TheDynamicInteractionofSoilandStructure THE DYNAMIC …diss-co.it/wordpress_5/wp-content/uploads/2015/05/DISS_10_tot_rid.pdf · TheDynamicInteractionofSoilandStructure ... 89 Dynamic

A08322

The Dynamic Interaction of Soil and Structure

The phenomena arising from the dynamic interaction of soil and structure repre-sent a research field that encompasses a wide range of scientific sectors, all of whi-

ch are important in the definition of methodologies for analysis and design. This takeson particular significance in light of the tragic events connected to the earthquake inL’Aquila on 6th April 2009. This book gathers together the research and design propo-sals put forward by experts in the fields of hydraulics, geology, geothecnics, structu-ral and transportation engineering, geophysics, physics, archaeologists and architects.

Contributions of Raffaele Adinolfi Falcone, Dario Albarello, Sara Amoroso, Antonella Amoruso, Riccardo Mario Azzara,Francesco Benedettini, Francesco Bergamaschi, Etienne Bertrand, Marcello Bianca, Paola Bordoni, Giacomo Buffarini,Fabrizio Cara, Valentina Carucci, Arrigo Caserta, Alfredo Maria Ceci, Maurizio Cerone, Paolo Clemente, Rocco Cogliano,Luca Crescentini, Francesco Crisi, Giovanna Cultrera, Alberto Delladio, Adriano De Sortis, Giuseppe Di Giulio, RoccoDitommaso, Mauro Dolce, Gino D’Ovidio, Anne–Marie Duval, Antonella Falgiani, Antonio Fodarella, Maria RosariaGallipoli, Vincenzo Gattulli, Aladino Govoni, Marco Lepidi, Enrico Lunedei, Mauro Manetta, Andrea Marchetti, DiegoMarchetti, Silvano Marchetti, Sandro Marcucci, Fabrizio Marra, Giuliano Milana, Paola Monaco, Marco Mucciarelli,Yutaka Nakamura, Marco Paolessi, Barbara Parisse, Marco Petitta, Francesco Potenza, Stefania Pucillo, Julie Régnier,Gaetano Riccio, Antonio Rovelli, Sergio Rusi, Antonello Salvatori, Donato Sciannamblo, Michele Spizzico, Marco Tallini,Ferdinando Totani, Gianfranco Totani, Gianfranco Valente, Marco Vona.

Gino D’Ovidio is Aggregate Professor of Transportation Engineering at the Univer-sity of L’Aquila. His research activity has concerned mainly non–conventional tran-

sport systems. His most significant scientific result is the technology definition and rea-lization of UAQ4 magnetic levitating train with resistance free to motion, except ae-rodynamic drag. He is author of more than 70 articles and several patents.

Yutaka Nakamura is President of System and Data Research and Visiting Professor ofTokyo Institute of Technology. His research activity concerns mainly EEW and vul-

nerability assessment for structures and ground. His developing systems are the first ac-tual EEW system UrEDAS, Compact UrEDAS, FREQL and AcCo, and his developing te-chniques are H/V spectral ratio and K–value methods.

Antonio Rovelli is Director of Research at INGV, Department of Seismology and Tec-tonophysics. His interest fields are strong–motion seismology and models of ground

shaking. He is author of more than 70 papers on ISI journals.

Gianfranco Valente is Professor of Structural Engineering at L’Aquila University. Hisresearch activity concerns mainly non–linear analysis, for geometry and materials,

static and dynamic. He is author of about 100 papers.

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ISBN 978-88-548-3693-x

COVERBY:STUDIO

BG

TheDynam

icInteraction

ofSoiland

Structureedited

byG.D’Ovidio,Y.N

akamura,A

.Rovellli,G.Valente

PROCEEDINGS OF THE WORKSHOP DISS_10,L’AQUILA, 19 MARCH 2010

THE DYNAMICINTERACTION OF SOIL

AND STRUCTURE

Edited byGino D’Ovidio

Yutaka NakamuraAntonio Rovelli

Gianfranco Valente

UNIVERSITÀ DEGLI STUDI DI L’AQUILADipartimento di Ingegneria delle Stuturedelle Acque e del Terreno

copertina New.qxp:A 170 mastro copertine 3-03-2011 10:35 Pagina 1

A08322

The Organizing Committee was composed by:Francesco Benedettini, Dante Galeota, Vincenzo Gattulli, Antonio Rovelli,Antonello Salvatori, Marco Tallini, Gianfranco Totani, Gianfranco Valente.

The papers presented in this Proceedings were selected by the Scientific Committee:Dario Albarello, Arrigo Caserta, Alberto Delladio, Gino D’Ovidio, Aladino Govoni, GiulianoMilana, Fabrizio Marra, Marco Mucciarelli.

The Workshop received supports by:University of l’Aquila and its Dipartimento di Ingegneria delle Strutture Acque e Terreno(DISAT) , Società Roma Metropolitane s.r.l., Istituto Nazionale di Geofisica (INGV), Agenzianazionale per le nuove tecnologie, l’energia e lo sviluppo economico sostenibile (ENEA).

Assistance for international relationships:Aki Takizawa

The picture in the frontal covering represents: the Church of “Santa Maria” in Paganica(L’Aquila) damaged by the carthquake on 6 April 2009. It was extracted from the enclo-sed paper by:Prof. Mauro Dolce.



AND STRUCTURE



Gianfranco Valente

Copyright © MMXARACNE editrice S.r.l.

[email protected]

via Raffaele Garofalo, 133 A/B00173 Roma(06) 93781065

ISBN 978–88–548–3693–8

No part of this book may be reproduced in any form,by print, photoprint, microfilm, microfiche, or any other means,

without written permission from the publisher.

1st edition: February 2011

5

Index

7 Introduction

9 The H/V technique and example of its application for l’Aquila and

Rome areas Yutaka Nakamura

23 Modelling of ambient vibration wavefield for passive seismic

prospectingDario Albarello, Enrico Lunedei

37 Site characterization by seismic dilatometer (SDMT) in the area of L’AquilaSara Amoroso, Diego Marchetti, Silvano Marchetti, Paola Monaco,Ferdinando Totani, Gianfranco Totani

63 Base isolated buildings: economic evaluatations Paolo Clemente, Giacomo Buffarini

75 Seismic response of two couples of similar buildings in Pettino-L’Aquila during the 6 April 2009 earthquakeFrancesco Benedettini, Adriano De Sortis, Giuliano Milana

89 Dynamic interaction of soil and structure by rail traffic Arrigo Caserta, Maurizio Cerone, Francesco Crisi, Alberto Delladio, Gino D’Ovidio, Aladino Govoni, Fabrizio Marra, Yutaka Nakamura, Antonio Rovelli, Gianfranco Valente

109 The 6 April 2009 Abruzzi EarthquakeMauro Dolce

123 Seismic site response in L’Aquila city center and in suburban areas Giuliano Milana, Riccardo Mario Azzara, Francesco Bergamaschi, Etienne Bertrand, Paola Bordoni, Fabrizio Cara, Rocco Cogliano, Giovanna Cultrera, Giuseppe Di Giulio, Anne-Marie Duval, Antonio Fodarella, Sandro Marcucci, Stefania Pucillo, Julie Régnier, Gaetano Riccio

137 Extensive seismic survey with passive prospecting techniques: the L'Aquila earthquake example Dario Albarello, Maria Rosaria Gallipoli, Marcello Bianca

153 Earthquake Early Warning and Realtime Earthquake Disaster PreventionYutaka Nakamura

6

Vincenzo Gattulli, Marco Lepidi, Francesco Potenza, Alfredo M. Ceci

181 Damage level vs fundamental frequencies of damaged RC buildings Rocco Ditommaso, Maria Rosaria Gallipoli, Marco Mucciarelli, Marco Vona

189 Analisi meccanica del danno di elementi non strutturali Antonello Salvatori

195 In-depth understanding of 2009 L'Aquila earthquake: the contribution of Gran Sasso physico-chemical groundwater data Raffaele Adinolfi Falcone, Antonella Amoruso, Valentina Carucci, Luca Crescentini, Antonella Falgiani, Mauro Manetta, Andrea Marchetti, Marco Paolessi, Barbara Parisse, Marco Petitta, Sergio Rusi, Donato Sciannamblo, Michele Spizzico, Marco Tallini

219 Authors index

167 Optimization of viscous coupling between adjacent structures excited by ground motion

7

Introduction

It is a great pleasure for me to open this workshop on the dynamic interaction of soil-structure.

First of all I would like to welcome and thank Professor Yutaka Nakamura.

Professor Nakamura is one of the world’s leading scientists in engineering seismology.

He is President of the System and Data Research Company and a visiting professor at the Tokyo Institute of Technology.

Our special thanks go to the Organizing Committee and in particular, Professor Gianfranco Valente, who made this important event possible.

One of the most important causes of damage to structures is inaccuracy in estimating earthquake excitation characteristics during the design phase.

It is well known that many of the buildings in L'Aquila were built well over a hundred years ago. Hence the earthquake acted upon a variety of structures, some only designed for structural loads whilst others with no structural design at all. It is therefore reasonable to expect that the majority of structures experienced some damage.

The soil conditions of the area and the geological formation had a significant effect on the distribution of the structural damage.

The information that can be gathered from studies, symposia and workshops on microzonation and dynamic soil-structure interaction will contribute to more accurate estimations of expected ground motion caused by earthquakes and clarify governing principles for the structural rehabilitation of damaged buildings.

This is the main focus of this important workshop. In concluding my speech, I would like to wish you all a fruitful and

pleasant stay in our University.

The Director of Dpt DISAT at l’Aquila University: Dante Galeota

8

This book is a collection of papers from the workshop “The Dynamic Interaction of Soil and Structure” (DISS_10) held in the city of L’Aquila approximately a year after the destructive earthquake of 6 April 2009. The workshop was organized by the University of L’Aquila, and supported by the Società Metropolitane di Roma, INGV and ENEA, with two important aims: the first to promote dialogue between scientists from differing disciplines (geologists, seismologists, engineers) to establish a preliminary picture of the earthquake and its impact on the territory; and the second to tackle more general problems concerning the safety of historical cities. In the debates that followed, unresolved problems were defined and innovative directions for new research and new perspectives proposed, with particular reference to monumental heritage. One of the greatest challenges undertaken by seismologists and earthquake engineers in the second half of the last century was the study of ground motion radiated by large earthquakes and its interaction with building structure. The slow but significant advance of research into experimental measurements, theoretical explanations and numerical modeling has provided the scientific community with extremely useful tools for the third millennium. Following the earthquake in April 2009 in L’Aquila, it has been shown that a significant amount of important information can be gathered after an earthquake. This information was presented during the workshop and formed the basis of a number of constructive discussions. Amongst the innovative tools discussed was the use of ambient vibrations which are particularly important in seismology and earthquake engineering because of their low cost and availability. However, the definition of a largely accepted theoretical basis is still controversial. This issue monopolized a significant percentage of presentations but further innovative ideas and models are also proposed in this book. The broad spectrum of contributions from across the scientific community presented in this book are a reflection of the specialized approach that is being adopted in this field.

The Papers from the Proceedings of the Workshop are published in the same order as they were presented during the Workshop. The Editors: Gino D’Ovidio, Yutaka Nakamura, Antonio Rovelli and Gianfranco Valente L’Aquila, 30 November 2010.

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1 System and Data Research, Tokyo, Japan

2 Tokyo Institute of Technology, Yokohama, Japan

9

The H/V Technique and Example of its Application for

L’Aquila and Rome Areas Yutaka Nakamura1, 2

Abstract The H/V technique is an estimation tool for the local site effect as not only the predominant frequency but also the amplification factor. Both microtremor and strong motion consist of various kinds of waves as P-wave, S-wave, Rayleigh wave, Love wave and so on, so the spec-trum derived from microtremor or strong motion shows many peaks corresponding to these wave components. From the viewpoint of the seismic disaster mitigation, it is important to pick out S-wave from microtremor and investigate its characteristics because the severe damage is mainly caused by S-wave. Although it is fine way to esti-mate the S-wave structure of the surface ground layers from the char-acteristics of Rayleigh wave, this technique requires not only a precise setup of the measurement points but also complex analysis. On the other hand, the H/V technique is established as a direct approach for the site amplification estimation, so it is easy to apply for the various ground condition. This paper shows the scheme of the H/V technique and its application for L’Aquila and Rome areas.

1. Introduction The H/V technique is an estimation tool for the local site effect as not only the predominant frequency but also the amplification factor. Both microtremor and strong motion consist of various kinds of waves as P-wave, S-wave, Rayleigh wave, Love wave and so on, so the spec-trum derived from microtremor or strong motion shows many peaks corresponding to these wave components. From the viewpoint of the

The dynamic interaction of soil and structureISBN 978–88–548–3693–8DOI 10.4399/97888548369381pag. 9–22 (febbraio 2011)

_______________________________

1 Dipartimento di Scienze della Terra, Università di Siena, Via Laterina 8, 53100 Siena, Italia

23

Modelling of ambient vibration wavefield for passive seismic prospecting

Dario Albarello1, Enrico Lunedei1

Abstract Most of local variations in the earthquake damage level are induced by resonance phenomena within soft sedimentary cover overlying a rigid bedrock. To reveal the presence of this effect before the earth-quake, experimental techniques exploiting ambient vibrations are to-day widely used. They allow, by means specific inversion protocols, to determine, from rapid and cost-effective field measurements, the subsoil mechanical structure, from which amplification effect can be evaluated. In order to allow a correct inversion of ambient vibration measurements, a physical interpretation of observed features is man-datory. This contribution presents and illustrates the results of numeri-cal analysis carried out by considering a new physical model for am-bient vibrations measured at the surface of the Earth, in the frequency range of engineering interest (0.5-20 Hz). The basic hypothesis is that the observed wavefield is the result of the activation of a uniform dis-tribution of random independent point-like harmonic sources, located at the surface of a layered weakly dissipative Earth. In this framework, it is possible to evaluate average spectral features of vibration ex-pected at a receiver, without any restriction about seismic phases of concern. By using this model, a parametric exploration of the random vibration wavefield was carried out, showing that contribution of the different seismic phases changes, as a function of the frequency of concern, with the subsoil mechanical configuration and with the dis-tribution of sources around the receiver. These results are compatible with major findings of experimental studies.


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1 University of L'Aquila, Italy.

2 Studio Prof. Marchetti, Roma, Italy.

37

Site characterization by seismic dilatometer (SDMT) in the area of L'Aquila

Sara Amoroso1, Diego Marchetti2, Silvano Marchetti2, Paola Monaco1, Ferdinando Totani1, Gianfranco Totani1

Abstract The seismic dilatometer (SDMT) is the combination of the standard

flat dilatometer (DMT) with a seismic module for measuring the shear wave velocity VS. This paper presents the most significant results ob-tained by SDMT in the area of L'Aquila following the April 6, 2009 earthquake. 1. Introduction

The seismic dilatometer (SDMT) is the combination of the tradi-tional "mechanical" flat dilatometer (DMT) introduced by Marchetti (1980) with a seismic module placed above the DMT blade. The SDMT module is a probe outfitted with two receivers, spaced 0.5 m, for measuring the shear wave velocity VS. From VS the small strain shear modulus G0 may be determined using the theory of elasticity.

The SDMT equipment, test procedure and interpretation are briefly described in the paper. Detailed information and comments on SDMT results and applications can be found in previous papers, in particular in Marchetti et al. (2008). Information on the mechanical DMT, not described in this paper, can be found in the comprehensive report by the ISSMGE Technical Committee TC16 (2001).

This paper comments on the most significant results obtained by seismic dilatometer tests executed in the period 2009-2010 at several sites in the area of L'Aquila. Some of these tests were carried out in the first months following the April 6, 2009 earthquake, as part of site


63

Base Isolated Buildings: Economic Evaluations Paolo Clemente1, Giacomo Buffarini2

AbstractThe new Italian Technical Code for Structures allows reducing the

seismic action in the superstructure of seismic isolated buildings. This translates in a significant reduction of the construction cost, which could also balance the increase due to the isolation system. In this pa-per the convenience in using seismic isolation also for ordinary build-ing is tested by referring to a real simple case of reinforced concrete structure. Elastomeric isolators and sliders are considered. A suitable procedure for the design of a building with seismic isolation is first proposed. Then the main results of a wide numerical investigation are shown.

1 ENEA, Rome, Italy 2 ENEA, Rome, Italy


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1 University of L’Aquila, Italy.

2 Department of Civil Protection, Italy.

3 INGV, National Institute of Geophysics and Vulcanology, Italy.

75

Seismic response of two couples of similar buildings in Pettino-L’Aquila during the 6 April 2009 earthquake Francesco Benedettini1, Adriano De Sortis2 and Giuliano Milana3

Abstract During the 6 April earthquake in L’Aquila, two couples of similar buildings belonging to the same urban intervention exhibited a dra-matically different response. Two of them collapsed while the others, apparently very similar to the preceding ones, survived. In each couple one building showed a soft storey collapse mechanism while the other was characterized by a damage pattern not so strong as expected con-sidering the similarity with the collapsed one. After recalling the main aspects of the soft storey collapse mechanism, some significant col-lapse of buildings in L’Aquila will be discussed and, among them, the case in Pettino will be deeply analyzed. The local site-amplification factor due to the geology played a key role in the dynamic evolution during the earthquake. Dynamical experimental tests on the site and on the survived structures permitted the validation of FE linear and nonlinear models used to give an explanation of the different evolu-tion


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1 University “la Sapienza” Roma, Italy.

2 University of l’Aquila, Italy.

3 INGV, Italy.

4 SDR, Tokyo, Japan.

89

Dynamic interaction of soil and structure by rail traffic

Arrigo Caserta3, Maurizio Cerone 1, Francesco Crisi 2, Alberto Delladio 3, Gino D’Ovidio 2, Aladino Govoni 3, Fabrizio Marra 3, Yutaka Nakamura 4, Antonio Rovelli 3

and Gianfranco Valente 2

Abstract This paper presents and illustrates the results of numerical analysis methodology focused to measure and monitor weak vibrations affect-ing buildings, produced by railway traffic. The analysis method pro-poses the use of two different three-dimensional models connected functionally. The first model, a “wagons-track” multi-bodies model analysis based, instantaneously provides the strengths in the rail-sleeper connections created by the transit of wagons/trains, which vary according to load and use. These strengths are the input for the second model, finite element analysis based, which evaluates the vibrations of the “soil-structure” interaction. Motion [s(t), v(t), a(t)] and tensorial [ (t), (t )] characteristics for all the nodes and elements of the models can be used to extract the vibration characteristics and, in the future, to carry out the earthquake analysis. This analysis methodology was ap-plied to the archaeological zone of Rome comprising the Colosseum and the Arch of Constantine which is crossed by the underground railways B and C. The results are presented and discussed


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1 Civil Protection Department, Italy.

109

The 6 April 2009 Abruzzi Earthquake Mauro Dolce1

Abstract The activities initiated after the Mw 6.3 Abruzzi Earthquake of April 6,

2010 can be distinguished in three phases: emergency, post-emergency and reconstruction. Although they are not exactly sequential, because of some overlapping between them, it is useful to use such a scheme, also in relation to the objective to be reached at the end of each of them. The management of the emergency and post-emergency phases was relied upon a governmen-tal commissioner, that, until January 31, 2010, was the chief of the Civil Protection Department. From February 1, 2010, a new commissioner was enforced, with the full responsibility of the reconstruction phase. In this pa-per the main problems and solutions dealt with in the three phases are de-scribed, with a main concern for engineering aspects.

1. Introduction

At 3:32 a.m. of April 6, 2009, a Mw 6.3 earthquake struck the town of L’Aquila and the surrounding in Central Italy, causing 308 casualties. The shake was characterized by maximum MCS Intensity IX-X and maximum peak ground acceleration 0.66g. The mainshock was preceded by a swarm, started at the end of 2008. The mainshock was followed by thousands of af-tershocks. Within the first three weeks, over 4,000 aftershocks occurred, 7 of which with magnitude greater than Mw 5.0. The effects were devastating, due to the population density in the stricken area, the epicenter being located just few kilometers far from the centre of L’Aquila, a city with about 75000 inhabitants and an important historical centre. Many vulnerable buildings were severely damaged and collapsed, with a tremendous impact on the cul-tural heritage.

2. Emergency management


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1 Istituto Nazionale di Geofisica e Vulcanologia, Roma, Italy

2 Cete Méditerranée, Nice, France

3 Dipartimento Protezione Civile, Roma, Italy

123

Seismic site response in L’Aquila city center and in sub-urban areas

Giuliano Milana1, Riccardo Mario Azzara1, Francesco Bergamaschi1,Etienne Bertrand2, Paola Bordoni1, Fabrizio Cara1, Rocco Cogliano1,

Giovanna Cultrera1, Giuseppe Di Giulio1, Anne-Marie Duval2,Antonio Fodarella1, Sandro Marcucci3, Stefania Pucillo1,

Julie Régnier2, and Gaetano Riccio1

Abstract This paper presents and illustrates the seismic data acquisition and analyses performed during the microzoning activities in L’Aquila city centre and suburban areas. A big amount of seismic stations were in-stalled shortly after the April 6th magnitude 6.3 events with the goal of investigating the possible role of site amplification on ground motion. The installed instruments were able to record a big amount of both microtremor and aftershocks data that were analyzed using standard spectral techniques, HVNSR for microtremor and SSR for after-shocks. As a final result of our analyses we present data concerning the resonant frequency fo of the surface soft soil layers along with the amplification factor Fa derived by response spectra analysis. The seismic data can offer a good support in understanding the geometry of surface sedimentary layers and to define the areas that experienced the highest seismic amplification. These factors can play an important role in activities related to the reconstruction of L’Aquila area to be accomplished in the next years.


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1 DST, Università di Siena, Italy.

2 I.M.A.A.-C.N.R., Tito Scalo (PZ), Italy.

3 Di.S.G.G., Università della Basilicata, Potenza, Italy

137

Extensive seismic survey with passive prospecting tech-niques: the L'Aquila earthquake example

Dario Albarello1, Maria Rosaria Gallipoli2, Marcello Bianca3

Abstract Seismic microzoning requires methodological approaches to the dynamic characterization of the shallow subsoil that are quite different from those commonly used in support of building design. In particu-lar, microzoning requires survey procedures that have to be applied extensively over large land extensions in support of urban planning, or, as in the case post-event earthquakes scenarios, to manage recon-struction and locate provisional structures. In this context cheap and easy to apply prospecting tools are required. And, seismic prospecting techniques based on the analysis of ambient vibrations may provide very important contribution as the recent experience of the L’Aquila earthquake has shown. In the text, basic methodological aspects of these procedures are shortly outlined along with very simple and ef-fective interpretation tools. An example of application of these proce-dures after the recent L’Aquila earthquake is described and discussed.

1. Introduction


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1 System and Data Research, Tokyo, Japan

2 Tokyo Institute of Technology, Yokohama, Japan

Earthquake Early Warning and Realtime Earthquake Disaster Prevention

Yutaka Nakamura1, 2

Abstract An EEW, Earthquake Early Warning, is required to trigger realtime earthquake disaster prevention. However, it is important to avoid too much trust in EEW for the disaster prevention. This paper describes the concept of an EEW and gives a brief history which eventually led to the development of the UrEDAS, the Urgent Earthquake Detection and Alarm System, the first operational P-wave early warning system, and its new generation system FREQL, Fast Response Equipment against Quake Load. A real-world example of disaster prevention by this system is also described. As a specific example to review the ef-fect for the disaster prevention, the leading time by FREQL is esti-mated using the strong motion records of the 2009 L’Aquila earth-quake. Finally, the role of information in earthquake disaster preven-tion will be discussed.

1. Introduction Obviously, the basic of the earthquake disaster prevention is the strengthening structures and buildings against the earthquake load. The devastations caused by the 2009 L’Aquila earthquake were mainly based on the lack of the strength of the many facilities and structures. It is necessary to escape from the situation as meeting with a large earthquake motion to survive from unexpected damage. The idea to minimize the damage of earthquakes by developing an early warning system was first published by Cooper in 1868 [1] at San Francisco. However, Cooper’s idea was never realized and basically forgotten. About 100 years later, another but similar concept of earth-quake warning was published [2] in Japan. At the same time, many in-

153


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Dipartimento delle Strutture delle Acque e del Terreno, Università dell’Aquila, Italy.

167

Optimization of viscous coupling between adjacent structures excited by ground motion

Vincenzo Gattulli, Marco Lepidi, Francesco Potenza, Alfredo M. Ceci

Abstract The effects of a dissipative coupling between adjacent structures subjected to synchronous imposed ground motion have been investi-gated. The study evidences the existence of an optimal pair of the de-sign parameters characterizing a passive interconnection described through a Kelvin-Voigt model. The assumed optimization criterion corresponds to the maximum damping reachable in the parameter space associated to a simple 2dof dynamic model which describes the linear interaction. The analysis of the displacement transfer functions with respect to harmonic ground motion confirms the adopted choice. 1. Introduction

In the last two decades increasing attention on the mitigation of seismic or wind induced vibrations in adjacent structures through their “smart” coupling has been paid. A series of studies has been devoted to optimize the dynamic performance of slender structures, such as skyscraper or tall buildings, introducing dissipation systems acting on the relative motion in order to reduce the maximum displacements at the higher floors. Different applications of similar concepts have been applied in the retrofitting of existing adjacent structures. The seismic joints have been used to locate coupling devices able to dissipate me-chanical energy, and simultaneously avoid hammering phenomena [1]. In all cases “smart” coupling between adjacent structures has been exploited using passive, semi-active, and active control system with different features and performances.

Focusing the attention on the passive coupling of adjacent struc-tures, different modelling approaches have been proposed. The syn-thetic description of the main problem features through a pair of sim-ple oscillators interconnected by means of a springs and dashpot in se-


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1 Department of Structures, Geotechnics, Engineering Geology, University of Basi-licata, Potenza, Italy.

2 IMAA-CNR, Tito Scalo (PZ), Italy.

181

Damage level vs fundamental frequencies of damaged RC buildings

Rocco Ditommaso 1, Maria Rosaria Gallipoli 2, Marco Mucciarelli 1, Marco Vona 1

Abstract The determination of the fundamental period of Reinforced Con-crete (RC) buildings is an important topic for the modern earthquake engineering. This article provides the preliminary results of a wide survey on dynamic characteristic of existing RC buildings, damaged by the April 6th 2009 L’Aquila earthquake. For the first time in Italy, the fundamental periods of a set of RC buildings have been identified after a strong seismic sequence. Within the epicentral area, about 50 buildings with several built typology, structural characteristics, age and heights have been investigated. Four different damage levels were considered with regard to the 5 damage levels defined by EMS 98 (European Macroseismic Scale). In order to obtain the distribution of fundamental periods as a function of building height and damage level preliminary elaborations have been carried out. The fundamental pe-riod of RC damaged buildings, for low damage level, is close to val-ues estimated in previous studies relevant to undamaged buildings. When damage levels get higher, the fundamental periods show, as ex-pected, a general increase but reaching values lower than those pro-vided by recent building codes.


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1 University of l’Aquila, Italy.

189

Mechanical Behaviour of Non Structural ElementsDuring L'Aquila Earthquake

Antonello Salvatori 1

In L’Aquila, because of 2009 earthquake, R.C. buildings have shown a noticeable damage both to the external infill panels, internal brick masonry panels and to other non structural elements.

These kind of damage has been observed in most of the areas of the city and, generally, it reveals to be independent by age and typology of r.c. buildings.

It’s worth noticing that the damage on the non structural elements involved a great economic loss, sociological consequences and strong distress, because of a large part of the population (about half, i.e. more than 35,000 people) is still now homeless only due to the extensive damage on non structural elements, and not because of structural damages or structural faults and collapses.

Of coarse, the observed types of non structural elements damage revealed very different each other; therefore, they have been mainly related to wrong construction techniques, and, in second order, to wrong non structural design.

The non structural damage caused many buildings being unusable, and so the relevant repair amount (and consequent seismic assess-ment) and the inconveniences for inhabitants have been greatly ampli-fied. In more recent buildings, where the infill panels were well built (by using steel connectors between structure and infill panels and veri-fying the out of plane collapse condition) the damages were generally totally or almost absent. In these cases the interaction between struc-tural and non structural elements has been highlighted.

In Italy (and in L’Aquila town) the types of infill are strongly dif-ferent and they vary according to age and technology of construction.

In the ‘30s – ‘40s buildings infill were made of a single layer, often composed by heavy brick masonry or, sometimes, by stone masonry.


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1 Laboratori Nazionali del Gran Sasso - INFN, S.S 17 Bis Km 18+910, 67010 As-sergi (L’Aquila), Italy

2 Dipartimento di Fisica "E. R. Caianiello", Università degli Studi di Salerno, Via Ponte don Melillo, 84084, Fisciano (SA), Italy

3 Dipartimento di Ingegneria delle Strutture, delle Acque e del Terreno, Università dell’Aquila, Nucleo Industriale di Bazzano, 67100, Monticchio (L’Aquila), Italy

4 Dipartimento di Scienze Ambientali, Via Vetoio - Coppito 1, 67010, Coppito (L'Aquila), Italy

5 Dipartimento di Geotecnologie per l’Ambiente e il Territorio, Università “G. D’Annunzio” di Chieti-Pescara, Campus Universitario Madonna delle Piane, Via dei Vestini, 31, 66013, Chieti Scalo, Italy

6 Dipartimento di Scienze della Terra, Università “La Sapienza” di Roma, Piazzale A. Moro, 5, 00185, Roma, Italy

7 Dipartimento di Ingegneria delle Acque e Chimica, Politecnico di Bari, Via Ora-bona, 4, 70125, Bari, Italy

195

In-depth understanding of 2009 L'Aquila earthquake: the contribution of Gran Sasso physico-chemical

groundwater data Raffaele Adinolfi Falcone1, Antonella Amoruso2, Valentina Carucci3,

Luca Crescentini2, Antonella Falgiani1, Mauro Manetta3, Andrea Marchetti4, Marco Paolessi3, Barbara Parisse3, Marco Petitta6,

Sergio Rusi5, Donato Sciannamblo7, Michele Spizzico7, and Marco Tallini3

Abstract The Mw= 6.3 earthquake that struck L’Aquila on April 6 2009 (01:32 GMT) occurred at a depth of about 9 km on the SW-dipping active normal fault (Paganica fault) which crosses the Gran Sasso car-bonate aquifer. Co-seismic changes in water discharge from springs, clearly induced by the earthquake, were observed. Spot measurements of the main physico-chemical parameters of spring waters (T, pH, electrical conductivity, main ions and 222Rn) were thus carried out, in order to compare the data in the interseismic period (pre- and post-


219

AUTHORS INDEX

Raffaele Adinolfi Falcone 195 Dario Albarello 23, 137 Sara Amoroso 37 Antonella Amoruso 195 Riccardo Mario Azzara 123 Francesco Benedettini 75 Francesco Bergamaschi 123 Etienne Bertrand 123 Marcello Bianca 137 Paola Bordoni 123 Giacomo Buffarini 63 Fabrizio Cara 123 Valentina Carucci 195 Arrigo Caserta 89 Alfredo M. Ceci 167 Maurizio Cerone 89 Paolo Clemente 63 Rocco Cogliano 123 Luca Crescentini 195 Francesco Crisi 89 Giovanna Cultrera 123 Alberto Delladio 89 Adriano De Sortis 75 Giuseppe Di Giulio 123 Rocco Ditommaso 181 Mauro Dolce 109 Gino D’Ovidio 89 Anne-Marie Duval 123 Antonella Falgiani 195 Antonio Fodarella 123 Maria Rosaria Gallipoli 137, 181 Vincenzo Gattulli 167 Aladino Govoni 89 Marco Lepidi 167 Enrico Lunedei 23 Mauro Manetta 195 Andrea Marchetti 195

220

Diego Marchetti 37 Silvano Marchetti 37 Sandro Marcucci 123 Fabrizio Marra 89 Giuliano Milana 75, 123 Paola Monaco 37 Marco Mucciarelli 181 Yutaka Nakamura 9, 89, 153 Marco Paolessi 195 Barbara Parisse 195 Marco Petitta 195 Francesco Potenza 167 Stefania Pucillo 123 Julie Régnier 123 Gaetano Riccio 123 Antonio Rovelli 89 Sergio Rusi 195 Antonello Salvatori 189 Donato Sciannamblo 195 Michele Spizzico 195 Marco Tallini 195 Ferdinando Totani 37 Gianfranco Totani 37 Gianfranco Valente 89 Marco Vona 181

SCIENTIFIC–DISCIPLINARY AREAS

Area 01 – Mathematical and Computer Sciences

Area 02 – Physical Sciences

Area 03 – Chemical Sciences

Area 04 – Earth’s Sciences

Area 05 – Biological Sciences

Area 06 – Medical Sciences

Area 07 – Agricultural and Veterinary Sciences

Area 08 – Civil Engineering and Architecture

Area 09 – Industrial and Information Engineering

Area 10 – Antiquity, Philological–Literary and Historical–Artistic Sciences

Area 11 – Historical, Philosophical, Pedagogical and Psychological Sciences

Area 12 – Juridical Sciences

Area 13 – Economic and Statistical Sciences

Area 14 – Political and Social Sciences

Aracne Publishing’s publications are on

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Printed in February 2011by «ERMES. Servizi Editoriali Integrati S.r.l.»00040 Ariccia (RM) – via Quarto Negroni, 15for della «Aracne editrice S.r.l.» di Roma

A08322

The Dynamic Interaction of Soil and Structure

The phenomena arising from the dynamic interaction of soil and structure repre-sent a research field that encompasses a wide range of scientific sectors, all of whi-

ch are important in the definition of methodologies for analysis and design. This takeson particular significance in light of the tragic events connected to the earthquake inL’Aquila on 6th April 2009. This book gathers together the research and design propo-sals put forward by experts in the fields of hydraulics, geology, geothecnics, structu-ral and transportation engineering, geophysics, physics, archaeologists and architects.

Contributions of Raffaele Adinolfi Falcone, Dario Albarello, Sara Amoroso, Antonella Amoruso, Riccardo Mario Azzara,Francesco Benedettini, Francesco Bergamaschi, Etienne Bertrand, Marcello Bianca, Paola Bordoni, Giacomo Buffarini,Fabrizio Cara, Valentina Carucci, Arrigo Caserta, Alfredo Maria Ceci, Maurizio Cerone, Paolo Clemente, Rocco Cogliano,Luca Crescentini, Francesco Crisi, Giovanna Cultrera, Alberto Delladio, Adriano De Sortis, Giuseppe Di Giulio, RoccoDitommaso, Mauro Dolce, Gino D’Ovidio, Anne–Marie Duval, Antonella Falgiani, Antonio Fodarella, Maria RosariaGallipoli, Vincenzo Gattulli, Aladino Govoni, Marco Lepidi, Enrico Lunedei, Mauro Manetta, Andrea Marchetti, DiegoMarchetti, Silvano Marchetti, Sandro Marcucci, Fabrizio Marra, Giuliano Milana, Paola Monaco, Marco Mucciarelli,Yutaka Nakamura, Marco Paolessi, Barbara Parisse, Marco Petitta, Francesco Potenza, Stefania Pucillo, Julie Régnier,Gaetano Riccio, Antonio Rovelli, Sergio Rusi, Antonello Salvatori, Donato Sciannamblo, Michele Spizzico, Marco Tallini,Ferdinando Totani, Gianfranco Totani, Gianfranco Valente, Marco Vona.

Gino D’Ovidio is Aggregate Professor of Transportation Engineering at the Univer-sity of L’Aquila. His research activity has concerned mainly non–conventional tran-

sport systems. His most significant scientific result is the technology definition and rea-lization of UAQ4 magnetic levitating train with resistance free to motion, except ae-rodynamic drag. He is author of more than 70 articles and several patents.

Yutaka Nakamura is President of System and Data Research and Visiting Professor ofTokyo Institute of Technology. His research activity concerns mainly EEW and vul-

nerability assessment for structures and ground. His developing systems are the first ac-tual EEW system UrEDAS, Compact UrEDAS, FREQL and AcCo, and his developing te-chniques are H/V spectral ratio and K–value methods.

Antonio Rovelli is Director of Research at INGV, Department of Seismology and Tec-tonophysics. His interest fields are strong–motion seismology and models of ground

shaking. He is author of more than 70 papers on ISI journals.

Gianfranco Valente is Professor of Structural Engineering at L’Aquila University. Hisresearch activity concerns mainly non–linear analysis, for geometry and materials,

static and dynamic. He is author of about 100 papers.

AR

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euro 20,00

ISBN 978-88-548-3693-x

COVERBY:STUDIO

BG

TheDynam

icInteraction

ofSoiland

Structureedited

byG.D’Ovidio,Y.N

akamura,A

.Rovellli,G.Valente



AND STRUCTURE



Gianfranco Valente

UNIVERSITÀ DEGLI STUDI DI L’AQUILADipartimento di Ingegneria delle Stuturedelle Acque e del Terreno

copertina New.qxp:A 170 mastro copertine 3-03-2011 10:35 Pagina 1

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