected on the basis of a specific hazard analysis are used during the tests. Thecomprehensive numerical investigations and the first results of the PsD campaign haveshown the high vulnerability of the sample bridge; a passive protection system is thusdeemed necessary. The isolation systems have been designed and characterized,whereas the isolated configuration of bridge will be tested soon.


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PSEUDO-DYNAMIC TESTING WITH NON-LINEAR SUBSTRUCTURING OF AREINFORCED CONCRETE BRIDGE BASED ON SYSTEM IDENTIFICATION

AND MODEL UPDATING TECHNIQUES

G. Abbiati1, O.S. Bursi 1, E. Cazzador1, Z. Mei 1,2, F. Paolacci3 & P. Pegon4

1University of Trento, Italy; 2Harbin Institute of Technology, China3University of Roma Tre, Italy; 4Joint Research Centre, Italy

The seismic performance assessment and retrofit of a concrete bridge by means of atesting program was conceived within the RETRO research activity funded by the SERIESproject. The old 400m span Rio Torto viaduct, under-designed with respect to theseismic load, is considered as Case Study. The installation of a couple of isolationdevices -one per column- for each pier portal frame interposed between the cap beamand the deck was proposed to achieve the Eurocode 8 seismic-performancerequirements. A software framework devoted to test the effectiveness of the seismicretrofit of the bridge through a set of hybrid simulations is presented. In particular, twoof the twelve piers - Physical Substructures (PSs) - will be loaded through dynamicactuators, whilst the remaining ten piers and the deck as well - Numerical Substructures(NSs) - are numerically modelled and solved. A refined Finite Element (FE) fiber model ofthe bridge is implemented in the well-known OpenSEES software to support the pseudo-dynamic test design. Time history analyses conducted on the reference modelhighlighted appreciable nonlinearities of the pier dynamic responses already under theServiceability Limit State. As a consequence, a NS capable of reproducing this nonlinearbehaviour during hybrid simulations is deemed necessary. Nonetheless, implementationissues relevant to the typical execution time of the NS - few milliseconds or controllertime steps - make complex FE fiber models unsuitable for testing purposes. A rigorousnonlinear dynamic reduction of numerical piers was conceived as an extension of theCraig-Bampton method; thus, the 3-DoFs model resulting from the linear dynamicsubstructuring of each single pier is endowed with a simplified Bouc-Wen spring in serieswith a slip spring. Since moment resisting reinforced concrete piers develop a ductileresponse by activating different yielding mechanisms at different excitation levels, a testprocedure aimed at propagating damage from physical to numerical piers is devised: inorder to match the dynamic response of the reference OpenSEES model, at each run, apriori unknown nonlinear parameters characterising the 3-DoFs reduced piers will betuned by means of a robust time-frequency approach. The constitutive laws of fiber-based beam elements of the reference model will be updated from experimentalmeasurements obtained during the previous test. Lastly, the selected continuous timetesting strategy together with a complex NS forced the adoption of a time integratorwhich allows for subcycling; for this purpose, the parallel partitioned PM algorithm isproposed and its experimental implementation to the Rio Torto case study is presented.


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NUMERICAL TOOLS FOR THE REDUCTION OFCOMPLEX DYNAMIC MODELS

G. Abbiati1, O.S. Bursi1, E. Cazzador1, Z. Mei1,2

1University of Trento, Italy2Harbin Institute of Technology, China

Over the last decade, Real-Time (RT) and Pseudo-Dynamic (PsD) testing with DynamicSubstructuring (DS) have gained significant popularity due to their versatility in testingseveral types of linear and nonlinear structural systems. Nonetheless, despite thecontinuous increase of computing power, implementation issues relevant to the typicalsolution time of the Numerical Substructure (NS) make complex Finite Element (FE)models not suitable for testing purposes. Moreover, time integration algorithmscharacterized by a deterministic convergence time are crucial for real-time machines,whereby hybrid simulation code is executed. As a consequence, optimal NSs capable ofreproducing the behaviour of complex dynamic linear/nonlinear systems must be tailoredto ensure robustness to hybrid simulation. In this perspective, a set of numerical toolsdevoted to the reduction of parts of NS models is presented. With regard to the linearcase, MatLAB implementations of well-known reduction methods such as Guyan, SystemEquivalent Reduction-Expansion Process (SEREP), and Craig-Bampton are provided. Withrespect to the nonlinear case, state space models can finely synthetize complex systems.Nonetheless, the identification of the parameters of such models is a quite non-trivialtask. When the trial and error strategy fails, an optimization-based approach must beadopted. The tool we are proposing herein sets the optimum problem in the time-frequency domain. In particular, the minimization of a certain penalty function forces theShort Time Fourier Transform (STFT) of the response of a simplified state space model tomatch the STFT of the response of the reference model being reduced. The modelreduction of piers belonging to the fiber-based FE model of an old reinforce concreteviaduct is presented as an application example. In particular, in order to simulate thetypical hysteretic behaviour of each single pier, the 3-DoFs linear model obtained fromthe dynamic substructuring is combined with a Bouc-Wen spring in series with a slip-lockelement. The optimal tuning of the resulting state space model is done by means of theproposed tool and comparisons are performed with the reference fiber-based FE model.


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GEOGRAPHICALLY DISTRIBUTED CONTINUOUS HYBRID SIMULATION

Ferran Obón Santacana and Uwe E. Dorka

University of Kassel, Germany

One of the tasks within the FP7 SERIES Project was the creation of a European Platformfor Geographically Distributed Tests. This platform was envisioned to be able to deal withdifferent protocols and algorithms so that its users and facilities were not restricted toone specific protocol. The platform should also prove the possibility of performinggeographically continuous distributed tests since up to now the distributed tests betweentwo different countries that have been performed were stop and go. However, thoughthe use of an efficient sub-structure algorithm, continuous tests can be performed usingstandard network connections.

With that in mind several activities were performed at the University of Kassel thatinvolved not only European partners, like the University of Oxford, but also otherfacilities and networks around the world, namely: the University of California atBerkeley, the Hybrid Simulation Testing Center (HYSTEC) in South Korea and theNational Center for Research on Earthquake Engineering (NCREE) in Taiwan. With eachpartner continuous time-scaled hybrid simulation tests with a non-linear sub-structurewere performed exploring the different available protocols. In addition to suchexperiments, the possibility to carry out continuous sub-structure testing with largenumerical models (with the order of a thousand degrees of freedom) using the LinuxCluster at the University of Kassel was studied proving the extensibility of the platformto large and complex numerical models.


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PSEUDO-DYNAMIC TESTING OF A PIPING SYSTEMBASED ON MODEL REDUCTION TECHNIQUES

Md. S. Reza, Giuseppe Abbiati, Alessio Bonelli, Oreste S. Bursi

University of Trento, Italy

Over the last three decades, Pseudo-Dynamic Testing (PDT) with DynamicSubstructuring (DS) has gained significant popularity due to its applicability in testingseveral types of nonlinear structures/systems. In a PDT with DS, a heterogeneous modelof the emulated system is created by combining a Physical Substructure (PS) with aNumerical Substructure (NS) that describes the remainder of the system. However, untiltoday, a major drawback of this method has been considered its inadequacy to test asystem containing distributed masses. With an intention to overcome this limitation, thispaper presents an extension of the PDT with DS technique by enabling its application tostructures having distributed masses. In this respect, we describe the implementation ofthe PDT with DS on a typical petrochemical piping system. Some challenges faced duringthe implementation are shown and strategies adopted to overcome these problems aredescribed. In greater detail, we show the substructuring technique used and how weminimized relevant errors generated owing to this substructuring. We discuss a numberof model reduction techniques adopted for the reduction of the PS and the earthquakeforces to the coupling nodes. Moreover, a stability analysis of the coupled system isproposed. Finally, experimental results are presented and the reliability of the pseudo-dynamic testing technique is discussed for this application.


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MONOLITHIC TIME-INTEGRATION ALGORITHMS FOR HAMILTONIAN SYSTEMSSUITABLE FOR REAL-TIME HYBRID SIMULATIONS

G. Abbiati, A. Bonelli, O.S. Bursi, Md S. Reza


In recent years, hybrid simulation techniques like Real-Time (RT) and Pseudo-Dynamic(PsD) testing with Dynamic Substructuring (DS) became more and more popular tostudy in depth the performance of structures subject to dynamic loads. With regard torelevant time-stepping methods, they can be broadly classified into monolithic andpartitioned. According to the RTDS philosophy, in the monolithic approach, just theNumerical Substructure (NS) is integrated whilst the remainder part, i.e. the PhysicalSubstructure (PS), is considered as a black box. Since common differential models aimedat simulate nonlinearities in the NS make use of state space formulations based onextended state vectors, e.g. the Bouc-Wen model, time integration algorithms conceivedfor Hamiltonian systems are preferable. In this perspective, we provide the Simulinkimplementations of two time integration algorithms belonging to the monolithic class andtailored to first order systems: i) the linearly implicit Rosenbrock-based L-Stable Real-Time compatible (LSRT) algorithm with two stages; ii) the Modified Generalized- (MG- ) method. For a proper selection of the parameters both the algorithms arecharacterized by second order accuracy and linear stability. In particular, the MG-allows for user controlled algorithmic damping. In order to validate the implementations,RTDS experiments on a full-scale industrial piping system are presented.


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ADVANCED HYBRID SIMULATION FRAMEWORKSFOR CIVIL STRUCTURES

Brian M. Phillips1 and B.F. Spencer, Jr.2

1University of Maryland; 2University of Illinois

Hybrid simulation is a cost effective alternative for the experimental evaluation of civilstructures. It combines experimental testing and numerical simulation with the dynamicbehavior of the structure represented numerically. Through substructuring, the totalstructure can be partitioned into experimental and numerical substructures to representthe complete dynamic behavior of the system. The component of interest, experiencingdamage or other complex nonlinear behavior, can be experimentally represented whilethe more easily modeled components represented numerically. Substructuring alsoallows for multiple platforms to independently represent each component. With multipleindependent platforms, a framework is required to coordinate the reliable exchange ofinformation during the hybrid simulation. This paper will review both traditional hybridsimulation and recent advanced in real-time hybrid simulation (RTHS). UI-SimCor issoftware developed at the Univ. of Illinois NEES facility to coordinate multiple platformsduring traditional hybrid simulation. The hybrid simulation framework incorporating UI-SimCor software as the coordinator is split into three categories: (1) experimentalmodules consisting of servo-hydraulic systems, specimens, sensors, and data acquisitionsystems; (2) computational modules consisting of numerical simulation software, and(3) observer modules to coordinate with outside networks and allow for geographicallydistributed hybrid simulation. The UI-SimCor software and framework has provensuccessful for the hybrid simulation of curved bridges under complex seismic loading,semi-rigid steel frames, and multiple education and outreach programs as well as thegeographically distributed hybrid simulation of a bridge focused on soil-structure-foundation interaction. When the dynamic response of the experimental component isdeemed significant and difficult to represent numerically, the experimental componentmust be tested in real-time. This necessitates the entire hybrid simulation to be run inreal-time (i.e., RTHS). The coordination of hybrid simulation components becomes timesensitive and the computational side of the RTHS must be designed for real-timeperformance. In lieu of a flexible framework such as provided by UI-SimCor, applicationspecific coordination is typically developed with only the necessary components included.Dedicated real-time digital signal processors are used for numerical integration andactuator control. The interface between experimental and numerical components,namely servo-hydraulic system, is also designed for speed. However, these actuatorscontribute most significantly to the time lag in the RTHS loop of action and reaction.Actuator control techniques must be developed to compensate for these actuatordynamics such that they do not influence the results of the RTHS. A framework for RTHShas been developed at the University of Illinois incorporating high-performance hardwareand software. To provide accurate tracking of the desired trajectories, a model-basedactuator control technique is incorporated in the framework. The framework has provensuccessful at testing multi-degree-of-freedom systems with an MR damper as theexperimental component. Furthermore, the technique has been extended to includemulti-actuator systems for the testing of complex experimental components.


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A SUPPORT PLATFORM FOR DISTRIBUTED HYBRID TESTING

Ignacio Lamata Martinez1, Ferran Obon Santacana2, Martin S. Williams1,Anthony Blakeborough1, Uwe E. Dorka2

1University of Oxford, Department of Engineering Science2University of Kassel, Institute of Structural Engineering

Large-scale testing continues to play an important role in earthquake engineering,generating research results that lead to improved safety and security of Europeansociety. Distributed hybrid testing offers a promising approach to use resources fromgeographically separate laboratories in a highly efficient way, to perform more complex,larger-scale tests than are possible in most individual laboratories. The method involvessplitting a structure into a set of substructures (some tested physically, some modellednumerically) located in different laboratories. Simulation of the full structural responseinvolves simultaneous testing of the substructures with feedback of data between them,requiring fast communication through computer networks. To handle systems involvingrate dependence, there is a desire for test speed to approach real time.

Organizing and planning distributed experiments entails much more complexity than isinvolved in a single-laboratory hybrid test, besides the difficulty of tracing errors causedby the distributed environment. This points to the importance of a platform to supportthe testing activities.

This platform has been achieved by means of a specification called Celestina, created atthe University of Oxford. Celestina provides a framework for conducting the experimentworkflow. It provides a specification for the services to be implemented, under threemain headings of networking, test definition and experiment execution, and supports theactual data exchange during a test. It does not force any particular implementation,which can be independently developed and implemented under this framework, and nordoes it restrict the actual method of data exchange.

In this article we discuss the design and conception of the specification as well as oneimplementation that has been validated through a series of substructured “numericalexperiments” in partnership with the University of Kassel. In a typical substructured test,nodes at Oxford and Kassell were used to simulate the response of a 33-DOF steel framefitted with a TMD, with both nodes conducting testing (in simulation) according toinstructions from a Celestina-based program running in Oxford.


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DYNAMIC SUBSTRUCTURING FOR SOIL STRUCTURE INTERACTIONUSING A SHAKING TABLE

Zhenyun Tang1, Matthew Dietz2, Zhenbao Li3, Colin Taylor2

1 Kyoto University, Japan2 University of Bristol, UK

3 University of Technology, Beijing, China

The experimental investigation of soil-structure interaction phenomena is typicallyperformed on a shaking table with a model foundation-structure system embedded in asoil container. As the size and power of the shaking table limits the size of the specimen,only small scale models can be tested using this method. A novel structural testingmethod to overcome this disadvantage is supplied by the real-time dynamicsubstructuring. This paper develops a real-time substructuring testing system for theseismic simulation of soil-structure interaction using a shaking table. The soil-foundationsystem was modelled numerically, the superstructure was modelled physically, and theshaking table was used to reproduce the interface response. A new model-based controlstrategy called Full-State Compensation via Simulation (FSCS) is used to compensate forthe dynamics of shaking table that is a conjunction of Inverse Dynamics Compensationvia Simulation and full-state feedback. The results from an entirely physical test arecompared to those from a real-time dynamic substructuring test in order to verify thevalidity of this method.


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REAL-TIME HYBRID TESTING FOR SOIL-STRUCTURE INTERACTION:AN ADAPTIVE SIGNAL PROCESSING FRAMEWORK

Vasileios K. Dertimanis, Harris P. Mouzakis, Ioannis N. Psycharis

National Technical University of Athens, Greece

This study investigates the problem of conducting real – time hybrid tests for soil –structure interaction using shaking tables. To this, a novel framework was formulated onthe basis of adaptive signal processing and parameter estimation methods. The formerwere utilized in order to compensate the dynamics of the shaking table, while the latterwere used for the compensation of the total transfer delay.

Specifically, an adaptive inverse control scheme was designed and placed between thenumerical substructure and the transfer system, aiming at “canceling” the dynamics ofthe shaking table. It follows that the cascade of the adaptive controller and the shakingtable becomes a delayed unit impulse response. To compensate this delay, a multi –step ahead predictor was estimated by performing parametric and non – parametricidentification on the specimen (physical substructure).

The applied methodology is characterized by two additional innovative features: (1) itreplaces the traditional displacement command to the physical substructure by theacceleration one. This allows a wider response spectrum to be actually implemented tothe specimen; and (2) it replaces the traditional load cell sensor for force feedback by anaccelerometer that is placed on the specimen mass.

The method was applied to a simple, linear SDOF structure (physical model) on ahorizontally deformable soil, reducing, thus, the SSI problem to two – DOF. Twospecimens were tested, with periods of 0.5 s and 0.2 s, both having a specimen – to –foundation mass ratio equal to 4. While the results of this implementation scheme werepromising, the corresponding adaptation process requires further investigation, in orderto avoid effects that alter its performance.


15

TOWARDS AN IMPLEMENTATION OF THE FHT TECHNIQUE FOR SSI SYSTEMSUSING NONLINEAR MACROELEMENTS

Charisis T. Chatzigogos1, Matt Dietz2, Alain Pecker1, Zhenyun Tang2,3

1Géodynamique et Structure, France2University of Bristol, UK3Kyoto University, Japan

Joint Research Activity 3 of SERIES has been concerned with experimental andtheoretical investigations of interacting soil-structure systems under earthquake loading.In one of the subtasks of this activity, the University of Bristol and Géodynamique &Structure (GDS) have collaborated towards an implementation of the first variant of theFast Hybrid Testing technique using nonlinear foundation macroelements as thenumerical substructure.

Efforts towards this goal have been twofold: regarding shaking table control, research atthe Univ. of Bristol has been principally concerned with the development of a novelcontroller for shaking table sub-structuring capable of dealing with issues of shakingtable dynamics such as phase lag and magnitude error within a frequency range ofinterest. The developed novel controller, called Full State Compensation via Simulation(FSCS), has been based on inverse dynamics compensation and full-states feedbackcontrol techniques and has been shown to exhibit enhanced stability and accuracyproperties with respect to conventional compensation controllers. The controller has thusbeen introduced in an integrated single degree-of-freedom shaking table sub-structuringtest system allowing for real-time sub-structuring, particularly adapted for high-frequency, low-damping substructures and high-magnitude excitation frequencies. In aparallel activity, GDS has been focusing on the development of a nonlinear dynamicmacroelement for shallow foundations. The scope has been to propose a formulationencompassing the main sources of nonlinear behavior at the soil-foundation interface (inparticular soil plasticity, foundation uplifting and relative sliding along the interface),which will be general enough to be used for different soil types and shallow foundationgeometries. Introduction of the foundation macroelement can be thought of as a degree-of-freedom condensation procedure, in which the entire foundation and soil domain arereplaced by a link element with three (2D kinematics) or six (3D kinematics) degrees-of-freedom. The interest in using macroelements in FHT is that a quasi-simultaneousresolution of the nonlinear constitutive behavior of the numerical substructure can beachieved, respecting the inherent constraints of real-time sub-structuring testing.

The two developments have been brought together in a realization of the first variant ofthe FHT technique, in which the superstructure is modeled physically on the shakingtable whereas the foundation and soil substructure are modeled numerically. Using thenovel FSCS controller for the shaking table dynamics and introducing the foundationmacroelement as the numerical sub-structure, it has been feasible to test single degree-of-freedom model structures under pure seismic loading and obtain qualitative featuresof non-linear SSI such as wide force-displacement loops at the foundation level andresidual foundation displacements at the end of the excitation.

Session 2 – SERIES TA to Centrifuge Facilities

16

SERIES Transnational Access toCentrifuge Facilities

Session 2



17

CENTRIFUGE MODELING OF DYNAMIC BEHAVIOR OF BOX SHAPEDUNDERGROUND STRUCTURES IN SAND

Deniz Ülgen1, Selman Sağlam2,M. Yener Özkan3, Jean Louis Chazelas4

1Mugla Univrsity (MSKÜ), Turkey2Adnan Menderes University in Aydin (ADU), Turkey

3Middle East Technical University (METU), Turkey4IFSTTAR, Division Reconnaissance et Mécanique des Sols, France

Seismic safety of underground facilities such as pipelines, culverts, subways and tunnelsbecomes an essential requirement for continuing economic and social development.Many engineers earlier thought that the underground structures had been inherentlysafe against earthquakes, but then, especially after the failure of some undergroundfacilities during 1995 Kobe, Japan, 1999 Kocaeli, Turkey and 1999 Chi Chi, Taiwanearthquakes the safety evaluation of the underground structures become a majorconcern of the engineers.

This research aims to investigate the dynamic response of box shaped undergroundstructures buried in dry sand. For this purpose, a series of centrifuge tests are carriedout under harmonic sinusoidal motions by considering the nonlinear behavior of bothstructure and surrounding soil. The dynamic earth pressure is one of the most importantparameters in the seismic design of culverts. However, there is no an establishedmethodology clarifying the mechanism and evaluations of the dynamic earth pressures.Hence, response acceleration in the ground, dynamic strains of the buried models anddynamic soil pressures acting on the buried model are examined with special referenceto the dynamic soil structure interaction. Specific variables considered in this study areinput motion characteristics and rigidities of buried box structures. Three differentmodels are used in the tests with varying rigidities. Results of the experiments areevaluated in order to make an assessment on load transfer mechanism between the soiland buried structure under different motions. Furthermore, the findings of this study arecompared with the predictions of closed-form solutions recommended by Penzien (2000)and Huo et al. (2006).


18

INVESTIGATION OF THE SEISMIC BEHAVIOUR OF SHALLOW RECTANGULARUNDERGROUND STRUCTURES IN SOFT SOILS

USING CENTRIFUGE EXPERIMENTS

Grigorios Tsinidis1, Emmanouil Rovithis2, Kyriazis Pitilakis3, Jean‐Louis Chazelas4

1Aristotle University of Thessaloniki, Greece2Earthquake Planning and Protection Organization, Greece

3 Aristotle University of Thessaloniki, Greece4IFSTTAR, Division Reconnaissance et Mécanique des Sols, France

Seismic response of underground structures is explored by means of well‐documentedexperimental data as part of a Transnational Access action offered by the SERIESresearch project (TA Project: DRESBUS II). For this reason, a series of centrifuge testswere performed at the geotechnical centrifuge facility of IFSTTAR in Nantes focusing onrectangular model tunnels in dry and saturated sands and excited under a centrifugalacceleration of 40g. The testing program aimed at investigating the seismic behaviour ofrectangular tunnels as affected by soil‐structure relative flexibility and soiltunnelinterface characteristics. Both rigid and flexible structures with smooth or roughinterfaces were tested covering a wide range of soil‐tunnel configurations. Numericalanalyses of the observed tunnel behaviour were undertaken by means of the general FEplatform ABAQUS and compared to the experimental data. The effect of salient modelparameters such as the seismic earth pressures and the shear stresses around thetunnel are discussed. The above study is foreseen to shed some light on a set ofimportant but unresolved issues within seismic design of underground structures.


19

INVESTIGATION OF SEVERAL ASPECTS AFFECTING THE SEISMIC BEHAVIOUROF SHALLOW RECTANGULAR UNDERGROUND STRUCTURES IN SOFT SOILS

Tsinidis, G.1, Heron, C.2, Madabhushi S.P.G.1, Pitilakis, K.1 & Stringer, M.1

1Aristotle University of Thessaloniki, Greece2University of Cambridge, UK

Extended underground structures (i.e. tunnels, subways, underground parking lots etc.)constitute significant components of the transportation networks and the builtenvironment. During past earthquakes several cases of extensive damage and evencollapse have been reported for these types of structures, with that of the Daikai subwaystation in Kobe that collapsed during the major 1995 Hyogoken‐Nambu earthquake,being the most interesting. The specific features of underground structures make theirseismic behavior very distinct from aboveground structures. There is a lack of knowledgeregarding several crucial issues affecting this behavior (i.e. dynamic earth pressures onthe side‐walls of a totally embedded structure, seismic shear stresses around thestructure’s perimeter etc.), thus making seismic design very tricky. Actually, for theevaluation of the seismic response of underground structures, several methods may befound in the literature, based on different levels of complexity. The results of thesemethods may substantially deviate, even under the same assumptions, indicating thelack of knowledge regarding the phenomenon. To this end, a set of three dynamiccentrifuge tests have been performed at the University of Cambridge (UCAM) jointly withAristotle University of Thessaloniki (AUTH) on square tunnel models embedded in drysand. The tests were carried out at the geotechnical centrifuge facility of UCAM, withinthe Transnational Access Activities of SERIES (TA project: TUNNELSEIS). Twotunnel‐models were studied; a “rigid” and a “flexible” one, the latter deformed duringswing up and collapsed during an earthquake. The produced experimental data is usedto better understand the seismic behavior of non‐circular embedded structures. The dataobtained will be also used to validate advance numerical models and to improve thedesign methods. The test set ups and the experimental procedure are briefly presentedalong with representative experimental data. Among the main results we observed:

An important effect of the acceleration wave field on the tunnel response. Presence of complex deformation modes for the rigid tunnel (rocking vibration),

usually precluded in the simplified design methods (pure racking deformationassumption).

Residual values for the earth pressures on the sidewalls of the tunnels, caused bythe soil plastic deformations and the soil densification.

Residual values for the internal forces (both in terms of axial forces and bendingmoments), caused by the soil plastic deformations, the soil densification and, tosome extent, due to small amounts of sliding on the soil‐tunnel interface.


20

EXPERIMENTAL VERIFICATION OF SHALLOW FOUNDATION PERFORMANCEUNDER EARTHQUAKE-INDUCED LIQUEFACTION

Karamitros D.K.1, Cilingir U.2, Bouckovalas G.D.1, Madabhushi S.P.G.2,Papadimitriou A.G.3, Haigh S.K.2

1National Technical University of Athens (NTUA), Greece2University of Cambridge (UCAM), UK3University of Thessaly (UTh), Greece

The seismic performance of a square footing, resting on an over-consolidated clay crust,overlying a liquefiable sand layer, is examined herein, through the performance of aseries of three centrifuge experiments, conducted at the Schofield Centre of CambridgeUniversity Engineering Department (CUED). The scope of these experiments is to verifythe beneficial effect of the existence of a surficial non-liquefiable layer (over-consolidatedclay crust) on the response of the footing. In addition, these experiments aim atexploring whether this non-liquefiable layer allows for a viable performance-based designmethodology for shallow foundations, without the need of implementing any soiltreatment on the underlying liquefiable sand. For this purpose, different thicknesses H ofthe clay crust were parametrically used, varying from H=0.65 to 1.50B, with B being thefooting’s width (equal to 3m in prototype scale).

Each test was performed in three stages:

a) The centrifugal acceleration was raised to 50g, in steps of 10g, allowing adequatetime for the consolidation of the clay layer.b) Twenty (20) uniform cycles of harmonic excitation, with a peak acceleration ofamax=0.25g were applied at the base of the equivalent-shear-beam container. During thisstage, excess pore pressures were developed in the sand layer, resulting in theaccumulation of seismic settlements of the footing.c) Immediately after the end of shaking and before the dissipation of excess porepressures, a hydraulic piston was used to increase foundation contact pressure, untilbearing capacity failure, in order to measure the (degraded) post-shaking bearingcapacity. It should be underlined that there are no published experimental data,regarding the liquefaction-induced degradation of bearing capacity of shallowfoundations and this is first time such a study was attempted anywhere in the world.

Following a presentation of the testing configuration and the mechanical properties ofthe two soil layers (clay crust and sand) in this paper, the experimental results arepresented and critically evaluated. The basic mechanisms of foundation performance areanalyzed, during as well as following shaking, while emphasis is given to the effect ofnon-liquefiable clay layer thickness H on the accumulation of foundation settlements.


21

CENTRIFUGE MODELLING OF THE PERFORMANCE OF LIQUEFACTIONMITIGATION MEASURES FOR SHALLOW FOUNDATIONS

Andreia Marques1, Paulo Coelho1, Stuart Haigh2, Gopal Madabhushi2

1University of Coimbra, Portugal2University of Cambridge, UK

Earthquake-induced liquefaction is a major concern for structures built on saturateddeposits of cohesionless soils in seismically active regions, as it often causes failure ofcritical structures and can lead to severe human and economic losses. Destructiveconsequences of this phenomenon were continue to be witnessed from 1964 Alaskan andNiigata earthquakes to more recent 2011 Tohuku earthquake and 2012 New Zealandearthquakes. During the past decades, intensive efforts have been made to understandthe mechanism of liquefaction and to develop liquefaction resistance measures toenhance the performance of foundations during a given seismic event. Centrifugemodelling has been proving its merits as a research tool to facilitate progress in thisfield.

An on-going investigation at the Schofield Centre of Department of Engineering,University of Cambridge, UK, focuses on the performance of shallow foundationssusceptible to seismic liquefaction, which is a particularly important research topic withlarge practical interest. Three centrifuge modelling experiments were carried out toinvestigate the magnitude of liquefaction effects on shallow foundations, under differentconditions, and to assess the performance of innovative mitigation techniques for thisproblem. This paper will present a detailed analysis of the different results obtainedduring the tests and compare the influence of the bearing pressures imposed on theground by two different footings and the performance of different mitigation techniques.A narrow densified zone under the footing and an hybrid technique using densificationand high-capacity vertical drains will be considered in detail. The excess pore pressuremeasured during and after the seismic event will be presented and discussed to evaluateand compare the results obtained in the different situations considered in the modelling.Also, the accelerations measured at different positions in the liquefiable soil and in thestructures tested will be presented to better understand the effects of using a densifiedzone, combined or not with vertical drains. Finally, the settlements of the footingsobtained in every case under study will be presented and discussed, not only during theseismic event but also in the post-seismic phase, to investigate the importance ofconsolidation settlements caused after soil liquefaction.

Clarification of the issues herein identified is a fundamental requirement to betterunderstand, predict and enhance the behaviour of shallow foundations built onliquefiable ground, which can actively contribute to develop innovative liquefactionresistance measures that offer improved cost-benefit ratios.


22

CENTRIFUGE MODELING OF PAIRS OF FLEXIBLE RETAINING WALLS INSATURATED SAND UNDER SEISMIC ACTIONS

(TA PROJECT: PROPWALL)

Stefano Aversa1, Luca de Sanctis1, Rosa Maria Stefania Maiorano1,Michele Tricarico1, Giulia Viggiani2, Riccardo Conti2, Gopal Madabhushi3, Mark Stringer3,

Charles Heron3

1Università degli Studi di Napoli “Parthenope”, Italy2Università degli Studi di Roma Tor Vergata, Italy

3University of Cambridge, UK

The centrifuge tests carried out under the research project PROPWALL at the SchofieldCenter of the Cambridge University Engineering Department are presented anddiscussed. The tests were carried out on flexible retaining walls embedded in saturatedsand excited by a train of quasi-sinusoidal waves. The piezometric head of the porosityfluid, methyl cellulose, was at dredge level. Two tests were carried out on pairs offlexible retaining walls with one level of support near the top, while the remaining twotests were performed on cantilevered walls. The experimental equipment, the modelpreparation and the monitoring devices are described in detail. The results are presentedin terms of accelerations, deflections, bending moments and excess pore pressures, asmonitored through the devices installed on the walls and within the soil mass. Apreliminary interpretation of the observed behaviour is also given.


23

EXPERIMENTAL AND NUMERICAL INVESTIGATIONS OF NONLINEARITY INSOILS USING ADVANCED LABORATORY-SCALED MODELS:

AN APPLICATION TO THE ROME HISTORICAL CENTRE(TA PROJECT: ENINALS)

F. Bozzano1, A. Bretschneider1, A.C. Giacomi1, S. Martino1, G. Scarascia Mugnozza1, S.Escoffier2, L. Lenti2, J-L. Chazelas2, C. Favraud2, D. Macé2

1 “Sapienza” University of Rome, Italy2 IFSTTAR, France

The SERIES TA project “Experimental and Numerical Investigations of Nonlinearity insoils using Advanced Laboratory-Scaled models” (ENINALS) was focused on thecentrifuge modeling of seismically-induced strains vs. stratigraphic features. These lastones were specifically referred to the presence, thickness and location of clay levelsrepresenting the alluvial deposits of the Tiber River in Rome historical centre, which isexposed to Mw>6 earthquakes from the Central Apennine chain with epicentral distancesshorter than 100 km. Several studies have been focused on the amplification effects ofthe Tiber alluvial deposits in Rome historical centre. Moving from this consolidatedknowledge, the main goal of ENINALS was to investigate possible non-linearity effectsassociated with the worst seismic actions in Rome and, namely, related to thestratigraphic juxtaposition of more deformable clayey-silts, and of stiffer sands or sandy-silts. A laboratory-scaled centrifuge modeling with a dynamic action was associated tothe numerical simulation of non linearity by 1D-3C approaches. 4 samples were tested atreduced scale in the centrifuge, representing two homogeneous soil columns (clayey andsandy column respectively) and two heterogeneous soil columns, including a clay levelbetween two sand beds representing a 5m and a 10m clay layer respectively. Theapplied dynamic input represents the maximum expected seismic action in Rome. It wasreproduced at the shaking device as: i) a natural time history, ii) an equivalentsinusoidal signal and iii) a multifrequential equivalent signal derived by the recentlyproposed LEMA_DES approach. The effects of nonlinearity due to seismic shaking in theconsidered heterogeneous soil columns was also simulated by the 1D-3C finite differencenumerical code SWAP, implemented by IFSTTAR. The strain effects obtained for thehomogeneous and for the heterogeneous soil columns were compared and a ShearStrain Concentration Index (SSCI) was computed to define a differential strain rate.Findings show i) a main role of soil heterogeneity in conditioning the shear strains andtheir distribution along the vertical soil profiles and ii) drive to a quantitative approach toevaluate the reliability of 1D vs. 2D-3D conceptual modeling in complex geologicalsetting, as in the case of alluvial valleys filled by heterogeneous soils.

Session 3 – US-NEES Developments

24

US-NEES Developments

Session 3

Wednesday, 29 May 2013


25

THE GEORGE E. BROWN, JR., NETWORK FOR EARTHQUAKE ENGINEERINGSIMULATION (NEES): ACCELERATING IMPROVEMENTS IN SEISMIC DESIGN

AND PERFORMANCE BY SERVING AS A GLOBAL COLLABORATORYFOR DISCOVERY AND INNOVATION

Julio Ramirez

Purdue University, USA

The George E. Brown, Jr. Network for Earthquake Engineering Simulation (NEES) is anetwork of 14 shared-use laboratories (https://nees.org/sites-mainpage/laboratories)connected by a cyberinfrastructure that fosters collaboration in research and education(https://nees.org/).

In the 9th year of official operations, over 400 multi-year, multi-investigator projectshave gone through NEES, yielding many advances in earthquake engineering and awealth of valuable experimental data. At the core of the NEES cyberinfrastructure is theNEES platform for collaboration, NEEShub, providing convenient access to tens ofthousands of users from over 190 countries to the NEES central data repository (ProjectWarehouse). The NEEShub hosts tools for data visualization, analysis, hybrid simulation,education, and collaboration. In this paper a small sample of the many research,outreach, information technology, and educational accomplishments of NEES aredescribed. These examples illustrate the impact of the efforts of the NEES communitytowards improving the resilience of our society against earthquakes and tsunamis.


26

PROMOTING RE-USE OF EARTHQUAKE ENGINEERING DATATHROUGH THE NEESHUB

JoAnn Browning

University of Kansas, USA

Over the past several decades, the civil engineering profession has amassed vastamounts of quantitative data obtained from numerical and physical simulations ofseismic events. But the bulk of the information lives only in printed media that aredifficult and time consuming to use. And much of the generated data are not available injournals because page limits have forced researchers to leave out everything but themost pertinent facts. Further, the limited data that are available in digital format arecumbersome to use because formats vary from source to source.The result is an inefficient method for studying the behavior of structures and soils, withthese common challenges:

Data pertaining to a common design or evaluation issue have to be compiledthrough time‐consuming searches, requiring researchers to explore the ever-increasing numbers of journals almost one by one;

Researchers may need to request additional data from publication authors; Data plots and tables from publications must be digitized, essentially using

manual processes; and Engineers with similar project needs must endeavor to collect and analyze the

same sets of data.

For the past 10 years, the George E. Brown Jr., Network for Earthquake EngineeringSimulation (NEES) has helped to bring data sets to the larger community. NEES’objective is to assist researchers, practicing engineers, and code and guidelinedevelopers as they work on innovations for minimizing damage caused by earthquakesor tsunamis. NEES operations are managed by the NEES Community andCommunications (NEEScomm) Center, which manages the NEES cyberinfrastructure(hosted on NEEShub) and a nationwide network of 14 laboratories(www.nees.org/sites-mainpage) that are available to researchers from U.S.universities and firms. Research at the NEES facilities is funded by the NSF; by otherfederal, state, and local agencies; by private industry; and under the partnerships thatNEES has cultivated with investigators, research facilities, and agencies in Japan,Taiwan, Canada, and China. To date, almost 400 multi‐year, multi‐investigator projectshave been completed or are in progress at NEES sites. The research data has becomeavailable in a digital medium, but there is still a challenge to promote easy re-use of thedata.

NEES has developed a number of initiatives through the NEEShub to help promote datare-use in its most efficient formats. This presentation focuses on several of theseinitiatives, including: establishment of DOI’s for easy reference and promotion ofdatasets, NEEShub Databases, visualization tools, and new data search mechanisms.

www.nees.org/sites-mainpage


27

RE-USE OF EXPERIMENTAL EARTHQUAKE DATA FOR RESEARCH:THREE ILLUSTRATIVE EXAMPLES

John W. van de Lindt

Colorado State University, USA

One of the key contributions of the George E. Brown Network for Earthquake EngineeringSimulation (NEES) lies in the data archival process, particularly the ability of earthquakeengineering researchers to utilize experimental data for research beyond the originalintent of the experiment. Although this seems straightforward in concept, the ability toutilize experimental data based on only what is archived presents a number ofchallenges. For successful data re-use the following are key: (1) data specific to thepurpose of the new study must be available; (2) the needed accuracy which may not bethe accuracy utilized in the original experiment must be available and be able to beidentified; and (3) the ability to properly cite a journal paper or report from the originalexperiment should be readily identifiable. In this presentation, three illustrativeexamples that re-use data from NEES experiments in 2006, 2007, and 2009, focusing ona wood building shake table test, a steel moment frame shake table collapse test, andreversed cyclic tests on reinforced masonry shear- and transverse-walls, are applied tocurrent or recent research studies. The first examples on a wood and steel buildingutilize the global hysteresis to develop collapse models for aftershock studies, while thelatter example calibrates a system level masonry model for use in seismic fragilitydevelopment. In the wood example, the data from a two-story light-frame wood buildingtested at NEES@UB in 2006 was utilized to develop a global hysteretic model with one-degree-of-freedom at each story. The collapse model developed was used to assessaftershock risk of a typical light-frame wood building with future integration into aperformance-based seismic design framework. The steel moment frame test data wasused for a similar purpose but to model typical steel frame buildings. The reinforcemasonry wall data was used to calibrate both shear wall and transverse wall hystereticmodels to implement them into SAPWood, a software package developed within anearlier NEES project. Finally, both challenges and successes of using data from thesethree experimental programs will be presented.

mailto:NEES@UB


28

COMMUNICATING EARTHQUAKE ENGINEERING: THE EDUCATION, OUTREACH,AND TRAINING ACTIVITIES OF THE GEORGE E. BROWN, JR. NETWORK FOR

EARTHQUAKE ENGINEERING SIMULATIONS

Barbara Fossum

Purdue University, USA

The goal of broadening participation of underrepresented groups in engineering has longbeen a priority at the National Science Foundation, and is repeatedly referenced in majorpolicy documents. Underrepresented groups in engineering are currently defined aswomen, Hispanics, African Americans, Pacific Islanders and Native Americans. The NEESnetwork is committed to increasing the diversity of the network across all areas.Additionally the network is inspiring and preparing the next generation of earthquakeengineers through programs involving Research Experience for Undergraduates. Incollaboration with the National Science Foundation (NSF), the Research Experience forUndergraduates (REU) program is a six-week, hands-on, paid research experience forundergraduate students. During this period, students perform research with NEESscientists, participate in education workshops, attend scientific lectures, and develop newskills and interests in earthquake engineering.

This talk will provide an overview of some of the programs implemented at NEES foreducating the next generation of earthquake engineers and increasing awareness of theNEES network. Specific examples include opportunities for increasing the participation ofunderrepresented groups, outreach to K-12 education, research opportunities forundergraduate students and transferring research results to the practicing engineeringcommunity. Participation of minority serving institutions will also be discussed.


29

DAMPING ESTIMATION FROM SEISMIC RECORDS

Dionisio Bernal

Northeastern University, USA

Extraction of damping ratios from input-output measurements is a standard problem inidentification and exact results are obtained by all theoretically consistent algorithmswhen the data generating system is viscously damped, linear, time invariant and theinput-output records are noise free. In practice, however, these assumptions are neverentirely satisfied and, as a consequence, identified damping ratios are random variables.In the particular case of seismic analysis it is well known that identified damping valueshave relatively high variance and it is shown here that this is a consequence of the lowFisher information contained in the response; a significant contributor being therelatively short durations of seismic signals. Notwithstanding the difficulties, values fordamping are needed to formulate predictive models and expressions to estimate theexpected value for buildings have been proposed through the years. Although notexplicitly stated in most cases, these expressions are based on analyses that reflectdissipation within the structure, as well as energy loss through the soil structureinterface. This paper summarizes recent work on characterizing the uncertainty in theestimation of damping, discusses the issue associated with isolating structuralcharacteristics from those of the structure-soil system, and presents some new statisticalexpressions for expected value of the first mode damping ratio derived from analysis of alarge collection of seismic responses.

Session 4 – SERIES Networking Activities: DDB & Qualification of RI

30

SERIES Networking Activities:Distributed Database and Qualification of Research

Infrastructures

Session 4



31

A FACETED LIGHTWEIGHT ONTOLOGY FOR EARTHQUAKE ENGINEERINGRESEARCH PROJECTS AND EXPERIMENTS

Md. Rashedul Hasan, Feroz Farazi, Oreste S. Bursi, Md. Shahin Reza


With the invention of the Semantic Web, computing paradigm is experiencing a shiftfrom databases to Knowledge Bases (KB), in which ontologies play a major role inenabling reasoning power that can make implicit facts explicit to produce better resultsfor users. In addition, KB‐based systems provide mechanism to manage information andsemantics thereof that can make systems semantically interoperable and as such canexchange and share data between them. To overcome the interoperability issues and toexploit the benefits offered by the state of the art technologies, we moved to the KBbased system. Essentially, we have developed an earthquake engineering ontology usinga faceted approach with a focus on research project management and experiments.Following the validation of the ontology by a domain expert, it was published in theknowledge representation language RDF and integrated to the generic ontologyWordNet. The experimental data coming from, inter alia, cyclic and pseudo‐dynamictests were also published in RDF. We used Jena, OWLIM and Sesame tools forpublishing, storage and management, respectively. Finally, integrating the tools,ontologies and data, we developed a system to evaluate the effectiveness of theapproach and in fact we found quite convincing and satisfactory results.


32

THE SERIES VIRTUAL DATABASE:ARCHITECTURE AND IMPLEMENTATION

I.L. Martinez1, I. Ioannidis2, C. Fidas2, M. Williams1, P. Pegon3

1University of Oxford, UK2University of Patras, Greece3Joint Research Centre, Italy

The European scientific community is currently highly fragmented, with each laboratoryholding experimental data, stored in some cases in a non-structured way. As aconsequence, the dissemination and use of experimental results outside of thelaboratory where they are produced can be problematic. This leads to wastefulduplication of tests and ultimately limits the impact of earthquake engineering researchon practice, innovation and earthquake risk mitigation. One part of the SERIESNetworking Activities aim at facilitating the exchange of data and data communicationamong research infrastructures in Europe providing access to data by means of a virtualdatabase. The scope was not to build a central database where local databases wouldeither migrate or merge, but instead to provide centralised access to database nodesthat are distributed over a network that are able to dialog with a central portal in auniform manner. To this end, database nodes use Web Services, to cast their data into auniform standard format for uploading and downloading. The paper concentrates on thearchitecture and the implementation of the Virtual Database.


33

THE SERIES VIRTUAL DATABASE: EXCHANGE FORMAT,LOCAL DBS AND CENTRAL PORTAL INTERFACE

A. Bosi1, I. Kotinas2, I.L. Martinez3, S. Bousias2, J.L. Chazelas4, M. Dietz5, M.R. Hasan6,S.P.G. Madabhusi7, A. Prota8, T. Blakeborough3, P. Pegon9

1Vienna Consulting Engineers, Austria; 2University of Patras, Greece3University of Oxford, UK; 4IFSTTAR, France; 5University of Bristol, UK

6University of Trento, Italy; 7University of Cambridge, UK8University of Naples, Italy; 9Joint Research Center, Italy

The European scientific community is currently highly fragmented, with each laboratoryholding experimental data, stored in some cases in a non-structured way. As aconsequence, the dissemination and use of experimental results outside of thelaboratory where they are produced can be problematic. This leads to wastefulduplication of tests and ultimately limits the impact of earthquake engineering researchon practice, innovation and earthquake risk mitigation. One part of the SERIESNetworking Activities aim at facilitating the exchange of data and data communicationamong research infrastructures in Europe providing access to data by means of a virtualdatabase.

From the User point of view, the approach is based on a scheme for the data to beexchanged (Exchange Data Format), local databases (one prototype DB is currentlydeployed at various SERIES places), interface and tools allowing populating the local DBsand a Central Portal giving access to the SERIES data. The paper presents and discussesall these aspects.


34

QUALIFICATION OF SEISMIC RESEARCH TESTING FACILITIESIN EUROPE

Maurizio Zola1, Fabio Taucer2

1Consultants of P&P LMC, Italy2JRC, Italy

The qualification of large research seismic testing facilities in Europe was one of the maingoals of the SERIES Project. SERIES’s Networking Activity 2 aimed at creating theconditions leading to the qualification of Structural Testing Laboratories specialising inearthquake engineering and equipped for large scale testing. The activities in NA2 wereaimed to address the assessment criteria for technical competence of the researchlaboratories, based on repeatability and reproducibility of the testing activities.The NA2activity was broken down in four Tasks: i) Evaluation and impact of qualification ofexperimental facilities in Europe; ii) Assessment of testing procedures and standardsrequirements; iii) Criteria for instrumentation and equipment management; iv)Development and implementation of a Common Protocol for qualification.

The emergence of performance based engineering (PBE) approaches in earthquakeengineering offers an opportunity to rethink laboratory test approaches by tailoring thetest program to achieve performance outcomes that are explicitly defined for theparticular test specimen. To implement the Qualification a Draft Common Protocolcovering the Management and Technical General Requirements with a check list for theaudits was produced; moreover Specific Technical Requirements for Shaking TableTesting, Reaction Wall Testing, On-site Testing, Data Acquisition and Processing wereidentified and specified in four technical annexes to the Common Protocol.

Thus the qualification of the research testing facilities may be achieved:• by the certification of the Management System after ISO 9001 for the ResearchEngineering Activities;• by the accreditation of the Laboratory after ISO/IEC 17025 for the MeasurementActivities;• by the accreditation of the Laboratory after ISO/IEC 17025 with flexible scope for theResearch Testing Activities.

As far as the accreditation of the Research Testing Activities after ISO/IEC 17025 withflexible scope the Laboratory (Supplier of tests) should receive a Testing Specificationissued by the Research Engineer (Customer) and the Specific Technical Requirements(Annexes to the Common Protocol) should be applied. This proposal for the qualificationof large research infrastructures was presented to the Laboratory Committee of EA inOslo and to the 1st ERNCIP Conference in Ispra.

Session 5 – SERIES TA to Shaking Table Facilities on masonry, RC and steel structures

35

SERIES Transnational Access to Shaking Table Facilitieson masonry, RC and steel structures

Session 5



36

FULL SCALE TESTING OF MODERN UNREINFORCED THERMALINSULATION CLAY BLOCK MASONRY HOUSES

S. Lu, A. Jäger1, L. Mendes2, P. Candeias2, A. C. Costa2, E. Coelho2, H. Degée3, C.Mordant3, V. Sendova4, Z. Rakicevic4, M. Tomazevic5

1Wienerberger AG, Austria; 2LNEC, Portugal3University of Liege, Belgium

4IZIIS, SS "Cyril and Methodius" University, R. Macedonia5Slovenian National Building and Civil Engineering Institute, Slovenia

In the scope of the SERIES project Transnational Access activities, Laboratório Nacionalde Engenharia Civil (LNEC) has provided access to its 3-D shaking table to theinternational construction company Wienerberger AG and to a group of Europeanexperts, in order to perform full-scale seismic tests on an industrial solution forbuildings, using modern unreinforced thermal insulation clays block masonry.

This solution represents a very common construction method in Europe that still lacksseismic vulnerability assessment, because most results available were carried out oncyclic shear tests, thus the effective three-dimensional dynamic response under seismicevents still requires experimental validation.

Consequently, two full-scale mock-ups adopting different geometries were tested on the3-D shaking table using a series of seismic records with increasing intensity.

This paper presents the most relevant results regarding the structural response of thespecimens, e.g. the dynamic response evolution, the collapse mechanism identified andthe maximum drift values measured. The paper closes with the main conclusionsextracted from this work and with the tasks identified for future work.


37

ASSESSMENT OF INNOVATIVE SOLUTIONS FOR NON-LOAD BEARING MASONRYENCLOSURES

João Leite1, Paulo B Lourenço1, Elizabeth Vintzileou2, VasilikiPalieraki2, António A.Correia3, Paulo Candeias3, Alfredo Campos Costa3, Ema Coelho3

1University of Minho, Portugal2National Technical University of Athens, Greece

3LNEC, Portugal

This paper presents the results of the SERIES TA project “Masonry Enclosures”. Theproject addresses the seismic performance of masonry enclosures in European countrieswith moderate and high seismicity based on the experimental evaluation of the seismicresponse of reinforced concrete (RC) frames with innovative solutions for masonry infillwalls, considering both the in-plane and out-of-plane behaviour of the enclosures. Therecent L’Aquila earthquake of 2009 has underlined that the current masonry infillsolutions are not effective, as illustrated by the considerable in-plane damage and out-of-plane collapses throughout the affected areas. Eurocode 8 addresses this issue byimposing the use of reinforced infill solutions but fails to give design and detailingmethodologies.

With the above in mind, a shake table experimental research programme was devised inorder to investigate the seismic behaviour of reinforced infill walls and how they affectthe global structural response.

The first phase of the research activity involved the seismic testing at the LNEC of a two-storey RC infilled frame building designed to the Eurocodes and built at a 1:1.5 scale.These frames were filled with single leaf clay bricks and reinforced plaster was placed onboth sides of the infill walls and anchored to the RC frame and masonry units. Fromthese tests it was possible to assess the evolution of the seismic behaviour of infills andtheir influence on the RC structure through several acceleration inputs of increasingamplitude, associated to cumulative damage limit states.

The second part of the project comprises the dynamic testing of a closed RC plane framewith external dimensions of 6.50mx3.25m and structural elements with 0.50mx0.30mcross-sectional dimensions. This plane frame will be tested simultaneously for in-planeand out-of-plane dynamic actions, representing the response of a frame panel in atypical RC building at different levels. Both motions should match a given floor responsespectra, of narrow band frequency content.

This unique testing setup was specifically designed for this test and is mainly composedof a stiff steel caisson three-dimensional frame which moves rigidly with the shakingtable. It is fixed to the upper beam in the transversal direction, while a system of rollersallows for an independent motion in the longitudinal direction.


38

SEISMIC BEHAVIOUR OF L- AND T-SHAPED UNREINFORCED MASONRY SHEARWALLS

C. Mordant1, M. Dietz2, L. Vasseur1, H. Degée1

1University of Liège, Belgium2University of Bristol, UK

The contribution describes the results of the second phase of the SERIES project TA5carried out at EQUALS laboratory of University of Bristol. The experimental tests aim atinvestigating (i) the influence of walls perpendicular to the seismic action ("flange-like"behaviour) and (ii) the frame effect in load-bearing masonry structures subjected toearthquake action. Two specimens are tested. The first specimen is made of two T-shaped walls connected by a lintel to build up a frame. The two piers are designed sothat the main axis of the first one is perpendicular to the main axis of the second one.Thus, global torsional effects are expected. The second specimen is a frame with two L-shaped walls as piers. The structural system is globally symmetrical, but the connectionof the "flange" (wall perpendicular to the plan of the frame) to the "shear wall" (wall inthe plan of the frame) is different for both piers. In the first pier, flange and shear wallare glued, whereas they are built in the second one. Different load cases are considered(gravity load acting on the flange and/or on the shear wall). Results of the experimentaltests evidence the contribution of the link between piers and highlight a significantrocking behaviour. Depending on its position and on the loading configuration, the flangeis likely to increase the stability of the frame. It is also showed that the torsional effectsand the type of connection largely influence the collapse mechanism. Additionally,identification of natural modes and damping ratios are used to calibrate predictivemodels.


39

SHAKE TABLE TESTING OF A HALF SCALED RC-URM WALLS STRUCTURE

Marco Tondelli1, Sarah Petry1, Igor Lanese2, Katrin Beyer1, Simone Peloso2

1École Polytechnique Fédérale de Lausanne, Switzerland2EUCENTRE, Italy

With the introduction of higher seismic design forces in the Swiss loading standard of2003 most unreinforced masonry (URM) buildings failed to satisfy the seismic designcheck. For this reason, in new construction projects, a number of URM walls arenowadays replaced by reinforced concrete (RC) walls. The lateral bracing system of theresulting structure consists therefore of URM walls and some RC walls which are coupledby RC slabs and masonry spandrels. The same situation characterises a number ofseismically retrofitted URM building across Europe in which RC walls are added to theoriginal structure to improve its behaviour.

Within the framework of the FP7-SERIES project, a four-storey RC-URM wall structureswas tested on the shake table at the EUCENTRE TREES Lab (Laboratory for Training andResearch in Earthquake Engineering and Engineering Seismology) in Pavia (Italy). Thetest was conducted at half-scale and is part of a larger research initiative on mixed RC-URM wall systems initiated at EPFL (École Polytechnique Fédérale de Lausanne). The keyobjective of the testing campaign was to gain insights into the dynamic behaviour ofmixed RC-URM wall structures and to provide input for the definition of a performance-based design approach of such mixed structural system.

Multiple shaking at increasing intensity was used to test the dynamic behaviour of theexamined building. The final shaking induced damage corresponding to the collapseprevention limit state. Furthermore, random noise vibration tests were performed tomonitor the elongation of the natural periods induced by the damage progression.

The paper presents details on the structural system and the selected ground motion, thetest set-up and the instrumentation. Additionally, initial results of the shake table testare presented with a first interpretation of the shown structural behaviour.


40

EXPERIMENTAL AND NUMERICAL INVESTIGATION OF TORSIONALLYIRREGULAR RC SHEAR WALL BUILDINGS WITH RUTHERMA BREAKERS

A. Yakut1, A. Le Maoult2, B. Richard2, F. Ragueneau3, G.M. Atanasiu4,S. Scheer5, S. Diler5

1Middle East Technical University, Turkey2CEA/Saclay, France; 3ENS Cachan, LMT, France

4Technical University of Iasi, Romania5SCHÖCK Company, Germany

Seismic response of reinforced concrete shear wall buildings with irregularities has notbeen studied in detail and thus requires detailed experimental as well as numericalinvestigations. Therefore, a challenging model building having irregularly placed shearwalls in plan has been designed and tested on the AZALEE shaking table at the TAMARISlaboratory in CEA/Saclay. This research project, called ENISTAT, has been granted underSERIES projects via Transnational Access to CEA/Saclay facility in France. The projecthas three main objectives: 1) Study the behaviour of the mock-up under increasing bi-directional horizontal synthetic earthquake records; 2) Attempt to evaluate theexperimental results using modern experimental techniques for data acquisition; 3)Implement & monitor performance of a new structural element that allows for wall-slabconnection to reduce the thermal energy loss. The specimen has been designedprofessionally in conformity with Eurocode 8 and constructed at EMSI Laboratory – CEASaclay. Rutherma elements were used only at the second floor level as a connectionmember between the shear walls and the slab. The model building has beeninstrumented to get measurements of accelerations, displacements and strains atvarious critical locations. To determine relative movement of the second floor slab withrespect to walls due to presence of Rutherma members, relative displacement readingsin the three principal directions were made at five different locations. Prior to testing,numerical analyses have been carried out to determine the test sequence and applicationof ground motion records. Five tests have been performed under a selected syntheticground motion record which is scaled to achieve different PGA levels. The ground motionrecords were obtained artificially such that they conform with the design spectrumdefined in Eurocode 8. After initial low level tests, seismic tests having PGA’s of 0.1g, 0.2g, 0.4g, 0.6g and 0.8g were applied consecutively. Before each tests low level whitenoise tests were performed to determine frequencies of the mock-up. During the firstthree tests, i.e. up to 0.4 g, no significant damage has been observed in the structuralmembers except minor hairline cracks on the spandrel beams. At 0.6g test, more cracksin beams were observed without any major crack in walls. Strain measurements inRutherma steel sections indicated that the strains were within the elastic range. Duringthe 0.8g test, separation of the shear wall member on the flexible side from thefoundation was observed. After the test, major cracks that are mainly confined on thatside in the first floor were observed. No damage on the Rutherma breakers wasobserved.


41

ASSESSMENT OF THE SEISMIC RESPONSE OF CONCENTRICALLY-BRACED STEELFRAMES (TA PROJECT: BRACED)

B.M. Broderick1, A. Hunt1, P. Mongabure2, A. Le Maoult2, J.M. Goggins3, S. Salawdeh3, G.O’Reilly3, D. Beg4, P. Moze4, F. Sinur4, A.Y. Elghazouli5, A. Plumier6

1Trinity College Dublin, Ireland; 2CEA/Saclay, France; 3 NUI Galway, Ireland4University of Ljubljana, Slovenia; 5Imperial College London, UK;

6University of Liege, Belgium

The seismic response of concentrically braced frames (CBFs) is affected by the reducedductility capacity of hollow section bracing members under low cycle fatigue conditions.Seismic response assessment also needs to account for the role of the gusset-plateconnections commonly used in CBFs, which influence local ductility demand in thebracing members. The SERIES TA project BRACED investigates this behaviour in fullscale seismic tests, the results of which are used to validate recently-developed modelsfor the ductility capacity of hollow section bracing members and recent proposals for theimproved detailing of gusset plate connections. The experimental and numerical studiesidentify active yield mechanisms and failure modes in member/connection combinationsand provide essential data on the earthquake response of European CBFs.

The central element of the integrated experimental and numerical research programmeis a series of shake table experiments on full-scale model single-storey CBFs on theAzalee shaking table at CEA Saclay. The model braced frame is 2955 mm high and 4900mm wide and carries a mass of 44 tonnes. The brace member and connection details arevaried between experiments to investigate a range of global and local memberslenderness representative of those found in European buildings. In each experiment,three separate tests are performed with table excitations scaled to produce elasticresponse, brace buckling/yielding and brace fracture. The experimental programmeinvolving 12 independent experiments is supported by correlative pre-test predictionsand post-test simulations using pushover and time-history analysis.

The experimental programme builds on a previous test programme completed under theEcoleader programme at NTUA Athens, but with the test models designed to evaluatethe ultimate earthquake response of CBFs with realistic brace members and connections.In particular, the relative strengths of the brace members and gusset plate connectionsare varied between experiments.

The principal outcomes of the test programme include measurements of thedisplacement ductility capacity of the brace specimens; an evaluation of the influence ofgusset plate detailing on system ductility and frame stiffness; observations on theevolution of response frequency with displacement amplitude; assessment of thecontributions of brace and connection yielding to overall inelastic deformation in CBFs;and measurements of equivalent viscous damping in CBFs.

Session 6 – SERIES TA to Shaking Table Facilities on wood structures / ExperimentalFacilities

42

SERIES Transnational Access to Shaking Table Facilitieson wood structures / General on experimental facilities

Session 6



43

SEISMIC PERFORMANCE OF LAMINATED WOOD FRAMES WITH MOMENTCONNECTIONS UNDER SEISMIC LOADS:EXPERIMENTAL INVESTIGATION

B. Kasal1, A. Heiduschke2, S. Pospisil3, S. Urushadze3, Z. Zembaty4

1TU Braunschweig/Fraunhofer WKI, Germany2 HESS Timber, LLC, Germany3ITAM Prague, Czech Republic

4University Opole, Poland

Laminated wood frames (LWF) offer alternative solutions for mid-rise structures (definedhere as structures of up to about 8 floors high) traditionally built of reinforced concrete(RC) or steel. The laminated wood can be manufactured to relatively large cross sectionsand acceptable load capacities. Previous studies showed that laminated wood frames canresist large seismic loads mainly due to their energy dissipation capacity (Heiduschke,A., B. Kasal, and P. Haller 2009; Kasal, B., I. Pospisil, I. Jirovsky, M. Drdacky,A.Heiduschke, P. Haller 2004). The experiments, described in these papers also showedthat the laminated wood frames will undergo relatively large drifts, which under existingdrift design limitations represents a drawback that needs to be addressed eithertechnically or in the code. While the frames tested and reported in the above literaturehad nonlinear, dowel-bearing type connections capable of moment transfer in onedirection, they required bracing between the bays and light decks were used to supplyadditional torsional stiffness. Such construction is possible but limits the flexibility(bracing must be always present) and presents a design challenges due to the largestiffness differences in two principal directions of the frame. This paper describes theexperimental program that studied the seismic behavior of three-story LWB with spatial(3-dimensional) moment connections. The 3-D moment connections are not common inwood structures due to difficulties in their design and manufacturing. The connectionbetween beams and columns is always facilitated through some kind of steel hardwarethat must be effectively connected with wood. These connections cannot be producedand designed as rigid due to the low dowel-bearing strength of wood and exhibit typicalstress-softening behavior that was studied for decades and large body of literature existsto describe the behavior of joints under cyclic loads. It has been generally accepted thatresults of slow cyclic load (about 0.5-1.0 Hz) can be used in subsequent prediction of atimber joint behavior under more rapidly varying load (such as seismic event) althoughsome load rate dependency of a connection stiffness and capacity has been reported. Inthis work, we have used slow cyclic load to evaluate the properties of 3-D momentconnections and used this information for design and construction of experimentalframes loaded by a seismic forces using shake tables. The methodology, instrumentationand main experimental results of the research programs are presented.


44

INVESTIGATION OF SEISMIC PERFORMANCE OF MULTI-STOREY TIMBERBUILDINGS (TA PROJECT: TIMBER BUILDINGS)

Maurizio Piazza1, Roberto Tomasi1, Alfredo Campos Costa2, Paulo Candeias2

1University of Trento, Italy2LNEC, Portugal

The paper describes the research activities for Transnational Access to EarthquakeEngineering Research Centre (NESDE) at LNEC (Laboratório Nacional de EngenhariaCivil, Lisboa, Portugal), within the framework of the SERIES Project. The aim is to verify,through full-scale shaking table tests, the effects of earthquakes on some timberbuildings characterized by the same geometry (three stories houses, 7 m x 5 m in plan),designed according to the state of the art of the timber engineering, but built throughthree different timber systems: platform frame system (PF), log house system (LH),cross laminated system (CLT). The project involves University of Trento, as Lead User ofTransnational Access Use, University of Minho and University of Graz, and differentindustrial partners. The specimens have been accurately designed taking into account allthe critical point of the different construction systems (connection details, the presenceof openings in walls and in floors, the effect of non-structural elements etc.), and takingadvantages of previous research experiences of each of the team involved in the project.The LH and the two PF structures were tested in May and June 2012, the CLT buildingwas tested on February 2013.

The seismic behaviour of these typologies can be very different, being associated tomany factors such as the plane and elevation regularity, the type and the number ofconnection systems etc. There are aspects so far not sufficiently investigated, such as:

- the deformability of the decks and walls (the relative stiffness significantly influencesthe distribution of horizontal loads on the walls);

- the presence of openings in the panels; Standards, generally, only suggest empiricalfactors in order to reduce resistance, or recommend not to consider as structuralresisting elements the panels containing openings;

- the influence of non-structural elements on the building behaviour.

At European level, there is still a lack of design provisions. Just as an example, the CLTand LH construction systems in Eurocode 5 and Eurocode 8 have not specific designrules, while regarding the structural material (such as the cross laminated panels in CLTsystem), due to the absence of a specific technical Standard for the production, onlyspecific technical approvals must be considered.

The paper illustrates the assumptions, the facts and the present state of this on-goingresearch on earthquake resistant timber houses.


45

EXPERIMENTAL STUDY ON SEISMIC PERFORMANCES OF PRECAST CONCRETESHEAR WALL WITH JOINT CONNECTING BEAM

Xilin Lu1, Dun Wang2, Bin Zhao3

1Tongji University, Shanghai, China

Structural connection is the major feature of precast concrete shear wall distinguishedfrom monolithic shear wall and it plays an important role in seismic performances ofprecast concrete shear wall. Different from widely used technologies such as mechanicsleeve connection and sleeve-mortar splicing connection, joint connecting beam that iscomposed of staggered splicing rectangular steel loops protruding from wall panel,assembly of longitudinal steel bars and stirrups as well as concrete-casting is adopted asan alternative to connect reinforcements of precast concrete shear wall. This paper isconcerned with location and height of the joint connecting beam on performances ofslender precast concrete shear wall with constant axial loading under quasi-static testand comparisons are made with that of monolithic shear wall. The destruction of testspecimen configuration, the top lateral loading-displacement hysteretic curve, shearbearing capacity, deformation, energy dissipation capacity, strength reduction, stiffnessdegradation, reinforcement strain, as well as concrete strain were analyzed. Test resultsshow that shear bearing capacity of precast concrete shear wall with joint connectingbeam is a little smaller than that of monolithic shear wall; the failure mode, stiffness andthe energy dissipation capacity of the precast shear wall specimen are nearly the sameor better than those of the monolithic shear wall specimen. It is indicated that conceptand detailing of the joint connecting beam is feasible and applicable to precast concreteshear wall structure, which has the advantages of with no welding, no costly mechanicsleeves and speeding up construction progress and application of precast concretestructure. In the end, recommendations on the structural design are proposed for furtherapplication of precast concrete shear wall with joint connecting beam.


46

FULL-SCALE PSEUDODYNAMIC TESTING OF THE SAFECASTTHREE-STOREY PRECAST CONCRETE BUILDING

Bournas D.1, Negro P.2, Molina F-J.2

1University of Nottingham, UK2JRC, Italy

In the framework of the SAFECAST Project, a full-scale three-storey precast building wassubjected to a series of pseudodynamic (PsD) tests in the European Laboratory forStructural Assessment (ELSA). The mock-up was constructed in such a way that fourdifferent structural configurations could be investigated experimentally. Therefore, thebehaviour of various parameters like the types of mechanical connections (traditional aswell as innovative) and the presence or absence of shear walls along with the framedstructure were investigated. The first PsD tests were conducted on a dual frame-wallprecast system, where two precast shear wall units were connected to the mock up. Thefirst test structure sustained the maximum earthquake for which it had been designedwith small horizontal deformations. In the second layout, the shear walls weredisconnected from the structure, to test the building in its most typical configuration,namely with hinged beam-column connections by means of dowel bars (shearconnectors). This configuration was quite flexible and suffered large deformations underthe design level earthquake. An innovative connection system, embedded in the precastelements, was then activated to create emulative beam-column connections in the lasttwo structural configurations. In particular, in the third layout the connectors wererestrained only at the top floor, whereas in the fourth layout the connection system wasactivated in all beam-column joints. The PsD test results showed that, when activated atall the floors, the proposed connection system is quite effective as a means ofimplementing dry precast (quasi) emulative moment-resisting frames.


47

EXPERIMENTAL EARTHQUAKE ENGINEERING RESEARCH IN LNECCONTRIBUTION TO GLOBAL SEISMIC PERFORMANCE ASSESSMENT OF

STRUCTURES

E. Coelho, A. Campos Costa, P. Candeias, L. Mendes, A. Correia

Laboratório Nacional de Engenharia Civil (LNEC), Portugal

LNEC has a long experience in all fields of earthquake engineering and has been one ofthe main European institutions developing research & technology activities in severaltopics of this engineering science, such as seismic testing, structural monitoring, hazardanalysis and risk assessment, numerical modelling, development of codes andconsultancy.

In the experimental field, LNEC holds a facility of excellence at European level forearthquake engineering research. Apart from the incorporation of significant materialresources resulting from the dimension of the facility, an interdisciplinary team isresponsible for the assessment of experimental programs, integrating specialists in allfields of earthquake engineering. This allows the use of more appropriate approaches inseismic testing within a comprehensive framework for seismic performance assessment.The experimental facility operates since 1996 and, due to its characteristics, has beenfrom the beginning included in the European group of large-scale facilities in earthquakeengineering, within the “Training and Mobility of Researchers programme” of theEuropean commission (4thFP), later continued through European consortia forearthquake and dynamic experimental research within “Improving Human Potentialprogramme” (5thFP). Presently the LNEC facility holds one of the four largest Europeanshake tables and integrates the strong European 23-consortium SERIES, “Seismicengineering research infrastructures for European Synergies” of the 7th FrameworkProgramme, as one of the European world class research complementary infrastructuresproviding access to external research groups. Therefore, a significant portion of theexperimental work carried out at LNEC results from the fruitful links established withEuropean institutions.

Apart from European collaborations and the 16-year important European funding,several studies with national funding have been developed at the LNEC experimentalfacility for seismic testing, in collaboration with Portuguese research institutions.Additionally several shake table tests have been performed in cooperation with thePortuguese industry, both to study the adequacy of the seismic behaviour of specifictypes of precast reinforced concrete construction systems for use in substations, and toinvestigate the behaviour of electrical and mechanical equipment subjected to dynamicground input motions.

LNEC has also been actively involved in the continued development and implementationof experiments dealing with identification and dynamic characterization of structures, inthe framework of consultancy studies for the seismic assessment of existing structures.While describing the significant legacy of LNEC in the fields of seismic testing and globalseismic performance approaches, particular relevance is given to the participation andmain outcomes of the SERIES’ transnational access, networking and joint researchactivities. Finally, some ambitious plans on future directions for seismic research andtesting at LNEC are outlined.

Session 7 – Analytical & Experimental work on SSI, wave propagation and field testing

48

Analytical and Experimental work on soil structureinteraction, wave propagation and field testing including

SERIES Transnational Access toShaking Table Facilities

Session 7

Thursday, 30 May 2013


49

CAISSON FOUNDATIONS SUBJECTED TO SEISMIC FAULTING:REDUCED-SCALE PHYSICAL MODELLING

I. Anastasopoulos, O. Zarzouras, T. Georgarakos, V. Drossos, and G. Gazetas

National Technical University of Athens, Greece

As part of the SERIES project, the Laboratory of Soil Mechanics of the National TechnicalUniversity of Athens conducted a series of physical model tests to investigate faultrupture propagation through sand and its interaction with embedded caissonfoundations. Besides from being typical for bridge structures, the choice of embeddedcaisson foundations offers the possibility of observing strongly nonlinear phenomena,such as the diversion and bifurcation of the fault rupture path. A series of reduced-scaleexperiments were conducted, investigating: (a) the style of dip-slip faulting (normal orreverse), and (b) the position of the foundation relative to the fault rupture. The“bedrock” is subjected to movement due to fault rupture of vertical offset h at a dipangle α = 45o. The displacements of the foundation, Δx, Δz, and the rotation θ, as wellas the deformation of the soil mass were recorded during the experiments throughimage analysis and laser scanning of the soil surface. In the first case, high-resolutiondigital cameras were utilized to capture images of the deformed soil during the test,which were processed through image analysis software. In the latter case, a noveltechnique was developed and applied through a custom system, designed andconstructed in-house. After each displacement increment, the ground surface wasscanned with 8 laser displacement transducers, travelling along the specimen at aconstant speed, producing a digital relief of the deformed surface. It is shown that thefoundation acts as a kinematic constraint, altering substantially fault rupture path. Thehorizontal and vertical movement and the rotation of the caisson are a function of itsposition relative to the fault rupture. Depending on the latter, a variety of interestinginteraction mechanisms develop, such as bifurcation of the rupture path and diffusion ofplastic deformation. The conducted experiments are in good qualitative agreement withsimilar centrifuge model tests, confirming the validity of the experimental procedure, andenriching the experimental dataset on this important research topic.


50

EFFECT OF SOIL STRUCTURE INTERACTION ON HIGHER MODES PARTICIPATION

Seyed Abolfazl Mirfattah1, Seyed Kazem Mirfattah2

1UME School, IUSS Pavia, Italy2Azad University of Yazd, Iran

Higher modes effects have been usually a concern in designing structures againstearthquake actions since they can alter the internal forces and location of plastic hinges.On the other hand soil structure interaction (SSI) affects the modal properties of thesystem. In this study the effect of SSI on modal participation factor and modalproperties of a simple multi degree of freedom system is investigated. In order tosimulate soil structure interaction a direct method is used and a rigorous finite elementmodel of soil half space is presented. The role of SSI on amplification or attenuation ofhigher modes motions is examined. The results show a dramatic change in theparticipation of higher modes due to soil, foundation and structure interaction.


51

ESTIMATION OF SOIL STRUCTURE INTERACTION EFFECTS, CONSIDERING THEFREQUENCY CONTENT OF THE MOTION

Seyed Hosein Mirfattah, Seyed Ali Mirfattah

JAHAD NASR Consultant Engineering Group, Yazd, Iran

In substructure method used in soil-structure interaction (SSI) analysis, interactionbetween soil and foundation is modeled via spring and dashpot elements. Mechanicalproperties of these elements depend on soil characteristics, foundation properties andalso frequency of motion. Therefore the response of the whole system is also frequencydependant. In this study a number of structures are considered as simplified lumpedmass SDOF systems and equivalent spring and dashpot properties are calculatedaccording to foundation impedance by program DYNA. Circular foundations on soft soil(ground type D) are considered. Then sensitivity of SSI effects on the response, toexcitation frequencies in form of harmonic motions and real ground motions are studied.Results show when the excitation frequency is below a certain threshold, dramaticincrease in maximum drift in short period systems and considerable even in long periodones is observed this threshold is fundamental natural frequency of the whole SSIsystem.


52

DEVELOPMENT OF NEW INFINITE ELEMENT FOR NUMERICAL SIMULATION OFWAVE PROPAGATION IN SOIL MEDIA

Vlatko Sesov, Kemal Edip and Julijana Cvetanovska

IZIIS, University Ss. Cyril and Methodius, R. Macedonia

Numerical simulation of geo-dynamical problems such as propagation of waves in soilmedia still pretends to be huge challenge for geotechnical research community. Modelingof soil geometry as unbounded space have been subject of investigation by manyresearchers [Bettess, 1980; Marques and Owen, 1984; Akiyoshi 1998; Pastor 1999]. Insimulating unbounded domains, infinite elements are very useful tool to describe the farfield behavior, whereas the near field is described through conventional finite elements.The spatial discretization of the far domain is considered using the infinite elements.

This paper presents work that has been done on developing the new infinite elementwhich can be applied on saturated media subjected to dynamic loading. The basic ideaconsists of mapping an infinite region into a finite one. This technique needs appropriatemapping functions by which a domain, unbounded in one direction, is transformed into abounded one. These mapping functions are obtained as a product of standard shapefunctions for finite direction and special mapping functions for the infinite direction. Thesimulation of wave propagation into infinity is realized in the time domain. However, indynamical applications, some additional effects must be taken into account. In fact,when body waves approach the interface between the FE and the IE domains, theypartially reflect back to the near field as the quasi-static infinite elements cannot capturethe dynamic wave pattern in the far field. To overcome this, the waves are absorbed byadding a layer of viscous damping which basically belongs to the absorbing boundariesclass. The idea of adding a layer of viscous damping originates from the work by Lysmerand Kuhlemeyer [1969], in which velocity and parameter dependent damping forces areintroduced to get rid of artificial wave reflections.

Newly infinite element of five nodes has been developed and implemented in ANSYS,using the user programmable features, UPF. An absorbing layer has been added to theinfinite element by considering the wave velocities in the damping matrix. The matricescorresponding to the mapped infinite elements is very similar to the one used for thestandard finite elements. The only adjustment concerns the existence of mappingfunctions different from the shape functions.

Results from performed analytical investigation on one dimensional wave propagationproblems using Heaviside step function and impulse functions and two dimensional wavepropagation in a circular quarter space emphasized some of the key issues regarding thesoil behavior during the wave propagation.


53

DESIGN AND CONSTRUCTION OF LAMINAR CONTAINERFOR 1-G SHAKING TABLE TESTS

Vlatko Sesov, Julijana Cvetanovska, Kemal Edip and Zoran Rakicevic

IZIIS, University Ss. Cyril and Methodius, R. Macedonia

Investigation in the field of earthquake geotechnical engineering involve differentmethodologies and approaches such as dynamic soil element tests, reduced scaledmodels, numerical and analytical models and full scaled field tests. If done properly,scaled model tests can be advantageous for seismic studies due to their ability to givemore realistic information about ground acceleration amplification, variation of porepressures in the soil medium, nonlinear behavior of soil, occurrence of failure, and soilstructure interaction phenomena.

This paper describes the process in design, fabrication and commissioning of a laminarshear box for use in seismic geotechnical studies. A laminar box is a container whichallows ‘friction-free’ horizontal movement of soil model and it is placed on a shakingtable platform to simulate wave propagation during earthquakes through a soil layer offinite thickness. The laminar box described in this paper is built with dimensions 2 x 1 m(plan view) and 1.5 m in height. It is designed to be used for shaking table tests on widerange of geotechnical problems. The numerical analysis and preliminary calculationshave been conducted to study the performance of the laminar box in order to fulfill thedesign criteria are also taken into consideration. Important aspects for the experimentalsetup of liquefaction studies, characterization of investigated sand, model preparation,and soil properties are pointed out. Special type of ‘contact-elements’ are installedbetween laminar rings which significantly improve the free deformability of ground modelsubjected to seismic loading. Amplification, liquefaction and cyclic mobility phenomenon,excess pore water pressure generation and dissipation rates, and further soil-structureinteraction investigations can be performed using such experimental tool. Intensiveshaking table testing at the Geotechnical Laboratory in IZIIS are performing in order toverify the technical characteristics of the laminar box. The construction of such laminarbox is expected to improve the research capabilities of European research area (ERA) inthe field of earthquake geotechnical engineering.


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ANALYSIS OF THE DYNAMIC BEHAVIOR OF SQUAT SILOS CONTAINING GRAIN-LIKE MATERIAL SUBJECTED TO SHAKING TABLE TESTS

Dora Foti1, Salvador Ivorra2, Tomaso Trombetti3, Stefano Silvestri3, Giada Gasparini3,Colin Taylor4, Matt Dietz4

1Technical University of Bari Italy2University of Alicante, Spain3University of Bologna, Italy

4University of Bristol, UK

This paper reports the outcomes of a series of shaking table tests performed at EQUALSlab of Bristol University in the framework of SERIES project. The experimental testcampaign was devoted to the evaluation of the effective behaviour of grain in flat-bottom silos full of grain during an earthquake. This research work starts from all thesame basic assumptions of Eurocode 8 except for the one regarding the horizontal shearforces among consecutive grains. Only this difference leads to a new physically-basedevaluation of the effective mass of the grain, which horizontally pushes on the silo walls.The analyses are developed by simulating the earthquake ground motion with timeconstant vertical and horizontal accelerations and are carried out by means of simpledynamic equilibrium equations that take into consideration the specific mutual actionsdeveloping in the ensiled grain. The findings indicate that, in case of squat silos(characterized by low, but usual, height/diameter slenderness ratios), the portion of thegrain mass that interacts with the silo walls turns out to be noticeably lower than thetotal mass of the grain in the silo and the effective mass adopted by Eurocode 8.

Two series of tests have been performed with two different heights of the ensiledmaterial to simulate a silo more or less squat silo. The ensiled material has beenmodeled with ballotini glass. In the paper, the silo model for the first and second test ispresented, and then the dynamic behavior of the structure is described with reference tothe two series of shaking table tests. The results indicate that, in the case of squat silosthe portion of grain mass that interacts with the silo walls turns out to be noticeablylower than the total mass of the grain in the silo.


55

STUDY OF MULTI-BUILDING INTERACTIONS AND SITE-CITY EFFECT THROUGHAN IDEALIZED EXPERIMENTAL MODEL

Logan Schwan1, Claude Boutin1, Matt Dietz2, Luis A. Padron3, Pierre-Yves Bard4, SilviaCastellaro5, Erdin Ibraim2, Orlando Maeso3, Juan J. Aznárez3, Colin Taylor2

1University of Lyon, France; 2University of Bristol, UK3Universidad de Las Palmas de Gran Canaria, Spain4ISTerre / IFSTTAR, University of Grenoble, France

5University of Bologna, Italy

Seismic risk may be a strong concern for cities as they concentrate population, realestate and/or strategic public services. The common earthquake engineering practicedoes usually consider the substratum, but disregards the resonant ‘surstratum’ made upby the city itself. However numerical and analytical models suggest that global soil-structure interactions, i.e. Site-City effect, can occur and be significant, especially whenthe fundamental frequencies of the soil and of the heaviest buildings coincide.

The aim of the present SERIES-SMISCE study is to investigate experimentally thisphenomenon and to compare the resulting data with two models. In the theoreticalmodel derived by homogenization [Boutin et al. (2006)], the city is shown to act as afrequency-dependent analytical surface impedance. The numerical model consists in a2D, hybrid BEM-FEM approach that describes the layer by boundary elements and thestructures by finite elements. Experimentally, the site-city interaction is studied throughan idealized specimen. A polyurethane foam block with metric dimensions stands for thesoil layer and 37 parallel vertical aluminium sheets stand for the buildings. The buildingscan bend and resonate with out-of-plane excitation, but remain quasi-static with in-planeexcitation. It enables to point out the differences between resonant and inert masses.The specimen is designed to provide a good matching between the fundamentalfrequencies of the foam block and of the aluminium resonators. The whole is attached tothe shaking table of Earthquake and Large Structures Laboratory (EQUALS), and excitedwith a series of signals.

While excited in the non-resonant direction, the system acts classically as a layer withadded inert mass on the top surface. While excited in the resonant direction, globalinteractions (i) split the resonance peak into two peaks that favours beatings; (ii) reducesignificantly both surface and the resonators’ motions at their common fundamentalfrequency; (iii) decrease the amplitude of the resonance peaks; (iv) induce longersignals with slower decreasing codas. Another unconventional phenomenon is adepolarization effect. These specific features have been recovered by both analytical andnumerical models giving (i) a qualitative and quantitative agreement with experimentalresults and (ii) a quasi-perfect agreement with one another.


56

EUROPROTEAS: A FULL-SCALE EXPERIMENTAL FACILITY FORSOIL-FOUNDATION-STRUCTURE INTERACTION STUDIES

Dimitris Pitilakis1, Emmanuil Rovithis2, Anastasios Anastasiadis1,Kyriazis Pitilakis1

1Aristotle University Thessaloniki2Institute of Engineering Seismology & Earthquake Engineering (ITSAK), Greece

We present the experimental campaign to study soil-foundation-structure interaction andwave propagation in soil media due to structural oscillation that took place in theexperimental facility of Euroseistest in Greece. The tests series were performed in theframework of the on-going European project “Seismic Engineering ResearchInfrastructures for European Synergies, SERIES” by means of a real-scale simplifiedmodel structure, called EuroProteas, built in Euroseistest site. A particularly stiffstructure founded on soft soil was designed to mobilize soil-foundation-structureinteraction effects. The structure’s outer dimensions are 3x3x5m having reconfigurablemass and stiffness properties. Two distinct reinforced concrete slabs of 9t mass eachform the superstructure mass, whereas a similar R/C slab is employed as the surfacefoundation of the structure. Superstructure loads are transferred to the foundation soilthough four steel columns, interconnected in all four sides with removable steel bracingsystem. Provisions for mounting an eccentric mass vibrator were made on both thefoundation and the roof slab. Provisions were also made for pull-out experiments by awire rope securely connected to the roof slab. Two boreholes (one at the geometricalcenter of the surface foundation slab and one at 0.5m away from the foundation side)and two trenches in two perpendicular directions allow for dense instrumentation for theresponse recording.

In the framework of SERIES, six experimental campaigns took place: three pull-out(free-vibration) and three forced-vibration sets of tests. Pull-out was performed with a 1tcounterweight and the total pull-out force exceeded 15kN. Forced-vibration tests wereperformed using an eccentric mass vibrator, with sine sweeps in the range between 1Hzand 10Hz, and total force exceeding 20kN. The vibrator was placed both on thefoundation and the top of the structure.

Soil and structural response under free and forced vibration was recorded in a dense 3Darray of more than 60 recording devices (accelerometers, seismometers, shapeacceleration arrays). Instrumentation in the soil covered a volume of 9x9x12m aroundand beneath the foundation. In this paper we present the recorded response fromselected tests, highlighting soil-foundation-structure effects in the structure and in thesoil. We also present some preliminary comparisons between the recorded response andnumerical 2D and 3D simulations of the experiments.

Session 8 – Analytical & Experimental Techniques / SERIES TA to Reaction Wall Facility

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Analytical and Experimental Techniques / SERIESTransnational Access to Reaction Wall Facility

Session 8



58

IN-SITU SEISMIC PERFORMANCE TESTS OF A SCOURED BRIDGE

Kuo-Chun CHANG

National Center for Research on Earthquake Engineering, Taiwan

This paper presents a series of in-situ seismic performance tests of a bridge before itsdemolition due to accumulated souring-induced problem. The tested bridge has twoidentical parallel lanes, while right lane was constructed in 1961 with pier walls, and leftlane in 1995 with circular columns, respectively. Each lane consists of seven 38 m-longsimply-supported PC I-girders. The experiment program includes three cyclical loadingtests and one pseudo-dynamic test. As a strong reaction wall system, the pier wall andtwo supplemental steel A-shape frames were integrated to employ two hydraulic oiljacks, so as to apply lateral force on the column and push column to the targetdisplacements. The column is 180cm in diameter and 1030cm in height, reinforced with30-D32 longitudinal reinforcing bars and transversely reinforced with D16 perimeterhoops spaced 20 cm apart. P3 column represents a benchmark specimen with noscouring, while P4 is exposed up to 33 percent of the length of the caisson foundation.Similar to P3 fixed on the ground, P2 is subjected to a code-compatible groundacceleration of 0.32g first and then followed by a pushover test. Though given twodifferent exposed length of caisson foundation, it is due to gravel material of ground,which is similar to a fixed-base condition, that each column behaved ductile andachieved maximum lateral force of 1000kN at 5% drift ratio with buckling of longitudinalreinforcements and separation of lateral reinforcements. However, the axial load verifiedby the system identification showed a relative small value about 0.05 f'cAg, as a resultto explain why the failure of bridge column was flexural-dominate, even the designdetails didn't satisfied with the current seismic design detail requirements.


59

VALIDATION OF A VISUAL DEFORMATION MEASUREMENT SYSTEM

Binbir E., Demir C., Ispir M., Ilki A.

Istanbul Technical University, Turkey

The pilot studies on visual deformation measurement systems at Structural andEarthquake Engineering Laboratory of Istanbul Technical University (ITU) dates back to2002. At that time visual measurements were made with the support of geomaticsdepartment of Civil Engineering Faculty of ITU.

Usage of conventional measuring devices to obtain deformations has some drawbackssuch as; a) deformations over a small part of test specimen can be measured, b)installation of measuring devices may take notable time, c) during the installation of thedevices, specimens can be damaged due to various attachments, d) for data acquisition,a data logger is generally required, e) the measurement devices may be out of orderduring the test, due to the excessive damage of the specimen, f) due to the nature ofthe applied load and/or the characteristics of specimens, the specimen can fail suddenlycausing damage of the measurement devices.

Considering these drawbacks, a visual deformation measurement system is developed atthe Structural and Earthquake Engineering Laboratory of ITU within Series Project. Thevisual measurement system consists of hardware and software components. Hardwarecomponents include high-resolution camera, lens, metric calibration plate, and I/O card(USB). Software component includes a graphic interface for measurement preparationand related modules and measurement/reporting modules. The capability of the visualsystem is limited from several aspects. The displacements can be tracked in 2D. Thesystem is calibrated for two camera-to-specimen distances (1.5 and 2.5 m) and operateswith a precision less than 0.1 mm.

In order to validate the displacement measurements of the visual system, themeasurements obtained using this system are compared with the measurements of theconventional displacement transducers. The validation study is conducted using thedeformation data obtained from the tests of the short columns confined with FRP sheets.This comparison showed that the visual system measurements are in good agreementwith the conventional measurements.


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DEVELOPMENT OF WIRELESS SENSORS FOR SHAKE TABLE AND FULL SCALETESTING AND HEALTH MONITORING OF STRUCTURES

Zoran T. Rakicevic, Igor Markovski, Dejan Filipovski, Slobodan Micajkov,Mihail Garevski

IZIIS-SS “Cyril and Methodius” University, R. Macedonia

The application of wireless technology to testing and monitoring of civil structures hasbeen gaining considerable interest over the past decade or two.

Wireless sensors are not sensors by themselves, but rather are autonomous dataacquisition nodes to which traditional structural sensors (e.g. accelerometers) can beattached. Wireless sensors are best viewed as a platform in which mobile computing andwireless communication elements converge with the sensing transducer. With wirelesssensors rapidly evolving in multiple engineering disciplines, there currently exist a largenumber of different academic and commercial wireless sensor platforms.

At IZIIS, within the framework of the SERIES project, two types of wireless sensors havebeen developed. The first one MIMRACS (Micro Integrated Measuring, Recording AndCommunication System) sensor presents an intelligent self-controlled high integratedGPS/GPRS/WEB based micro processing digital 3D measurement device, with apossibility for power independence appropriate for measuring, storing and transferringdata with an exact time of their appearance.

given. It has 3 MEMS Model 3028 piezoresistive accelerometers, one for each orthogonalaxis, microprocessor, 24-bit A/D converter, programmable amplifiers, programmabletrigger (x+y+z), inclinometer, gyroscope, GPS/GPRS/GSM modules, Flash memory, USBcommunication and power supply.

The other type is developed on the similar platform as MIMRACS, with a difference that itis more compact and lighter, has one MEMS Model 3028 piezoresistive accelerometerand uses a ZigBee module and protocol for wireless communication.

Both developed sensors are suitable for laboratory testing (shake table testing) and fullscale measurements (ambient and force vibration) of structures, as well as healthmonitoring of structures. The MIMRACS sensor can, also, be used as standalone seismicstation in a network for monitoring and recording of strong motion data.

Both sensors have been tested in laboratory condition by shake table - standalonetesting and testing on models, while recorded signals are compared to traditional wiredaccelerometers. The comparison results showed very good correlation.

In this paper, both developed wireless sensors will be presented in detail, their hardwareand software, as well as comparison results from various conducted tests.

A short review of the world’s wireless sensor development will also be given.


61

RECENT ADVANCES IN SEISMIC DESIGN OF RC TALL BUILDINGS USING ULTRA-HIGH-STRENGTH MATERIALS IN TAIWAN

Shyh-Jiann Hwang

National Taiwan University

Metropolis renewal is an urgent need for Taiwan due to its high population density inurban areas. Constructing the high-rise residential buildings has become a necessity forurban renewal. The use of ultra-high-strength materials for the high-rise RC buildingscan provide a rational solution for this demand. However, the seismic attacks do pose aserious thread for these high-rise RC buildings. Japan had launched the New RC Projectsince 1988. Recently, a 59-story RC building had been successfully constructed in Japan.This clearly indicates that Japan had established a good technology of the high-rise RCbuildings for Taiwan to follow and to start its own. Since 2008, Taiwan started itsresearch programs on the seismic design of RC buildings using ultra-high-strengthmaterials. This speech reviews existing research on RC structures using ultra-high-strength materials in Taiwan to identify findings that may be immediately useful to thestructural engineers in government and private practice who are working on high-rise RCbuilding.


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REFINED AND SIMPLIFIED NUMERICAL MODELS OF AN ISOLATED OLDHIGHWAY BRIDGE FOR PSD TESTS

F.Paolacci1, S.Alessandri1, A. Mohamad1, D. Corritore1, R. Derisi2

1University Roma Tre, Rome, Italy2University of Naples, Naples, Italy

RETRO project aims at studying the seismic behaviour of existing R.C. bridges and theeffectiveness of innovative retrofitting systems. The research program focuses on oldbridges, not properly designed for seismic action. In particular the seismic vulnerabilityof an old-Italian viaduct with portal frame piers will be evaluated. A proper isolationsystem will be designed using Slide Spherical Bearings. On the basis of a previousexperimental campaign consisted of cyclically imposed displacements on 1:4 reducedscale models of a reinforced concrete portal frame pier, belonging to a typical oldhighway viaduct, a new experimental activity has been proposed.

In particular, two specimens (scale 1:2.5), 2-floors and 3-floors one-bay reinforcedconcrete frame respectively, will be realized and tested using the PsD technique withsub-structuring, including the modeling of the entire viaduct. During the test, differentconfigurations will be considered including retrofitted viaduct using Spherical SlidingBearings and “as-built” viaduct.

The aim of the proposed experimental activity is: (i) Increasing the knowledge on thenon-linear behaviour of portal frame piers in presence of plain steel bars on which fewstudies are realized; (ii) Employment of large-scale experimental test for the seismicassessment of existing bridges; (iii) Study of the effectiveness of traditional andinnovative seismic isolation systems (FP isolators).

In this paper the non-linear response of the viaduct in “as-built” and “isolated”configurations are analyzed through a non-linear model developed using the "NLplatform OpenSees". The response of a refined model that takes into account the mainnon-linear phenomena of the viaduct (strain penetration of plain bars, shear deformationof transverse beams, flexural deformations of columns and beams) is analyzed. The aimof the simulations is to evaluate the seismic response of the entire bridges. In additionthe effectiveness of the adopted isolation systems is analyzed and discussed. The resultsare used to simulate the seismic response of the viaduct in the isolated configuration.

The response is carried out using two accelerograms, as in PsD test campaign. Twosignals recorded during the Emilia earthquake in 2012 have been adopted; one for slightdamage condition and the other for Ultimate limit state condition. Because of thecomplexity of the refined model, a simplified model is also proposed. It is composed ofan elastic beam (the deck) connected to non-linear springs, which are calibrated usingthe non-linear cyclic response of each pier. A comparison between refined and simplifiedmodels is shown and some conclusions on the usability of the simplified one are carriedout.


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FULL-SCALE EXPERIMENTAL VALIDATION OF DUAL ECCENTRICALLY BRACEDFRAME WITH REMOVABLE LINKS

(TA PROJECT: DUAREM)

Aurel Stratan1, Dan Dubina1, Adriana Ioan1, Fabio Taucer2, Martin Poljansek2

1“Politehnica” University of Timisoara, Romania2JRC, Italy

Conventional seismic design philosophy is based on dissipative structural response,which implicitly accepts damage of the structure under the design earthquake and leadsto significant economic losses. Repair of the structure is often impeded by thepermanent (residual) drifts of the structure. The repair costs and downtime of astructure hit by an earthquake can be significantly reduced by adopting removabledissipative members and providing the structure with re-centring capability. These twoconcepts were implemented in a dual structure, obtained by combining steeleccentrically braced frames (with removable bolted links) and moment resisting frames.The bolted links provide the energy dissipation capacity and are easily replaceable, whilethe more flexible moment resisting frames provide the necessary re-centring capability.The solution will be validated by full-scale pseudo-dynamic test of a three-storey modelof a steel structure with re-centring capability at the European Laboratory for StructuralAssessment (ELSA) at the Joint Research Centre in Ispra within the framework ofTransnational Access of the SERIES Project financed by the European Commission.

The general set-up of the experimental mock-up, instrumentation, and the test sequenceare described. Pre-test numerical simulations were performed in order to assess theresponse of the structure under different levels of the seismic input, as well as toestablish the optimal sequence of link removal and replacement. Moreover, due toconcerns about the safety of link removal through oxy-fuel cutting as results of suddenrelease of forces, a set of dampers was installed with a temporary bracing system.Numerical simulations were used to provide the optimal damper properties that wouldprevent vibrations in the worst scenario of sudden release of forces during link removal.

Annex – Workshop Program

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ANNEX

Workshop Program


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The workshop

The Joint Research Centre (JRC) hosts a three-dayinternational workshop, within the framework of theEuropean Community’s FP7/2007-2013 Project SERIES(“Seismic Engineering Research Infrastructures forEuropean Synergies”).

The workshop is co-organised with the George E. Brown,Jr. Network for Earthquake Engineering Simulation (NEES,USA) and will present the main outcomes of the SERIESproject and of parallel developments within NEES.

The event is dedicated to the memory of Prof Roy Severn,who established and led the EQUALS laboratory facility atthe University of Bristol and co-ordinated seismicinfrastructure projects which preceded SERIES in past ECFramework Programmes, notably ECOEST I and II andECOLEADER.

SERIES at a glance

European seismic engineering research suffers fromextreme fragmentation of research infrastructures (RI)between countries and limited access to them by the S/Tcommunity of earthquake engineering, especially that ofEurope’s most seismic regions. A 23-strong consortium ofthe key actors in Europe’s seismic engineering research(including 3 industrial beneficiaries) addresses theseproblems in a sustainable way via a 4-year programme ofactivities at an annual cost to the EC which is less than1.35% of the total present value (€190m) of the RIs’material resources.

The project aims at bridging two gaps of RTD inexperimental earthquake engineering and structuraldynamics: (a) between Europe and the US and Japan, and(b) between European countries with high seismicity butless advanced RTD infrastructures on one hand and somemore technologically advanced but not so seismic MemberStates on the other. The entire European RTD communityin earthquake engineering is integrated via:

o A concerted program of Networking Activities,fostering a sustainable culture of co-operation amongall research infrastructures and teams active inEuropean earthquake engineering.

o Co-ordinated Transnational in-person Access of Usersto a world class portfolio combining EU’s largest PsDfacility, four diverse shake tables and two centrifuges.

o Joint innovative Research toward new fundamentaltechnologies and techniques promoting efficient andjoint use of the research infrastructures.

The scope of the project covers all aspects of seismicengineering testing, with the participation of eight reactionwall pseudodynamic (PsD) facilities, ten shake table labs,EU’s unique tester of bearings or isolators, EU’s two majorcentrifuges and an instrumented site for wave propagationstudies.

Participants

The workshop will be attended by researchers andscientists from European and international researchinfrastructures on earthquake engineering, includingshaking table, reaction wall, centrifuge and on-site testingfacilities.

The workshop will also be attended by users of SERIESinfrastructures within the Transnational Access activities ofthe project.

Participants from other related FP7 Projects as well asfrom other international research infrastructures/networksare welcome.

Event Registration

Participants are requested to register at the JRCregistration site https://jrc-meeting-registration.jrc.ec.europa.eu/ by 30 April 2013.

Venue, dates and social events

The workshop will be held in Bldg. 58c, Auditorium, JointResearch Centre, European Commission, Ispra (Va), Italyon 28-30 May 2013.

The organizing Committee invites all participants to threedinners on 28, 29 and 30 May.

SERIES Concluding Workshop -

Joint with US-NEES

“Earthquake Engineering Research

Infrastructures”

JRC-Ispra, May 28-30, 2013

In memory of Prof. Roy Severn


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Attendance Fees

There will be no registration fee for the Workshop. Withthe exception of invited participants, attendees areresponsible for their own travel, accommodation andsubsistence costs. All lunches and social dinners heldduring the workshop will be offered free of charge, as wellas all transportation from/to the main airports and trainstations to/from the hotels, meeting places and socialevents.

The Workshop secretariat will provide to participants anyfurther information about travel and accommodationarrangements.

Workshop Material

Relevant Workshop material will be distributed at theWorkshop. All presentations will be available for downloadfrom the SERIES website after the Workshopwww.series.upatras.gr

Workshop Organising Committee

Fabio Taucer - Joint Research CentreMichael Fardis, Dionysis Biskinis, Vassia Vayena -University of PatrasJulio Ramirez - Purdue University, NEES, USA

Workshop Scientific Committee

Michael Fardis – University of PatrasFabio Taucer – Joint Research CentreJulio Ramirez – Purdue University, NEES, USAEduardo Cansado Carvalho – GAPRES SAPaolo E Pinto – Università di Roma La SapienzaAndré Plumier – Université de LiègeEnrique Alarcón – Universidad Politécnica de MadridKostantin Meskouris – RWTH Aachen University

Workshop Proceedings

Full papers will be submitted by 30 June 2013, will bepeer-reviewed by two reviewers and should be of journalcalibre. The Proceedings will be published by a reputedpublisher. Contributing authors will receive acomplimentary copy of the Proceedings.

Special Session on HybridSimulation

A Special Session on Recent Advances in HybridSimulations is organised. The scope of this Special Sessionis to present recent advances on numerical methods,testing techniques and control strategies from a hybridsimulation perspective. Major focus will be given toimplementation aspects of software and hardware as wellas to applications to significant case studies.

With the Support of

European Community’s FP7/2007-2013 Project SERIES(“Seismic Engineering Research Infrastructures forEuropean Synergies”) under grant agreement n° 227887.

Secretariat

Claudia CarnielEuropean Commission - Joint Research Centre (JRC)TP 480, Via E. Fermi, 2749I-21027 Ispra (VA), ItalyTel.: +39 0332 786062, Fax: +39 0332 789049Email: [email protected]

www.series.upatras.gr


mailto:[email protected]



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Programme


08:4509:00 Registration

09:0009:05 Welcome (Artur Pinto, Fabio Taucer – JRC)

Hybrid Testing(Chairs: Oreste Bursi, Shirley Dyke)

09:0509:10 Opening remarks (Oreste Bursi)

09:1009:30

Towards faster computations and accurateexecution of real-time hybrid simulationMosalam KM, Günay S

09:3009:50

Robust integrated actuator control strategyfor real time hybrid simulationOu G, Dyke SJ, Wu B

09:5010:10

Real-time earthquake simulation usingforce controlled actuatorsNakata N, Krug E

10:1010:30

Assessment of the seismic behaviour of aretrofitted old RC highway bridge throughPsD testingBursi OS, Ceravolo R, Di Sarno L, Erdik M,Paolacci F, Sartori M, Pegon P

10:3010:45 Coffee Break

10:4511:05

Pseudo-dynamic testing with non-linearsubstructuring of a reinforced concretebridge based on system identification andmodel updating techniquesAbbiati G, Bursi OS, Cazzador E, Mei Z,Paolacci F, Pegon P

11:0511:25

Numerical tools for the reduction ofcomplex dynamic modelsAbbiati G, Bursi OS, Cazzador E, Mei Z

11:2511:45

Geographically distributed continuoushybrid simulation tests using shaking tablesObón Santacana F, Dorka UE

11:4512:05

Pseudo-dynamic testing of a piping systembased on model reduction techniquesReza MS, Abbiati G, Bonelli A, Bursi OS

12:0512:25

Monolithic time-integration algorithms forHamiltonian systems suitable for real-timehybrid simulationsAbbiati G, Bonelli A, Bursi OS, Reza MS

12:2512:45

Advanced hybrid simulation frameworks forcivil structuresPhillips BM, Spencer BF Jr.

12:4513:40 Lunch Break

13:4014:00

A support platform for distributed hybridtestingLamata Martinez I, Obón Santacana F,Williams MS, Blakeborough A, Dorka UE

14:0014:20

Dynamic substructuring for soil structureinteraction using a shaking tableTang Z, Dietz M, Li Z, Taylor C

14:2014:40

Real-time hybrid testing for soil-structureinteraction: An adaptive signal processingframeworkDertimanis VK, Mouzakis HP, Psycharis IN

14:4015:00

Towards an implementation of the FHTtechnique for SSI systems using nonlinearmacroelementsChatzigogos CT, Dietz M, Pecker A,Tang Z

15:0015:20 Roundtable discussion


SERIES Transnational Access to CentrifugeFacilities(Chairs: Gopal Madabhushi, Khalid Mosalam)

15:3515:40 Opening remarks (Gopal Madabhushi)

15:4016:00

Centrifuge modeling of dynamic behavior ofbox-shaped underground structures in sandÜlgen D, Sağlam S, Özkan MY, Chazelas J-L

16:0016:20

Investigation of the seismic behaviour ofshallow rectangular underground structuresin soft soils using centrifuge experimentsTsinidis G, Rovithis E, Pitilakis K,Chazelas J-L

16:2016:40

Investigation of several aspects affectingthe seismic behaviour of shallowrectangular underground structures in softsoilsTsinidis G, Heron C, Madabhushi SPG,Pitilakis K, Stringer M

16:4017:00

Experimental verification of shallowfoundation performance under earthquake-induced liquefactionKaramitros DK, Cilingir U, Bouckovalas GD,Madabhushi SPG, Papadimitriou AG,Haigh SK

17:0017:20

Centrifuge modelling of the performance ofliquefaction mitigation measures for shallowfoundationsMarques A, Coelho P, Haigh SK,Madabhushi SPG

17:2017:40

Centrifuge modeling of pairs of flexibleretaining walls in saturated sand underseismic actionsAversa S, De Sanctis L, Maiorano RMS,Tricarico M, Viggiani G, Conti R,Madabhushi SPG, Stringer M, Heron C

17:4018:00

Experimental and numerical investigationsof nonlinearity in soils using advancedlaboratory-scaled models: An application tothe Rome historical centreBozzano F, Bretschneider A, Giacomi AC,Martino S, Scarascia Mugnozza G, EscoffierS, Lenti L, Chazelas J-L, Favraud C, Macé D


20:00 Social Dinner


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US-NEES developments(Chairs: Julio Ramirez, Artur Pinto)

09:0009:05 Opening remarks (Julio Ramirez)

09:0509:25

The George E. Brown, Jr., Network forEarthquake Engineering Simulation (NEES):Accelerating improvements in seismicdesign and performance by serving as aglobal collaboratory for discovery andinnovationRamirez J

09:2509:45

Promoting re-use of EarthquakeEngineering data through the NEEShubBrowning J

09:4510:05

Re-use of experimental earthquake data forresearch: Three illustrative examplesVan de Lindt JW

10:0510:25

Communicating earthquake engineering:The education, outreach, and trainingactivities of the George E. Brown, Jr.Network for Earthquake EngineeringSimulationsFossum B

10:2510:45

Damping estimation from seismic recordsBernal D


SERIES Networking Activities: DistributedDatabase and Qualification of ResearchInfrastructures(Chairs: Pierre Pegon, JoAnn Browning)

11:0011:05 Opening remarks (Pierre Pegon)

11:0511:25

A faceted lightweight ontology forearthquake engineering research projectsand experimentsHasan MR, Farazi F, Bursi OS, Reza MS

11:2511:45

The SERIES Virtual Database:Architecture and implementationLamata Martinez I, Ioannidis I, Fidas C,Williams M, Pegon P

11:4512:05

The SERIES Virtual Database:Exchange format, local DBs and centralportal interfaceBosi A, Kotinas I, Martinez IL, Bousias S,Chazelas J-L, Dietz M, Hasan MR, MadabhusiSPG, Prota A, Blakeborough T, Pegon P

12:0512:25

Qualification of seismic research testingfacilities in EuropeZola M, Taucer F

12:2512:45

Roundtable discussion(US-NEES developments and SERIESΝetworking Αctivities)

12:4513:45 Lunch Break

SERIES Transnational Access to Shaking TableFacilities on masonry, RC and steel structures(Chairs: Alberto Pavese, Brian Phillips)

13:4513:50 Opening remarks (Alberto Pavese)

13:5014:10

Full scale testing of modern unreinforcedthermal insulation clay block masonryhousesLu S, Jäger A, Mendes L, Campos Costa A,Candeias P, Coelho E, Degée H, Mordant C,Sendova V, Rakicevic ZT, Tomazevic M

14:1014:30

Assessment of innovative solutions fornon-load bearing masonry enclosuresLeite J, Lourenço PB, Vintzileou E,Palieraki V, Correia AA, Candeias P,Campos Costa A, Coelho E

14:3014:50

Seismic behaviour of L- and T-shapedunreinforced masonry shear wallsMordant C, Dietz M, Vasseur L, Degée H

14:5015:10

Shake table testing of a half scaled RC-URMwalls structureTondelli M, Petry S, Lanese I, Beyer K,Peloso S

15:1015:30

Experimental and numerical investigation oftorsionally irregular RC shear wall buildingswith Rutherma breakersYakut A, Le Maoult A, Richard B, RagueneauF, Atanasiu GM, Scheer S, Diler S

15:3015:50

Assessment of the seismic response ofconcentrically-braced steel framesBroderick BM, Hunt A, Mongabure P,LeMaoult A, Goggins JM, Salawdeh S,O’Reilly G, Beg D, Moze P, Sinur F,Elghazouli AY, Plumier A


SERIES Transnational Access to Shaking TableFacilities on wood structures / General onExperimental facilities(Chairs: Alberto Pavese, Narutoshi Nakata)

16:0516:25

Seismic performance of laminated woodframes with moment connections underseismic loads: Experimental investigationKasal B, Heiduschke A, Pospisil S,Urushadze S, Zembaty Z

16:2516:45

Investigation of seismic performance ofmulti-storey timber buildingsPiazza M, Tomasi R, Campos Costa A,Candeias P

16:4517:05

Experimental study on seismic performancesof precast concrete shear wall with jointconnecting beamLu X, Wang D, Zhao B

17:0517:25

Full-scale PsD testing of the SAFECASTthree-storey precast concrete buildingsBournas D, Negro P, Molina F-J

17:2517:45

Experimental earthquake engineeringresearch in LNEC: Contribution to globalseismic performance assessment ofstructuresCoelho E, Campos Costa A, Candeias P,Mendes L, Correia A


20:00 Social Dinner


69


Analytical and Experimental work on soil structureinteraction, wave propagation and field testing,including SERIES Transnational Access to ShakingTable Facilities(Chairs: Alain Pecker, Dionisio Bernal)

09:0009:05 Opening remarks (Alain Pecker)

09:0509:25

Caisson foundations subjected to seismicfaulting: Reduced-scale physical modellingAnastasopoulos I, Zarzouras O,Georgarakos T, Drossos V, Gazetas G

09:2509:45

Effect of soil structure interaction on highermodes participationMirfattah SA, Mirfattah SK

09:4510:05

Estimation of soil structure interactioneffects, considering the frequency contentof the motionMirfattah SH, Mirfattah SA

10:0510:25

Development of new infinite element fornumerical simulation of wave propagationin soil mediaSesov V, Edip K, Cvetanovska J


10:4011:00

Design and construction of laminarcontainer for 1-g shaking table testsSesov V, Cvetanovska J, Edip K,Rakicevic ZT

11:0011:20

Analysis of the dynamic behavior of squatsilos containing grain-like materialsubjected to shaking table testsFoti D, Ivorra S, Trombetti T, Silvestri S,Gasparini G, Taylor C, Dietz M

11:2011:40

Study of multi-building interactions andsite-city effect through an idealizedexperimental modelSchwan L, Boutin C, Dietz M, Padron LA,Bard P-Y, Castellaro S, Ibraim E, Maeso O,Aznárez JJ, Taylor C

11:4012:00

EuroProteas: A full-scale experimentalfacility for soil-foundation-structureinteraction studiesPitilakis D, Rovithis E, Anastasiadis A,Pitilakis K


12:2013:15 Lunch break

13:1514:15 Visit to the ELSA laboratory

Analytical and Experimental Techniques / SERIESTransnational Access to Reaction Wall Facility(Chairs: Fabio Taucer, John Van de Lindt)

14:1514:20 Opening remarks (Fabio Taucer)

14:2014:40

In-situ seismic performance tests of ascoured bridgeChang K-C

14:4015:00

Validation of a visual deformationmeasurement systemBinbir E, Demir C, Ispir M, Ilki A

15:0015:20

Development of wireless sensors for shaketable and full scale testing and healthmonitoring of structuresRakicevic ZT, Markovski I, Filipovski D,Micajkov S, Garevski M

15:2015:40

Recent advances in seismic design of RC tallbuildings using ultra-high-strengthmaterials in TaiwanHwang S-J

15:4016:00

Refined and simplified numerical models ofan isolated old highway bridge for PsD testsPaolacci F, Alessandri S, Mohamad A,Corritore D, Derisi R

16:0016:20

Full-scale experimental validation of dualeccentrically braced frame with removablelinksStratan A, Dubina D, Ioan A, Taucer F,Poljansek M



16:5017:20

Conclusions and Recommendations(Michael Fardis, Julio Ramirez,SERIES External Scientific Committee)

17:2017:30 A Tribute to Roy Severn (Colin Taylor)

20:00 Social Dinner

Documents

SERIES Concluding Workshop - Joint with US-NEES ......Leite J, Lourenço PB, Vintzileou E, Palieraki V, Correia AA, Candeias P, Campos Costa A, Coelho E 37 Seismic behaviour of L-