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  • Geological structures evaluated by means of scattering noise in ground penetrating radar images

     Santos Assunçao, Sonia Alexandra; Salinas Naval, Victor; Perez Gracia, Maria de La Vega; Caselles Magallon, Jose Oriol; Clapes Boixader, Jaime; Pujades Beneit, Luis Gonzaga; Gonzalez Drigo, Jose Ramon; Lantada Zarzosa, Nieves
    International Conference on Ground Penetrating Radar
    p. 255-261
    Presentation's date: 2014-07-02
    Presentation of work at congresses

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    Coastal geology in Barcelona City is formed by Quaternary sediments overlying Tertiary strata. The Quaternary plane is crossed by paleochannels and streams, all of them under the city structures and constructions. Boreholes demonstrate differences in the grain size distribution of the materials from the different geological structures. In this work, Ground-penetrating radar was proved as a tool to obtain quick information about these changes. The results from more than 20 km of GPR profiles in Barcelona city, seems to indicate that, depending on the relationship between the wavelength and grain size, GPR signal scattering increases significantly. Therefore, the analysis of the noise in GPR signals supplies information to determine the possible existence of geological changes in the quaternary deposits. Several tests and measures in well-known emplacements, as well as models and simulations, were used to determine the ability of this method in the study of the Barcelona plain shallow geology. Correlation between paleochannels and infilled streams and higher scattering noise is observed in this study. The analysis of the scattering effect on the amplitude of the radar data could help to locate paleochannels and subterranean infilled streams, being a valuable tool to improve the knowledge of the city subsoil.

  • Capacity, fragility and damage in reinforced concrete buildings: a probabilistic approach

     Vargas Alzate, Yeudy Felipe; Pujades Beneit, Luis Gonzaga; Barbat Barbat, Horia Alejandro; Hurtado Gómez, Jorge Eduardo
    Bulletin of earthquake engineering
    Vol. 11, num. 6, p. 2007-2032
    DOI: 10.1007/s10518-013-9468-x
    Date of publication: 2013-12
    Journal article

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    The main goals of this article are to analyze the use of simplified deterministic nonlinear static procedures for assessing the seismic response of buildings and to evaluate the influence that the uncertainties in the mechanical properties of the materials and in the features of the seismic actions have in the uncertainties of the structural response. A reinforced concrete building is used as a guiding case study. In the calculation of the expected spectral displacement, deterministic nonlinear static methods are simple and straightforward. For not severe earthquakes these approaches lead to somewhat conservative but adequate results when compared to more sophisticated procedures involving nonlinear dynamic analyses. Concerning the probabilistic assessment, the strength properties of the materials, concrete and steel, and the seismic action are considered as random variables. The Monte Carlo method is then used to analyze the structural response of the building. The obtained results show that significant uncertainties are expected; uncertainties in the structural response increase with the severity of the seismic actions. The major influence in the randomness of the structural response comes from the randomness of the seismic action. A useful example for selected earthquake scenarios is used to illustrate the applicability of the probabilistic approach for assessing expected damage and risk. An important conclusion of this work is the need of broaching the fragility of the buildings and expected damage assessment issues from a probabilistic perspective.

  • Comparison of seismometer and radar measurements for the modal identification of civil engineering structures

     Negulescu, Caterina; Luzi, G.; Crosetto ,, Michele; Raucoules, Daniel; Roullé, Agathe; Monfort, Daniel; Pujades Beneit, Luis Gonzaga; Colas, Bastien; Dewez, Thomas
    Engineering structures
    Vol. 51, p. 10-22
    DOI: 10.1016/j.engstruct.2013.01.005
    Date of publication: 2013-06
    Journal article

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    The vulnerability of structures subjected to dynamic actions has been a very active field of research in recent years. In particular, the use of ambient response recording aims to improve our knowledge about the dynamic behaviour of structures, and the interferometric Real Aperture Radar (RAR) technique has recently emerged as a promising tool for the identification of modal properties such as natural frequencies and mode shapes through ambient vibration measurements of structures. To evaluate the modal characteristics of a reinforced concrete wall building, measurements of ambient vibrations of the building were carried out using a RAR and a network of velocimeters...

  • Methodology and applications for the benefit cost analysis of the seismic risk reduction in building portfolios at broadscale

     Valcarcel Torres, Jairo Andrés; Mora Cuevas, Miguel; Cardona Arboleda, Omar Dario; Pujades Beneit, Luis Gonzaga; Barbat Barbat, Horia Alejandro; Bernal Granados, Gabriel Andres
    Natural hazards
    Vol. 69, num. 1, p. 845-868
    DOI: 10.1007/s11069-013-0739-2
    Date of publication: 2013-10-01
    Journal article

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    This article presents a methodology for an estimate of the benefit cost ratio of the seismic risk reduction in buildings portfolio at broadscale, for a world region, allowing comparing the results obtained for the countries belonging to that region. This methodology encompasses (1) the generation of a set of random seismic events and the evaluation of the spectral accelerations at the buildings location; (2) the estimation of the buildings built area, the economic value, as well as the classification in structural typologies; (3) the development of vulnerability curves for each typology; (4) the estimation of the annual average loss of the buildings portfolio in the current conditions as well as in the case of a hypothetical structural intervention. The benefit cost ratio is estimated as the difference between the estimates of the present value of these two annual average losses, divided by the retrofitting costs. This methodology has been applied to the portfolio of public schools of 14 countries of Latin America and the Caribbean, for evaluating the feasibility of the seismic risk reduction at a national scale. © 2013 Springer Science+Business Media Dordrecht.

  • Probabilistic assessment of the capacity, fragility and seismic damage of reinforced concrete buildings

     Vargas Alzate, Yeudy Felipe; Pujades Beneit, Luis Gonzaga; Barbat Barbat, Horia Alejandro; Hurtado Gómez, Jorge Eduardo
    Revista internacional de métodos numéricos para cálculo y diseño en ingeniería
    Vol. 29, num. 2, p. 63-78
    DOI: 10.1016/j.rimni.2013.04.003
    Date of publication: 2013-04
    Journal article

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    Currently, many structures existing in seismic areas are highly vulnerable because they have been built without the use of seismic design codes or by using outdated codes. Often, methods for assessing the vulnerability of the structures do not take into account that their seismic behavior is dynamic and highly nonlinear and, moreover, that the structural characteristics and action have large uncertainties. This article aims to assess the vulnerability of structures taking into account that the mechanical properties of materials and the seismic action are random variables, by using advanced techniques based on the Monte Carlo method and on the nonlinear stochastic dynamics. The results obtained with these techniques are compared with those corresponding to a standard vulnerability assessment, based on deterministic models, in order to highlight the differences between both approaches. The main conclusion of this work is the need to address the vulnerability assessment problem from a probabilistic perspective which, combined with advanced nonlinear static and dynamic structural analysis techniques, provides a powerful tool giving information impossible to be captured by means of deterministic models. Finally, detailed results obtained for a building with waffle slabs, which is a structural typology widely used in Spain, are included and discussed. Actualmente en las zonas sísmicas existen estructuras altamente vulnerables, puesto que han sido construidas sin seguir las especificaciones de normas de diseño sismorresistente o siguiendo normas obsoletas. Muchas veces los métodos para evaluar la vulnerabilidad de las estructuras no tienen en cuenta que su comportamiento sísmico es dinámico y fuertemente no lineal y que, además, las características estructurales y de la acción tienen grandes incertidumbres. En este artículo se propone evaluar la vulnerabilidad de las estructuras, considerando que las propiedades mecánicas de los materiales y la acción sísmica son variables aleatorias, mediante técnicas avanzadas con base en el método de Monte Carlo y en la dinámica estocástica no lineal. Los resultados obtenidos con estas técnicas se comparan con los correspondientes a una evaluación de vulnerabilidad estándar, que utiliza modelos deterministas, a fin de resaltar las diferencias entre los 2 enfoques. La principal conclusión de este trabajo es que existe una necesidad de abordar el problema de la evaluación de la vulnerabilidad de estructuras desde una perspectiva probabilista que, al ser combinada con técnicas avanzadas de análisis del comportamiento estructural no lineal estático y dinámico, proporciona una poderosa herramienta que permite obtener información imposible de conseguir mediante modelos deterministas. Se incluyen resultados detallados obtenidos sobre un edificio con forjados reticulares, que es una tipología estructural muy utilizada en España.

  • Probabilistic seismic risk evaluation of reinforced concrete buildings

     Vargas Alzate, Yeudi Felipe; Barbat Barbat, Horia Alejandro; Pujades Beneit, Luis Gonzaga; Hurtado Gómez, Jorge Eduardo
    Proceedings of the Institution of Civil Engineers: Structures and Buildings
    Vol. 167, num. 6, p. 327-336
    DOI: 10.1680/stbu.12.00031
    Date of publication: 2013-09
    Journal article

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    The main objective of this article is to propose a simplified methodology to assess the expected seismic damage in reinforced concrete buildings from a probabilistic point of view by using Monte Carlo simulation. In order to do so, the seismic behaviour of the building was studied by using random capacity obtained by considering the mechanical properties of the materials as random variables. From the capacity curves, the damage states and fragility curves can be obtained, and curves describing the expected seismic damage to the structure as a function of a seismic hazard characteristic can be developed. The latter can be calculated using the capacity spectrum and the demand spectrum according to the methodology proposed by the Risk-UE project. In order to define the seismic demand as a random variable, a set of real accelerograms were obtained from European and Spanish databases in such a way that the mean of their elastic response spectra was similar to an elastic response spectrum selected from Eurocode 8. In order to combine the uncertainties associated with the seismic action and the mechanical properties of materials, two procedures are considered to obtain functions relating the peak ground acceleration to the maximum spectral displacements. The first method is based on a series of non-linear dynamic analyses, while the second is based on the well-known ATC-40 procedure called equal displacement approximation. After applying both procedures, the probability density functions of the maximum displacement at the roof of the building are gathered and compared. The expected structural damage is finally obtained by replacing the spectral displacement calculated using ATC-40 and the incremental dynamic procedure. In the damage functions, the results obtained from incremental static and dynamic analyses are compared and discussed from a probabilistic point of view.

  • Deterministic and probabilistic earthquake scenarios for the seismic risk analysis of URM buildings

     Avila Haro, Jorge Arturo; Gonzalez Drigo, Jose Ramon; Vargas Alzate, Yeudy Felipe; Pujades Beneit, Luis Gonzaga; Barbat Barbat, Horia Alejandro
    Key engineering materials
    Vol. 525-526, p. 537-540
    DOI: 10.4028/www.scientific.net/KEM.525-526.537
    Date of publication: 2013-05-02
    Journal article

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    Barcelona, as well as a large number of cities in the Mediterranean basin, has a housing stock composed of a large number of unreinforced brick masonry buildings. Motivated by different factors, the enlargement of the city (Eixample in Catalan) was held from the second half of the 19th century and the beginning of the 20th, a period in which a large number of buildings of this type were built, many of which are still used as dwellings. Although the buildings were built individually, some of them are linked to adjacent buildings by the side walls. This feature leads to the analysis of the buildings as isolated structures and also as an aggregate. Barcelona is located in a seismic region of low to moderate hazard, with macroseismic intensity between the grades VI and VII of the European macroseismic scale EMS'98. Based on the deterministic and probabilistic response spectra for the different types of soils present in Barcelona obtained in the work of Irizarry (2004), the seismic risk of four individual buildings and an aggregate is evaluated. The buildings are modeled and analyzed using the TREMURI program and MATLAB routines under the guidance of RISK-UE project.

  • Incremental dynamic analysis and pushover analysis of buildings: a probabilistic comparison

     Vargas Alzate, Yeudy Felipe; Pujades Beneit, Luis Gonzaga; Barbat Barbat, Horia Alejandro; Hurtado Gómez, Jorge Eduardo
    DOI: 10.1007/978-94-007-5134-7
    Date of publication: 2013-03-05
    Book chapter

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    The considerable influence of inherent uncertainties on structural behavior has led the engineering community to recognize the importance of a stochastic approach to structural problems. Issues related to uncertainty quantification and its influence on the reliability of the computational models are continuously gaining in significance. In particular, the problems of dynamic response analysis and reliability assessment of structures with uncertain system and excitation parameters have been the subject of continuous research over the last two decades as a result of the increasing availability of powerful computing resources and technology. This book is a follow up of a previous book with the same subject (ISBN 978-90-481-9986-0) and focuses on advanced computational methods and software tools which can highly assist in tackling complex problems in stochastic dynamic/seismic analysis and design of structures. The selected chapters are authored by some of the most active scholars in their respective areas and represent some of the most recent developments in this field. The book consists of 21 chapters which can be grouped into several thematic topics including dynamic analysis of stochastic systems, reliability-based design, structural control and health monitoring, model updating, system identification, wave propagation in random media, seismic fragility analysis and damage assessment. This edited book is primarily intended for researchers and post-graduate students who are familiar with the fundamentals and wish to study or to advance the state of the art on a particular topic in the field of computational stochastic structural dynamics. Nevertheless, practicing engineers could benefit as well from it as most code provisions tend to incorporate probabilistic concepts in the analysis and design of structures.

  • COST Action TU 1208 Civil Engineering Applications of Ground Penetrating Radar

     Pajewski, Lara; Pujades Beneit, Luis Gonzaga; Caselles Magallon, Jose Oriol; García, Alfredo; Salinas Naval, Victor; Lorenzo, Henrique; Perez Gracia, Maria de La Vega; Santos Assunçao, Sonia Alexandra; Solla, Mercedes; Clapes Boixader, Jaime; Trincks, Immo; Canas Torres, Jose Antonio; Neubauer, Wolfgang; VAN MEIRVENNE, Marc; Lambot, Sebastien; CRAEYE, Cristophe; MARCIC, Danijela; Bazic, Mario; LIBRIC, Lovorka; POLJAK, Dragan; RINGGAARD, Jorgen; BALAYSSAC, Jean-Paul; DEROBERT, Xavier; PICHOT DU MEZERAY, Christian; KIND, Thomas; TRELA, Christiane; STRYK, Josef; MATULA, Radek; PELLINEN, Terhi; WISEN, Roger; POPOVSKI, Borislav; LATKOSKI, Pero; KOPP, Christian; LOIZOS, Andreas; PLATI, Christina; MANACORDA, Guido; MASSA, Andrea; BENEDETTO, Andrea; FREZZA, Fabrizio; KUTEVS, Valerijs; D'AMICO, Sebastiano
    Competitive project

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  • Análisis estructural estático y dinámico probabilista de edificios de hormigón armado. Aspectos metodológicos y aplicaciones a la evaluación del daño.  Open access

     Vargas Alzate, Yeudy Felipe
    Universitat Politècnica de Catalunya
    Theses

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    Esta tesis propone una metodología de evaluación del daño sísmico basada en el método del espectro de capacidad pero con un enfoque probabilista que se apoya en simulaciones Monte Carlo. Así la acción sísmica, la estructura y el daño esperado se consideran y se analizan como variables aleatorias. La metodología, que se valida mediante el análisis dinámico incremental, es una nueva, robusta y potente herramienta de análisis de riesgo tanto a nivel de edificios individuales como a nivel urbano y regional. La validación mediante el análisis dinámico, de hecho, ha supuesto crear también una metodología probabilista basada en el análisis dinámico incremental. El daño esperado puede obtenerse para cualquier intervalo de confianza permitiendo así, a los gestores de la protección civil la elección de los niveles prioritarios o de interés. Como el análisis dinámico incremental requiere acelerogramas, se ha optado por usar registros de terremotos y se ha diseñado una técnica que, para una determinada base de datos, permite optimizar, minimizando la dispersión, el número de acelerogramas compatibles con un determinado espectro de respuesta; de esta forma la incertidumbre en la acción sísmica se considera de una manera adecuada. Aunque a efectos metodológicos, se ha estimado suficiente y adecuado considerar como variables aleatorias gaussianas sólo las propiedades resistentes del hormigón y el acero, con todo se ha introducido también una nueva e interesante forma de incorporar la variabilidad espacial de la resistencia de vigas y columnas. Los desarrollos metodológicos se ilustran con numerosos casos de estudio de edificios existentes y bien documentados. En particular, se han estudiado los edificios de hormigón armado con forjados reticulares, clasificados en altos, de altura mediana y bajos. Este estudio se ha realizado considerando acciones sísmicas compatibles con los espectros previstos en el eurocódigo EC8 para terremotos tipo 1 y tipo 2 y para suelos A, B, C, D y E. La aplicación del método a edificios irregulares ha confirmado la insuficiencia de los modelos 2D para estructuras asimétricas. Así, el método probabilista se ha aplicado a dos edificios de especial importancia para escenarios sísmicos de interés. El primero es el hospital de Vielha, para la acción sísmica con un periodo de retorno de 475 años; el segundo es un edificio del Barrio de San Fernando en Lorca, que fue severamente dañado por el terremoto del mes de mayo de 2011. En este segundo caso la acción sísmica se ha definido de forma determinista mediante las dos componentes horizontales de aceleración registradas en la ciudad. En los análisis 3D se ha incorporado el efecto de direccionalidad, concluyendo que edificios del mismo tipo situados en un mismo lugar pueden sufrir daños significativamente distintos dependiendo sólo de su orientación azimutal. Los resultados obtenidos en el caso de Lorca son compatibles con los daños observados lo que contribuye a validar el método probabilista y los desarrollos implementados en esta tesis.

    Esta tesis propone una metodología de evaluación del daño sísmico basada en el método del espectro de capacidad pero con un enfoque probabilista que se apoya en simulaciones Monte Carlo. Así la acción sísmica, la estructura y el daño esperado se consideran y se analizan como variables aleatorias. La metodología, que se valida mediante el análisis dinámico incremental, es una nueva, robusta y potente herramienta de análisis de riesgo tanto a nivel de edificios individuales como a nivel urbano y regional. La validación mediante el análisis dinámico, de hecho, ha supuesto crear también una metodología probabilista basada en el análisis dinámico incremental. El daño esperado puede obtenerse para cualquier intervalo de confianza permitiendo así, a los gestores de la protección civil la elección de los niveles prioritarios o de interés. Como el análisis dinámico incremental requiere acelerogramas, se ha optado por usar registros de terremotos y se ha diseñado una técnica que, para una determinada base de datos, permite optimizar, minimizando la dispersión, el número de acelerogramas compatibles con un determinado espectro de respuesta; de esta forma la incertidumbre en la acción sísmica se considera de una manera adecuada. Aunque a efectos metodológicos, se ha estimado suficiente y adecuado considerar como variables aleatorias gaussianas sólo las propiedades resistentes del hormigón y el acero, con todo se ha introducido también una nueva e interesante forma de incorporar la variabilidad espacial de la resistencia de vigas y columnas. Los desarrollos metodológicos se ilustran con numerosos casos de estudio de edificios existentes y bien documentados. En particular, se han estudiado los edificios de hormigón armado con forjados reticulares, clasificados en altos, de altura mediana y bajos. Este estudio se ha realizado considerando acciones sísmicas compatibles con los espectros previstos en el eurocódigo EC8 para terremotos tipo 1 y tipo 2 y para suelos A, B, C, D y E. La aplicación del método a edificios irregulares ha confirmado la insuficiencia de modelos 2D en estructuras asimétricas. Así, el método probabilista se ha aplicado a dos edificios de especial importancia para escenarios sísmicos de interés. El primero es el hospital de Vielha, para la acción sísmica con un periodo de retorno de 475 años; el segundo es un edificio del Barrio de San Fernando en Lorca, que fue severamente dañado por el terremoto del mes de mayo de 2011. En este segundo caso la acción sísmica se ha definido de forma determinista mediante las dos componentes horizontales de aceleración registradas en la ciudad. En los análisis 3D se ha incorporado el efecto de direccionalidad, concluyendo que edificios del mismo tipo situados en un mismo lugar pueden sufrir daños significativamente distintos dependiendo sólo de su orientación azimutal. Los resultados obtenidos en el caso de Lorca son compatibles con los daños observados lo que contribuye a validar el método probabilista y los desarrollos implementados en esta tesis.

    This dissertation proposes a methodology for seismic damage assessment based on the capacity spectrum method but with a probabilistic approach which is supported on Monte Carlo simulation. The seismic action, the structure and the expected damage are considered and analyzed as random variables. The method, which is validated through incremental dynamic analysis, is a new, robust and powerful tool for risk analysis that can be applied to individual buildings, but also at urban and regional scales. In fact, the validation through dynamic analyses has involved creating also a probabilistic method for damage assessment, based on incremental dynamic analysis. The expected damage can be obtained for any confidence interval thus allowing the civil protection managers choosing the levels of priority or interest. As incremental dynamic analyses require accelerograms, the use of earthquake records has been preferred and it has been developed a specific technique that, for a given database, minimizes the dispersion and optimizes the number of accelerograms compatible with a given response spectrum; in this way, the uncertainties in the seismic action are considered in an appropriate manner. Although for methodological purposes it was estimated sufficient and adequate to consider only the strength properties of concrete and steel as Gaussian random variables, yet a new and interesting way to incorporate the spatial variability of the strength of beams and columns has been also proposed. The methodological developments are illustrated with numerous case studies of existing and well documented buildings. Specifically, reinforced concrete buildings with waffle slabs, classified as low-rise, mid-rise and high-rise, have been studied. This study has been conducted considering seismic actions compatible with the response spectra foreseen in the Eurocode EC8 for type 1 and type 2 earthquakes and soil classes A, B, C, D and E. The application of the method to irregular buildings confirmed the insufficiency of 2D models for asymmetric structures. Thus, the probabilistic method has been applied to two buildings of special importance for seismic scenarios of interest. The first one is the hospital of Vielha considering the seismic action with a return period of 475 years; the second one is a building located in the neighborhood of San Fernando in Lorca, which was severely damaged by the earthquake of May 2011. In this second case the seismic action has been defined deterministically by means of the two horizontal accelerograms recorded in the city. In 3D analyses the directionality effect is considered, concluding that buildings of the same type located in the same place can suffer significantly different damages depending only of their azimuthal angle. The results obtained in the case of Lorca are compatible with the observed damage. This fact supports the validity of the probabilistic method as well as that of the developments implemented in this thesis.

  • Análisis y gestión del riesgo sísmico de edificios y sistemas esenciales  Open access

     Valcarcel Torres, Jairo Andres
    Department of Strength of Materials and Structural Engineering, Universitat Politècnica de Catalunya
    Theses

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    En este trabajo se adoptan y presentan metodologias para evaluar Ia seguridad y riesgo sismica, asi como Ia factibilidad delas actividades de reducci6n de perdidas, con elfin de priorizar estudios detallados y orientar program as de reducci6n de Iavulnerabilidad sismica de edificios ysistemas esenciales. Estes procedimientos se aplican en diferentes casas de estudio,a escala local, regional, nacional ysupranacional, realizando evaluaciones sabre centres educativos ycentros de salud,entre otros edificios de importancia especial.Respecto a Ia evaluaci6n de Ia seguridad sismica, se adopta un metoda simplificado basado en espectros de capacidadpara evaluar el comportamiento ycalificar su seguridad de acuerdo a los estandares propuestos par el Comite VISION2000. Para este analisis, los edificios se clasifican en tipologias estructurales para las cuales se conocen espectros decapacidad. Para estimar Ia acci6n sismica (en roca firm e), se adaptan espectros de amenaza uniforme a las form asespectrales del Euroc6digo 8. Para evaluar Ia acci6n sismica en superficie, se emplean espectros de respuesta paradiferentes tipos de suelo, de acuerdo a los resultados de estudios de mesozonaci6n sismica. A partir de Ia evaluaci6n delcomportamiento ydano esperado de los edificios, se presentan alternativas para evaluar las perdidas econ6micas, indicesde funcionalidad, asi como estimaciones del tiempo de recuperaci6n que permiten identificar las instalaciones mas criticas.Los analisis de seguridad sismica se realizaron a escala local, a edificios esenciales de municipios de Val d'Aran (Espana)asi como a nivel regional, para un conjunto de centres educativos yde hospitales de Cataluna (Espana), considerandoescenarios de periodo de retorno de 475 y975 anos.Respecto al analisis del riesgo sismica, en este trabajo se adoptan metodologias para Ia estimaci6n de perdidasesperadas ante un conjunto de eventos potencialmente daninos, descritos par su magnitud ytasa de recurrencia. Dichoseventos se generan de acuerdo a Ia sismicidad de Ia zona de estudio. Para cada evento se evaluan las aceleracionesespectrales correspondientes allugar donde se hallan las instalaciones empleando I eyes de atenuaci6n. Los edificios seclasifican en tipologias estructurales para las cuales se desarrollan curvas de dana yde perdida esperada en terminos deIa aceleraci6n espectral. Baja este anal isis es posible estimar Ia perdida maxima probable para eventos de diferentesperiodos de retorno, asi como Ia perdida anual esperada. Esta metodologia se aplica a escalas nacional y supranacionalpara evaluar relaciones de beneficia-costa de Ia reducci6n del riesgo sismica de centres educativos publicos de paises deAmerica Latina.Como complemento a los analisis de perdidas dire~s, se presentan metodologias para evaluar las perdidas asociadas aIa interrupci6n del servicio de edificios esenciales durante terremotos, asi como los impactos del desastre. En el caso de Iainfraestructura sanitaria, se desarrolla un modele para evaluar Ia respuesta de una red de hospitales ante un con junto deeventos sismicos. Para cad a uno se estiman el numero de pacientes ingresados, en espera y no tratados oportunamente.Asu vez, se adopta una metodologia para estimar Ia reducci6n esperada en Ia atenci6n a Ia salud de Ia poblaci6n, dadoslos danos estimados en los hospitales en escenarios de periodo de retorno de 475 y975 anos. Estas metodologias seaplican a los hospitales publicos de Cataluna.Las metodologias propuestas y los resultados obtenidos son utiles para evaluar Ia importancia de Ia seguridad sismica delos edificios y sistemas esenciales. Adem as de Ia verificaci6n de los estandares de seguridad, los indices de perdidaecon6mica, de funcionalidad, el analisis de respuesta ante emergencias y los impactos del desastre perm iten identificar losbeneficios de Ia reducci6n de Ia fragilidad de las instalaciones, dando soporte a program as de mitigaci6n del riesgo.

    Los daños por terremotos en edificios y sistemas esenciales han motivado la definición de estándares de comportamiento de estas instalaciones, buscando reducir las pérdidas económicas y la pérdida de funcionalidad. Varias iniciativas nacionales y regionales han sugerido procedimientos para la evaluación del comportamiento y fragilidad de los edificios. Estos avances han dado soporte para la gestión de programas nacionales y regionales para la reducción de la vulnerabilidad de instalaciones esenciales, en los cuales se debe decidir entre ejecutar obras de reforzamiento o bien, renovar la infraestructura. En este trabajo se adoptan y presentan metodologías para evaluar la seguridad y riesgo sísmico, así como la factibilidad de las actividades de reducción de pérdidas, con el fin de priorizar el análisis detallado y orientar programas de reducción de la vulnerabilidad sísmica de edificios y sistemas esenciales. Estos procedimientos se aplican en diferentes casos de estudio, a escala local, regional, nacional y supranacional, realizando evaluaciones sobre centros educativos y centros de salud, entre otros edificios de importancia especial. Respecto a la evaluación de la seguridad sísmica de los edificios esenciales, se adopta un método simplificado basado en espectros de capacidad, propuesto en el proyecto RISK UE para evaluar su comportamiento y calificar su seguridad de acuerdo a los estándares sugeridos por el Comité VISION 2000. Para este análisis, los edificios se clasifican en tipologías estructurales para las cuales se conocen espectros de capacidad. Para estimar la acción sísmica (en roca firme), se adaptan espectros de amenaza uniforme a las formas espectrales del Eurocódigo 8. Para evaluar la acción sísmica en superficie, se emplean espectros de respuesta para diferentes tipos de suelo, de acuerdo a los resultados de estudios de mesozonación sísmica. A partir de la evaluación del comportamiento y daño esperado de los edificios, se presentan alternativas para evaluar las pérdidas económicas, índices de funcionalidad, así como estimaciones del tiempo de recuperación, que permiten identificar las instalaciones más críticas. Estos procedimientos se aplican a edificios esenciales de Cataluña (España), considerando periodos de retorno de 475 y 975 años. A escala local, esta metodología se aplica a los edificios esenciales ubicados en la Comarca de Val d’Arán. Este análisis permite evaluar su seguridad y priorizarlos según los daños esperados. De estos resultados se encuentra que cerca del 70% de los edificios son operacionales para periodos de retorno de 475 años. Para periodos de retorno de 975 años, son menos del 10% los edificios no cumplen con el nivel de comportamiento de seguridad de la vida. En cuanto a los daños esperados, el promedio de las instalaciones, para un periodo de retorno de 475 años, tienen un índice de pérdida económica del 25%. En cuanto a su funcionalidad, se observa que cerca del 50% tienen un índice de funcionalidad menor a 0.5. A escala regional, el mismo procedimiento se aplica para evaluar la seguridad de un conjunto de centros educativos de Cataluña, compuesto por instalaciones ubicadas en la Comarca de Val d’Aran, en la Provincia de Girona, así como edificios construidos con sistemas industrializados, la mayoría situados en la Provincia de Barcelona. Del total de centros analizados, para un periodo de retorno de 475 años, son menos del 5% las instalaciones que no cumplen con el nivel de comportamiento operacional. Para un periodo de retorno de 975 años, todos los centros educativos cumplen con el requisito de seguridad de la vida. El promedio de la pérdida económica de los centros de Girona se encuentra entre el 15% y el 20%. El promedio de la pérdida económica del conjunto de edificios industrializados es inferior al 5%. Para los centros educativos de de Val d’Aran, el promedio de la pérdida económica es del 25%. En forma similar, se desarrolla una evaluación de la seguridad de un conjunto de hospitales públicos de Cataluña. Para eventos de periodo de retorno de 475 años, cerca del 16% no cumplen el nivel de comportamiento operacional. Para eventos de periodo de retorno de 975 años, todos los hospitales cumplen con el requisito de seguridad de la vida. Además de la evaluación del comportamiento, se estiman índices de pérdida económica, de funcionalidad y se propone un Índice de Vulnerabilidad de Hospitales que incluye aspectos estructurales, no estructurales y de capacidad de respuesta a emergencias. Como complemento a la verificación de estándares de seguridad, en este trabajo se adoptan metodologías para la estimación de pérdidas esperadas ante un conjunto de eventos potencialmente dañinos, descritos por su magnitud y tasa de recurrencia. Dichos eventos se generan de acuerdo a la sismicidad de la zona de estudio. Para cada evento se evalúan las aceleraciones espectrales correspondientes al lugar donde se hallan las instalaciones empleando leyes de atenuación. Los edificios se clasifican en tipologías estructurales para las cuales se desarrollan curvas de vulnerabilidad. Dichas curvas relacionan la pérdida esperada y su desviación estándar con la aceleración espectral. Bajo este análisis es posible estimar la pérdida máxima probable para eventos de diferentes periodos de retorno, así como la pérdida anual esperada. Esta metodología se aplica a escala supranacional para evaluar relaciones de beneficio-costo de la reducción del riesgo sísmico en el área construida de centros educativos públicos de países de América Latina. Este análisis se centra en las pérdidas económicas y permite identificar los países en los cuales resulta viable la intervención estructural. Estos resultados se comparan con índices de progreso del sector educativo y de inversión pública en educación, con el fin de identificar los países en los cuales, los daños en la infraestructura escolar representan altos costos de oportunidad y pueden afectar el cumplimiento de los objetivos y metas en educación. Para la gestión de la seguridad de los edificios y sistemas esenciales, además de la estimación de las pérdidas económicas, es de interés evaluar las pérdidas asociadas a la interrupción del servicio durante terremotos, así como los impactos del desastre. Para el primer caso, se desarrolla un modelo para evaluar la respuesta de los hospitales durante eventos sísmicos. En este modelo se estiman el número de pacientes ingresados, en espera y no tratados oportunamente en un conjunto de hospitales. Este análisis se desarrolla para el conjunto de hospitales públicos de Cataluña para periodos de retorno de 475 y 975 años, así como para un conjunto de eventos generados de acuerdo a la peligrosidad sísmica de la región de estudio. De este análisis se encuentra que los hospitales con comportamiento crítico son aquellos ubicados en las zonas de mayor densidad de población y de mayor peligrosidad sísmica, en las cuales se espera que ocurran más heridos y que los hospitales puedan tener mayores daños. Para periodos de retorno de 475 años, el porcentaje de heridos no tratados oportunamente en el sistema puede llegar a ser del 8% y del 25% para periodos de retorno de 975 años. Para evaluar el impacto socioeconómico de los daños por terremotos en edificios esenciales, en este trabajo se adoptan metodologías para estimar los efectos sobre la población asociados a la reducción del funcionamiento de las instalaciones luego de eventos sísmicos. Estos procedimientos se aplican a un conjunto de hospitales públicos de Cataluña, con el fin de evaluar la reducción en la producción de salud, teniendo en cuenta diferentes escenarios de daños. La producción de salud se considera como el resultado de los servicios médicos ofrecidos con la infraestructura y recursos hospitalarios disponibles, los cuales influyen en la salud de la población. La producción de salud se mide en términos de la tasa de mortalidad (número de personas fallecidas anualmente por cada mil habitantes). De esta manera, una reducción en la producción de salud está relacionada con aumentos en la tasa de mortalidad. En el modelo adoptado, la producción de salud se relaciona con indicadores de los recursos sanitarios como el número de camas, personal médico y el diagnóstico de pacientes empleando nuevas tecnologías. De los resultados de este análisis se encuentra que, para escenarios de periodo de retorno de 475, la reducción en la producción de salud está relacionada con incrementos en la tasa de mortalidad de 0.84 muertos por cada mil habitantes. Dicho incremento es de de 1.14 para periodos de retorno de 975 años. Las metodologías propuestas y los resultados obtenidos son útiles para evaluar la importancia de la seguridad sísmica de los edificios y sistemas esenciales. Además de la verificación de los estándares de seguridad, los índices de pérdida económica, de funcionalidad, el análisis de respuesta ante emergencias y los impactos luego del desastre permiten identificar los beneficios de la reducción de la fragilidad de las instalaciones, dando soporte a programas de mitigación del riesgo.

    In this thesis, several methods to evaluate the seismic safety and seismic risk of essential and special buildings and systems are developed and applied. Those procedures are applied to case studies. Concerning the safety analysis, the seismic action is defined by means of response spectra which are defined according to the spectral shapes proposed In Euro-code EC 08. The soils effects are taken into account using the results of a seismic mesozonation study; buildings are defined by means of their bilinear capacity spectra but they are grouped ac-cording to simplified structural typologies. The expected damage is then estimated by means of a capacity spec-trum based method. Finally, the buildings safety is evaluated comparing the expected damage grades and the levels of seismic performance proposed by the Vision 2000 Committee. In the proposed method expected economic losses, residual functionality and recovery time periods also can be estimated. The obtained results allow identifying the buildings with worse seismic performance and can be useful for prioritizing vulnerability and risk reduction measures. The seismic safety study has been applied at local and regional scales. At local scale the buildings of special importance in the municipalities of Val d¿Aran (Spain) has been analyzed; at regional scale the methods are applied to a set of schools and public hospitals of Catalonia (Spain). Moreover well-known methods for seismic risk assessment were used to estimate expected losses in essential facilities when they are exposed to a set of potential harmful seismic events, which are defined by their magnitudes and recurrence rates. Then stochastic techniques are used to generate a family of such events according to the seismicity of the region of interest. For each event and for each building, the spectral accelerations at the site of the building are estimated by using seismological models linking magnitudes and spectral amplitudes and attenuation laws. Then, for each building typology, curves relating the expected economic losses and the spectral acceleration are developed. The method also allows estimating the corresponding standard deviations. The method can be applied before and after of hypothetical measures for reducing the vulnerability and seismic risk. Therefore, on this basis it is possible to estimate annual average losses according to the seismic hazard of the studied region. This procedure has been applied, at national and supranational scale, to obtain appraisals of the benefit-cost ratios of seismic risk reduction actions in schools in countries of Latin America. An added value of this thesis comes from the methods for assessing also the expected indirect losses associated to the disruption of essential and special facilities during earthquakes, as well as those related to the socioeconomic impacts of the disaster. In this context, a model was developed that allows evaluating the whole performance of a hospital network during seismic events. The method is based on the assessment, for each event, of the numbers of inpatients, injured people in waiting list and injured people not receiving treatment opportunely. The method also allows obtaining quantitative estimates of the expected reduction in the assistance of the health of the population. The methods and techniques proposed and used in this thesis, as well as the results obtained in specific case stud-ies, are useful for evaluating the actual seismic safety of essential facilities. Besides, the verification of the levels of performance, the assessment of indices of economic losses and of residual functionality, the analysis of the response, capacity and resilience to face emergencies and the detailed study of the impacts of the disasters, allow identifying the benefits of activities oriented to the reduction of the seismic vulnerability and risk, even in low to moderate seismic hazard areas.

  • Seismic and structural response of a framed four level building with RC and steel structure designed according to current Venezuelan codes

     Ugel Garrido, Ronald David; Herrera González, Reyes Indira; Vielma Pérez, Juan Carlos; Barbat Barbat, Horia Alejandro; Pujades Beneit, Luis Gonzaga
    International Conference on Earthquake Resistant Engineering Structures
    p. 109-120
    Presentation's date: 2013-07
    Presentation of work at congresses

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    This study determines the structural behavior of a four level framed building with composite RC and steel structure designed according Venezuelan seismic codes. The structural system consists of RC frames in the first three levels and steel frames in the fourth. It was performed linear analysis to design all structural elements. Capacity curves and performance points were obtained with pushover analysis. Results showed greater ductility in the X frames¿ direction and greater resistance reserve in the external frames. Performing points showed adequate resistance values but low stiffness in two Y frames¿ directions. Seismic action is carried on through synthetic accelerograms defined by the seismic codes used in this study. Dynamic analysis is used to compute parameters of ductility, over strength and displacements. In one case the collapse Limit State was reached, implying a general collapse of the building. Incremental dynamic analysis was performed to obtain fragility curves and damage probability matrix; a very high probability of significant lateral displacement and damage was evidenced from this despite a normative design of structural elements.

    This study determines the structural behavior of a four level framed building with composite RC and steel structure designed according Venezuelan seismic codes. The structural system consists of RC frames in the first three levels and steel frames in the fourth. It was performed linear analysis to design all structural elements. Capacity curves and performance points were obtained with pushover analysis. Results showed greater ductility in the X frames’ direction and greater resistance reserve in the external frames. Performing points showed adequate resistance values but low stiffness in two Y frames’ directions. Seismic action is carried on through synthetic accelerograms defined by the seismic codes used in this study. Dynamic analysis is used to compute parameters of ductility, over strength and displacements. In one case the collapse Limit State was reached, implying a general collapse of the building. Incremental dynamic analysis was performed to obtain fragility curves and damage probability matrix; a very high probability of significant lateral displacement and damage was evidenced from this despite a normative design of structural elements.

  • Evaluación probabilista del riesgo sísmico de edificios de hormigón armado con base en la degradación de la rigidez

     Barbat Barbat, Horia Alejandro; Vargas Alzate, Yeudy Felipe; Pujades Beneit, Luis Gonzaga; Hurtado Gómez, Jorge Eduardo
    Congreso Nacional de Ingeniería Sísmica, Colombia
    p. 1-21
    Presentation's date: 2013-05-29
    Presentation of work at congresses

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    The incremental dynamic analysis is a powerful tool for evaluating the seismic vulnerability and risk of buildings. It allows calculating the global damage of structures for different peak ground accelerations, PGA, and representing this result by means of damage curves. Such curves are currently used to obtain seismic risk scenarios at urban level. Even if the application of this method in a probabilistic environment requires a relevant computational effort, it is the reference method for determining those curves. Nevertheless, it would be of high practical interest to have a simpler method based, for instance, on pushover analysis, for assessing the seismic vulnerability and risk of buildings, which allows obtaining results similar to those based on the incremental dynamic analysis. Referring to the capacity-spectrum-based-methods, expert opinions have been used in previous researches for defining damage states thresholds starting from the yielding and the ultimate spectral displacement identified in the bilinear capacity spectrum. But we prove in this article that the results provided by these methods do not reproduce with sufficient precision the dynamic ones. Therefore, a new procedure for defining the damage states thresholds, based on the stiffness degradation of reinforced concrete building, is proposed herein and a fully probabilistic approach is tackled by means of Monte Carlo simulations. It is demonstrated in the paper that the obtained results are in good agreement with those calculated using the incremental dynamic analysis.

    The incremental dynamic analysis is a powerful tool for evaluating the seismic vulnerability and risk of buildings. It allows calculating the global damage of structures for different peak ground accelerations, PGA, and representing this result by means of damage curves. Such curves are currently used to obtain seismic risk scenarios at urban level. Even if the application of this method in a probabilistic environment requires a relevant computational effort, it is the reference method for determining those curves. Nevertheless, it would be of high practical interest to have a simpler method based, for instance, on pushover analysis, for assessing the seismic vulnerability and risk of buildings, which allows obtaining results similar to those based on the incremental dynamic analysis. Referring to the capacity‐spectrum‐based‐methods, expert opinions have been used in previous researches for defining damage states thresholds starting from the yielding and the ultimate spectral displacement identified in the bilinear capacity spectrum. But we prove in this article that the results provided by these methods do not reproduce with sufficient precision the dynamic ones. Therefore, a new procedure for defining the damage states thresholds, based on the stiffness degradation of reinforced concrete building, is proposed herein and a fully probabilistic approach is tackled by means of Monte Carlo simulations. It is demonstrated in the paper that the obtained results are in good agreement with those calculated using the incremental dynamic analysis.

  • Risk assessment of reinforced concrete buildings considering the earthquake directionality effects

     Vargas Alzate, Yeudy Felipe; Pujades Beneit, Luis Gonzaga; Barbat Barbat, Horia Alejandro; Hurtado Gómez, Jorge Eduardo
    Computational Methods in Structural Dynamics and Earthquake Engineering
    p. 1-11
    Presentation's date: 2013-06-12
    Presentation of work at congresses

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    In order to assess the seismic risk of structures, several methods based on pushover analysis have been developed. These methods are very useful in the case of symmetric structures because they can be easily approximated by means of a 2D model. In the case of asymmetric structures several improvements to the pushover analysis procedure have been proposed for considering the effect of asymmetry on the global response. However, such methods, in some cases, can be more expensive, from computational point of view, than the nonlinear dynamic analysis. In this article, we propose to assess the effect of the directionality of the earthquake by using non-linear dynamic analysis and considering uncertainties in the mechanical properties of the materials and in the seismic action. We use as a case study a group of reinforced concrete buildings located in Lorca, Spain, damaged by the earthquake of May 2011. The results show a good agreement between the observed and the calculated damage.

    In order to assess the seismic risk of structures, several methods based on pushover analysis have been developed. These methods are very useful in the case of symmetric structures because they can be easily approximated by means of a 2D model. In the case of asym-metric structures several improvements to the pushover analysis procedure have been proposed for considering the effect of asymmetry on the global response. However, such methods, in some cases, can be more expensive, from computational point of view, than the nonlinear dynamic analysis. In this article, we propose to assess the effect of the directionali-ty of the earthquake by using non-linear dynamic analysis and considering uncertainties in the mechanical properties of the materials and in the seismic action. We use as a case study a group of reinforced concrete buildings located in Lorca, Spain, damaged by the earthquake of May 2011. The results show a good agreement between the observed and the calculated damage.

  • Análisis comparativo del peligro sísmico de Barcelona

     Aguilar Meléndez, Armando; Pujades Beneit, Luis Gonzaga; Ordaz Schroeder, Mario Gustavo; Barbat Barbat, Horia Alejandro; Lantada Zarzosa, Nieves; García Elías, Alejandro; Campos, Amelia
    Congreso Nacional de Ingeniería Sísmica
    p. 1-17
    Presentation's date: 2013-11-07
    Presentation of work at congresses

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  • Seismic response and torsional effects of RC structure with irregular plant and variations in diaphragms, designed with Venezuelan codes

     Herrera González, Reyes Indira; Vielma Pérez, Juan Carlos; Ugel Garrido, Ronald David; Barbat Barbat, Horia Alejandro; Pujades Beneit, Luis Gonzaga
    International Conference on Earthquake Resistant Engineering Structures
    p. 85-96
    Presentation's date: 2013-07
    Presentation of work at congresses

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    The objective of this study is to determine the seismic response and torsional effects of an existing Reinforced Concrete building with irregular plant and five levels projected according to an older version of Venezuelan seismic design code. Two structures were analysed: the original building and a redesigned version. Nonlinear static analysis and nonlinear 3D dynamic analysis were applied, based on registers of three synthetic accelerograms compatible with the elastic design spectrum for the used code. In 3D analysis, four structures were simulated, with and without rigid diaphragms so as to compare the seismic behaviour of the buildings. Through this nonlinear analysis parameters were determined that define the behaviour of the structure, torsional moments and rotations in columns reached for simulated buildings. Also, to obtain damage fragility curves for five states damage were generated. Results show that the original structure has an inadequate resistant behaviour and a high probability of exceeding the moderate damage state, while the redesigned structure presents good performance under seismic events according to the existing code. It was also observed that maximum torsional effects occur in the entrant corners of the irregular plant, which are reduced in mid-rise buildings by using a rigid diaphragm.

    The objective of this study is to determine the seismic response and torsional effects of an existing Reinforced Concrete building with irregular plant and five levels projected according to an older version of Venezuelan seismic design code. Two structures were analysed: the original building and a redesigned version. Nonlinear static analysis and nonlinear 3D dynamic analysis were applied, based on registers of three synthetic accelerograms compatible with the elastic design spectrum for the used code. In 3D analysis, four structures were simulated, with and without rigid diaphragms so as to compare the seismic behaviour of the buildings. Through this nonlinear analysis parameters were determined that define the behaviour of the structure, torsional moments and rotations in columns reached for simulated buildings. Also, to obtain damage fragility curves for five states damage were generated. Results show that the original structure has an inadequate resistant behaviour and a high probability of exceeding the moderate damage state, while the redesigned structure presents good performance under seismic events according to the existing code. It was also observed that maximum torsional effects occur in the entrant corners of the irregular plant, which are reduced in mid-rise buildings by using a rigid diaphragm.

  • Seismic performance of a block of buildings representative of the typical construction in the Eixample district in Barcelona (Spain)

     Pujades Beneit, Luis Gonzaga; Barbat Barbat, Horia Alejandro; Gonzalez Drigo, Jose Ramon; Avila Haro, Jorge Arturo; Lagomarsino, S.
    Bulletin of earthquake engineering
    Vol. 10, num. 1, p. 331-349
    DOI: 10.1007/s10518-010-9207-5
    Date of publication: 2012-02
    Journal article

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  • Nuevas Avances de la Geofísica y la Ingeniería aplicados a la evaluación del riesgo sísmico

     Lana Pons, Francisco Javier; Caselles Magallon, Jose Oriol; Perez Gracia, Maria de La Vega; Gonzalez Drigo, Jose Ramon; Martínez Santafé, Maria Dolors; Lopez Almansa, Francisco; Serra De Larrocha, Carina; Canas Torres, Jose Antonio; Pujades Beneit, Luis Gonzaga
    Competitive project

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  • UN NUEVO ENFOQUE DE LOS PRECURSORES SÍSMICOS: MONITORIZACIÓN DE LA INTERACCIÓN FRÁGIL-DÚCTIL DE LA LITOSFERA Y SU RELACIÓN CON GRANDES TERREMOTOS  Open access

     Tarela Alonso, Ester
    Department of Geotechnical Engineering and Geo-Sciences, Universitat Politècnica de Catalunya
    Theses

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    The main goal of this thesis is to test the brittle-ductile (BD) interaction hypothesis of the lithosphere. The model uses the correlation of two parameters, the seismicity characterizing the brittle part and the attenuation representing the ductile part. It assumes the coupling of both parts and therefore the correlation between the time series of the parameters during the normal part of the stress loading cycle. A few years before the occurrence of a major earthquake, the brittle part of the system suffers a stress overload, so it cannot maintain the normal loading processes through the brittle-ductile transition zone, provoking the decoupling of the parts and breaking the previous correlation between the analyzed time series. First, a worldwide analysis of seismicity is developed, focusing after in three regions, Colombia, Taiwan and the Iberian Peninsula. The seismicity data for the global analysis are obtained from the Centennial Catalog, while local catalogs are used for the regional study. Then, the BD hypothesis is tested in three seismic stations in Colombia and five in Taiwan; for that purpose, a selection of almost 4000 waveforms are effectively used from a total of almost 48000 of the study areas, for the coda Q quality factor analysis. The global and regional seismicity analysis allows the detection of space-time evolution trends with no easy explanation and that are attributed to external manifestations of the Earth¿s interior dynamic processes in the mantle. The detailed seismicity analysis in the 8 studied stations characterizes the brittle part. The waveforms in each station are used to determine the time series of coda Q in a time window of around 14 years. First, its space-time variation and depth dependence are studied, finding significant changes that correlate with local geotectonic structures. Besides, specific time series that characterize the ductile part are obtained. The correlation analysis and the one of the time variation of the central correlation coefficient have allowed evaluating the BD model. A new technique that allows the construction of time series of this coefficient is proposed, in a way that following and detecting the correlation/uncorrelation of the seismicity and Q time series can be done continuously. Therefore, calm and enhanced activity periods can be firmly established in the BD theory. By applying the technique to different geotectonic locations we find cases in which the behavior obeys the theory, whilst for others the validity is unclear. In the former, high values of the central correlation coefficient, above 0.6, are observed during calm periods; this value decreases drastically some time before the occurrence of a major earthquake. In the latter, the correlation is found to be, in most cases, permanently low, what can be attributed to a inexistent or poorly developed BD interaction zone, since, in most cases, these regions are ruled by complex geotectonic structures and a relatively high frequency of major earthquakes.

  • Identification of modal parameters: radar measurements and of ambient vibrations measurements

     Negulescu, Caterina; Raucoules, Daniel; Roullé, Agathe; Monfort, D.; Dewez, Thomas; Colas, B.; Luzi, G.; Crosetto ,, Michele; Pujades Beneit, Luis Gonzaga
    World Conference on Earthquake Engineering
    p. 1-10
    Presentation's date: 2012-09
    Presentation of work at congresses

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  • Probabilistic assessment of the seismic risk of Barcelona

     Aguilar Meléndez, Armando; García-Elías, A.; Pujades Beneit, Luis Gonzaga; Barbat Barbat, Horia Alejandro; Lantada Zarzosa, Nieves; Ordaz Schroeder, Mario Gustavo
    World Conference on Earthquake Engineering
    p. 1-7
    Presentation's date: 2012-09
    Presentation of work at congresses

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  • Probabilistic vulnerability assessment of a reinforced concrete structure by using a 3-D model

     Vargas Alzate, Yeudy Felipe; Barbat Barbat, Horia Alejandro; Pujades Beneit, Luis Gonzaga; Hurtado Gómez, Jorge Eduardo
    World Conference on Earthquake Engineering
    p. 1-9
    Presentation's date: 2012-09
    Presentation of work at congresses

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  • Seismic performance of unreinforced masonry buildings: application to Barcelona, Spain

     Avila Haro, Jorge Arturo; Gonzalez Drigo, Jose Ramon; Vargas Alzate, Yeudy Felipe; Pujades Beneit, Luis Gonzaga; Barbat Barbat, Horia Alejandro; Cattari, Serena
    World Conference on Earthquake Engineering
    p. 1-10
    Presentation's date: 2012-09-24
    Presentation of work at congresses

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    Probabilistic assessment of the seismic damage in reinforced concrete buildings  Open access

     Barbat Barbat, Horia Alejandro; Vargas Alzate, Yeudy Felipe; Pujades Beneit, Luis Gonzaga; Hurtado Gómez, Jorge Eduardo
    International Symposium Computational Civil Engineering
    p. 43-61
    Presentation's date: 2012-05-25
    Presentation of work at congresses

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    The main objective of this article is to assess the expected seismic damage in reinforced concrete buildings from a probabilistic point of view by using Monte Carlo simulation. To do that, the seismic behavior of the building is studied by using random capacity obtained by considering the mechanical properties of the materials as random variables. Starting from the capacity curves, one can obtain the damage states and the fragility curves as well as to develop curves describing the expected seismic damage of the structures as a function of a seismic hazard characteristic. The latter can be calculated using the capacity spectrum and the demand spectrum according to the methodology proposed by the RISK-UE project. For defining the seismic demand as a random variable, a set of real accelerograms are obtained from the European and Spanish databases in such a way that the mean of their elastic response spectra is similar to an elastic response spectrum selected from Eurocode 8. In order to combine the uncertainties associated with the seismic action and the mechanical properties of materials, two procedures are considered for obtaining functions which relates the PGA to the maximum spectral displacements. The first one is based on a series of nonlinear dynamic analyses. The second one is based on the well known procedure named equal displacement approximation exposed in ATC 40. After applying both procedures, the probability density functions of the maximum displacement at the roof of the building are obtained and compared. The expected structural damage is finally obtained by replacing the spectral displacement obtained by using the ATC 40 and the incremental dynamic procedure. In the damage functions the results obtained from incremental static and dynamic analyses are finally compared and discussed from a probabilistic point of view.

    The main objective of this article is to assess the expected seismic damage in reinforced concrete buildings from a probabilistic point of view by using Monte Carlo simulation. To do that, the seismic behavior of the building is studied by using random capacity obtained by considering the mechanical properties of the materials as random variables. Starting from the capacity curves, one can obtain the damage states and the fragility curves as well as to develop curves describing the expected seismic damage of the structures as a function of a seismic hazard characteristic. The latter can be calculated using the capacity spectrum and the demand spectrum according to the methodology proposed by the RISK-UE project. For defining the seismic demand as a random variable, a set of real accelerograms are obtained from the European and Spanish databases in such a way that the mean of their elastic response spectra is similar to an elastic response spectrum selected from Eurocode 8. In order to combine the uncertainties associated with the seismic action and the mechanical properties of materials, two procedures are considered for obtaining functions which relates the PGA to the maximum spectral displacements. The first one is based on a series of nonlinear dynamic analyses. The second one is based on the well known procedure named equal displacement approximation exposed in ATC 40. After applying both procedures, the probability density functions of the maximum displacement at the roof of the building are obtained and compared. The expected structural damage is finally obtained by replacing the spectral displacement obtained by using the ATC 40 and the incremental dynamic procedure. In the damage functions the results obtained from incremental static and dynamic analyses are finally compared and discussed from a probabilistic point of view.

  • Effects on the predominant periods due to abrupt lateral soil heterogeneities

     Salinas Naval, Victor; Santos Assunçao, Sonia Alexandra; Caselles Magallon, Jose Oriol; Perez Gracia, Maria de La Vega; Pujades Beneit, Luis Gonzaga; Clapes Boixader, Jaime
    World Conference on Earthquake Engineering
    p. 1-10
    Presentation's date: 2012-09
    Presentation of work at congresses

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  • Seismic risk scenarios in a cross-border zone of the Pyrenees

     Monfort, D.; Negulescu, Caterina; Roullé, Agathe; Colas, B.; Lantada Zarzosa, Nieves; Valcarcel Torres, Jairo Andres; Rodríguez, J.; Pujades Beneit, Luis Gonzaga; Barbat Barbat, Horia Alejandro; Irizarry, Janira; Susagna Vidal, Teresa; Macau, Albert; Figueras Vila, Sara; Goula Suriñach, Xavier
    World Conference on Earthquake Engineering
    p. 1-10
    Presentation's date: 2012-09
    Presentation of work at congresses

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  • Deterministic and probabilistic earthquake scenarios for the seismic risk analysis of URM buildings

     Avila Haro, Jorge Arturo; Gonzalez Drigo, Jose Ramon; Vargas Alzate, Yeudy Felipe; Pujades Beneit, Luis Gonzaga; Barbat Barbat, Horia Alejandro
    International Conference on Fracture and Damage Mechanics
    p. 537-540
    DOI: 10.4028/www.scientific.net/KEM.525-526.537
    Presentation's date: 2012-09-19
    Presentation of work at congresses

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  • Smart scaling of accelerograms applied to the study of steel buildings

     Bermúdez, C.A.; Hurtado Gómez, Jorge Eduardo; Barbat Barbat, Horia Alejandro; Pujades Beneit, Luis Gonzaga
    World Conference on Earthquake Engineering
    p. 1-10
    Presentation's date: 2012-09
    Presentation of work at congresses

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  • Seismic risk assessment for the city of Girona, Spain

     Irizarry, Janira; Macau, Albert; Figueras Vila, Sara; Goula Suriñach, Xavier; Lantada Zarzosa, Nieves; Vendrell, S.; Pujades Beneit, Luis Gonzaga; Blázquez, A.
    World Conference on Earthquake Engineering
    p. 1-10
    Presentation's date: 2012-09
    Presentation of work at congresses

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  • Ground-shaking scenarios and urban risk evaluation of Barcelona using the Risk-UE capacity spectrum based method

     Irizarry, Janira; Lantada Zarzosa, Nieves; Pujades Beneit, Luis Gonzaga; Barbat Barbat, Horia Alejandro; Goula Suriñach, Xavier; Susagna Vidal, Teresa; Roca, A.
    Bulletin of earthquake engineering
    Vol. 9, num. 2, p. 441-466
    DOI: 10.1007/s10518-010-9222-6
    Date of publication: 2011-04
    Journal article

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    Seismic risk analysis of urban non-engineered buildings: application to an informal settlement in Mérida, Venezuela  Open access

     Castillo, A.; Lopez Almansa, Francisco; Pujades Beneit, Luis Gonzaga
    Natural hazards
    Vol. 59, num. 2, p. 891-916
    DOI: 10.1007/s11069-011-9805-9
    Date of publication: 2011-11
    Journal article

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    Seismic risk scenarios are obtained for an informal settlement in Mérida (Venezuela), which is representative of an important number of urban areas in earthquake-prone regions of the developing world. The vulnerability indices of the buildings range between 0.64 and 0.80 on a scale of 0 to 1. In an intensity IX earthquake scenario, more than 32% of the buildings would suffer damage of grade 4 (extensive) or greater. A structural analysis of the buildings in the study area shows that they are unsafe for gravity loads, and that the seismic demands exceed the strength of the constructions. Simple and comparatively inexpensive measures can improve the seismic performance of these buildings; the vulnerability can be reduced by about 51%. In an intensity IX earthquake scenario the expected economic loss before retrofitting the buildings is US$5.36 million, with 275 fatalities; once retrofit has been carried out, the resulting figures are US$0.39 million and 10 fatalities. Retrofit would cost US$1.04 million, whereas reconstruction would cost US$19 million.

    The final publication is available at Springer via http://dx.doi.org/10.1007/s11069-011-9805-9

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    Vulnerability and risk evaluation for a reinforced concrete frame  Open access

     Olteanu, Ioana; Vargas Alzate, Yeudi Felipe; Barbat Barbat, Horia Alejandro; Budescu, Mihai; Pujades Beneit, Luis Gonzaga
    The Bulletin of the Polytechnic Institute of Jassy, Construction. Architecture Section
    Vol. LVII (LXI), num. 3, p. 9-20
    Date of publication: 2011-08
    Journal article

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    Vulnerability and risk assessment can be evaluated in a deterministic or a probabilistic way and this paper makes a comparison between the two approaches. A 2-D reinforced concrete frame, design according to the Romanian norm, was studied. Starting from the capacity curve obtained with a static non-linear analysis, fragility curves were ploted and an average damage index for the performance point of the structure was calculated. In the probabilistic approach the influence of uncertainties in the damage states thresholds is investigated on fragility and vulnerability curves. The obtained results for two coefficients of variation of the damage states thresholds simulated as random variables, meaning 10% and 20%, are also compared. The used procedures are based on the capacity spectrum method and on Monte Carlo simulations.

    Vulnerability and risk assessment can be evaluated in a deterministic or a probabilistic way and this paper makes a comparison between the two approaches. A 2-D reinforced concrete frame, design according to the Romanian norm, was studied. Starting from the capacity curve obtained with a static non-linear analysis, fragility curves were ploted and an average damage index for the performance point of the structure was calculated. In the probabilistic approach the influence of uncertainties in the damage states thresholds is investigated on fragility and vulnerability curves. The obtained results for two coefficients of variation of the damage states thresholds simulated as random variables, meaning 10% and 20%, are also compared. The used procedures are based on the capacity spectrum method and on Monte Carlo simulations.

  • Evaluación integrada de la seguridad de hospitales: implicaciones en la resiliencia de las comunidades

     Valcarcel Torres, Jairo Andrés; Pujades Beneit, Luis Gonzaga; Barbat Barbat, Horia Alejandro; Mora Cuevas, Miguel; Cardona Arboleda, Omar Dario
    Revista internacional de ingeniería de estructuras
    Vol. 16, num. 1, p. 68-91
    Date of publication: 2011-04
    Journal article

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    The objective of ¿safe hospitals from disasters¿ promoted by the World Health Organization suggests the evaluation of the physical vulnerability of facilities as well as the socioeconomic fragility of communities. According to this goal, this work presents a Hospital Risk Index by considering: a) structural vulnerability, which is considered by means of capacity and fragility curves, b) non-structural vulnerability, related to the fragility of contents, medical equipment, architectonic elements, and lifelines, c) response capacity, that evaluates the quality of emergency and contingency plans, workforces, logistics planning in emergency situations and simulation drills ,d) supply indicators refers to the size and attention level of the hospital and e) fragility and resilience of the community. These indicators are applied to the public hospitals of Catalonia, Spain, resulting in a decision-making tool for setting priorities for risk management of health systems.

  • EVALUACIÓN PROBABILÍSTA DEL RIESGO SÍSMICO DE EDIFICIOS EN ZONAS URBANAS

     Aguilar Meléndez, Armando
    Department of Geotechnical Engineering and Geo-Sciences, Universitat Politècnica de Catalunya
    Theses

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  • Modelización de un edificio de mampostería no reforzada característico del distrito del eixample de Barcelona, España

     Avila Haro, Jorge Arturo; Gonzalez Drigo, Jose Ramon; Pujades Beneit, Luis Gonzaga; Barbat Barbat, Horia Alejandro
    Congreso Nacional de Ingeniería Sísmica
    Presentation's date: 2011-05-18
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  • Riesgo sísmico de los edificios agregados en la ciudad de Barcelona (España)

     Gonzalez Drigo, Jose Ramon; Avila Haro, Jorge Arturo; Pujades Beneit, Luis Gonzaga; Barbat Barbat, Horia Alejandro
    Congreso Nacional de Ingeniería Sísmica
    p. 55
    Presentation's date: 2011-05-20
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    Radar de subusuelo para el estudio no destructivo de estructuras históricas: ¿Que información aporta?  Open access

     Perez Gracia, Maria de La Vega; Santos Assunçao, Sonia Alexandra; Pujades Beneit, Luis Gonzaga
    Congreso Español de Ensayos No Destructivos
    p. 171-180
    Presentation's date: 2011-06-15
    Presentation of work at congresses

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    Los ensayos no destructivos en estructuras históricas con radar de subsuelo (GPR) son cada vez más frecuentes. Proporcionan información sobre elementos internos de la estructura, mostrando su situación y, en ocasiones, confirmando su existencia. También permiten definir la distribución de diferentes materiales interiores al medio, como se puede ver en el ejemplo mostrado en este artículo. Aunque su uso habitual es para determinar posición y profundidad de elementos embebidos en un medio, el radar de subsuelo es una herramienta que también se puede utilizar para obtener una información más extensa y detallada de dicho medio. En estudios de patrimonio, un análisis de gran interés es la determinación de sectores afectados por el agua. Además de definir zonas en las que puede haberse presentado un problema de humedad, ¿es posible conocer aproximadamente el contenido de agua presente en un muro o en otras estructuras? En este trabajo se presentan algunos resultados experimentales en los que se analiza la amplitud, la frecuencia y la velocidad de la señal, comparándolos con medidas del contenido de agua y con modelos teóricos. Los resultados parecen indicar que algunos parámetros de la señal que proporciona este método no destructivo puede utilizarse para estimar la humedad del medio.

  • Contribución a los estudios de riesgo sísmico a escala municipal en Cataluña

     Goula Suriñach, Xavier; Valcarcel Torres, Jairo Andres; Pujades Beneit, Luis Gonzaga; Barbat Barbat, Horia Alejandro; Susagna, Teresa; Irizarry, Janira; Lantada Zarzosa, Nieves; Hermosilla, S.; Font, M.; Gasulla, Nuria
    Congreso Nacional de Ingeniería Sísmica
    p. 1-9
    Presentation's date: 2011-05-19
    Presentation of work at congresses

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    En los últimos años han visto la luz metodologías de tipo avanzado para la evaluación del riesgo, como el programa Hazus-MH (FEMA/NIBS, 2003) y el proyecto Risk-UE (Mouroux y Lebrun, 2006) los cuales consideran espectros de respuesta uniformes para caracterizar el movimiento del suelo y espectros de capacidad para caracterizar la vulnerabilidad de los edificios. Esta metodología ha sido aplicada al estudio del riesgo sísmico en la ciudad de Barcelona (Irizarry, 2004, Lantada, 2007). Para actualizar en algunos aspectos el análisis de riesgo del Plan de emergencias sísmicas en Cataluña (SISMICAT) y contribuir al estudio de riesgo a escala municipal, se propone una metodología de tipo “intermedio” aplicable al conjunto de HOSPITALES y de CENTROS EDUCATIVOS u otros edificios vulnerables y esenciales. Los márgenes de seguridad del edificio se calculan a partir de la comparación entre los espectros de demanda y de capacidad. Se muestra la aplicación de la metodología a un edificio esencial y estructuralmente complejo de la ciudad de Barcelona, y los resultados se comparan con otras evaluaciones previamente realizadas.

  • Incremental dynamic analysis and pushover analysis: a probabilistic comparison

     Vargas Alzate, Yeudy Felipe; Pujades Beneit, Luis Gonzaga; Barbat Barbat, Horia Alejandro; Hurtado Gómez, Jorge Eduardo
    International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering
    p. 1-11
    Presentation's date: 2011-05-26
    Presentation of work at congresses

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    Capacity-spectrum-based-methods are also used for assessing the vulnerability and risk of existing buildings. Capacity curves are usually obtained by means of nonlinear static analysis. Incremental Dynamic Analysis is another powerful tool based on nonlinear dynamic analysis. This method is similar to the pushover analysis as the input is incrementally increased but it is different as it is based on dynamic analysis. Moreover, it is well known that the uncertainties associated to the structural response can be significant, because of the un-certainties involved in the mechanical properties of the materials, and because the expected seismic actions are also highly uncertain. In this work selected mechanical properties are considered as random variables and the seismic hazard is considered in a probabilistic way. A number of accelerograms of actual European seismic events have been selected in such a way that their response spectra fitted well the response spectra provided by the seismic codes for the zone where the target building is constructed. In this work a fully probabilistic ap-proach is tackled by means of Monte Carlo simulation and it is applied to a detailed study of the seismic response of a reinforced concrete building. The building is representative for multifamily buildings in Spain but the methods used and the results obtained can be extended to other types of buildings. The main purposes of this work are 1) to analyze the differences when static and dynamic techniques are used and 2) to obtain a measure of the uncertainties involved in the assessment of the vulnerability of structures. The results show that static based procedures are somehow conservative and that uncertainties increase with the severity of the seismic actins and with the damage. Low damage state fragility curves have little uncertainty while high damage grades fragility curves show great scattering.

    Capacity-spectrum-based-methods are also used for assessing the vulnerability and risk of existing buildings. Capacity curves are usually obtained by means of nonlinear static analysis. Incremental Dynamic Analysis is another powerful tool based on nonlinear dynamic analysis. This method is similar to the pushover analysis as the input is incrementally increased but it is different as it is based on dynamic analysis. Moreover, it is well known that the uncertainties associated to the structural response can be significant, because of the un-certainties involved in the mechanical properties of the materials, and because the expected seismic actions are also highly uncertain. In this work selected mechanical properties are considered as random variables and the seismic hazard is considered in a probabilistic way. A number of accelerograms of actual European seismic events have been selected in such a way that their response spectra fitted well the response spectra provided by the seismic codes for the zone where the target building is constructed. In this work a fully probabilistic ap-proach is tackled by means of Monte Carlo simulation and it is applied to a detailed study of the seismic response of a reinforced concrete building. The building is representative for multifamily buildings in Spain but the methods used and the results obtained can be extended to other types of buildings. The main purposes of this work are 1) to analyze the differences when static and dynamic techniques are used and 2) to obtain a measure of the uncertainties involved in the assessment of the vulnerability of structures. The results show that static based procedures are somehow conservative and that uncertainties increase with the severity of the seismic actins and with the damage. Low damage state fragility curves have little uncertainty while high damage grades fragility curves show great scattering.

  • Comparación probabilista entre el análisis estático y dinámico incremental de edificios de hormigón armado

     Vargas Alzate, Yeudy Felipe; Barbat Barbat, Horia Alejandro; Pujades Beneit, Luis Gonzaga; Hurtado Gómez, Jorge Eduardo
    Congresso de Métodos Numéricos em Engenharia
    p. 1-10
    Presentation's date: 2011-06-15
    Presentation of work at congresses

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    En la evaluación del riesgo sísmico de edificios, se han propuesto varias metodologías derivadas de la curva de capacidad obtenida por medio del análisis estático no lineal de carga incremental o análisis pushover. Por otra parte, el análisis dinámico incremental es una poderosa herramienta desarrollada recientemente, análoga al análisis pushover porque el PGA de la acción es incrementado obteniendo en cada paso de cálculo la respuesta dinámica máxima. Por tanto, es importante comparar los resultados obtenidos con estos dos métodos. Por otra parte, las incertidumbres asociadas a las propiedades mecánicas de los materiales y de la acción sísmica es otro aspecto importante que debe ser considerado en el estudio. Para incluir este enfoque probabilista, se estudia la respuesta estocástica de un modelo estructural mediante el método de Monte Carlo. La acción sísmica es tratada como una variable aleatoria tomando diferentes registros de aceleración compatibles con el espectro de respuesta elástica de una zona dado por las normas de diseño. El propósito de esta comparación es de obtener una medida del error en la evaluación del riesgo sísmico de las estructuras cuando la respuesta dinámica de una estructura es aproximada utilizando un procedimiento estático no lineal incremental. El estudio se aplica al caso de estructuras de hormigón armado comúnmente usadas en España. No obstante, las metodologías propuestas en este artículo pueden ser extendidas a cualquier tipo de edificio. Los resultados obtenidos mediante el procedimiento estático y dinámico son comparados y discutidos desde un punto de vista probabilista. Este análisis probabilista muestra que la dispersión de los resultados se incrementa cuando la estructura empieza a comportarse en régimen no lineal.

    En la evaluación del riesgo sísmico de edificios, se han propuesto varias metodologías derivadas de la curva de capacidad obtenida por medio del análisis estático no lineal de carga incremental o análisis pushover. Por otra parte, el análisis dinámico incremental es una poderosa herramienta desarrollada recientemente, análoga al análisis pushover porque el PGA de la acción es incrementado obteniendo en cada paso de cálculo la respuesta dinámica máxima. Por tanto, es importante comparar los resultados obtenidos con estos dos métodos. Por otra parte, las incertidumbres asociadas a las propiedades mecánicas de los materiales y de la acción sísmica es otro aspecto importante que debe ser considerado en el estudio. Para incluir este enfoque probabilista, se estudia la respuesta estocástica de un modelo estructural mediante el método de Monte Carlo. La acción sísmica es tratada como una variable aleatoria tomando diferentes registros de aceleración compatibles con el espectro de respuesta elástica de una zona dado por las normas de diseño. El propósito de esta comparación es de obtener una medida del error en la evaluación del riesgo sísmico de las estructuras cuando la respuesta dinámica de una estructura es aproximada utilizando un procedimiento estático no lineal incremental. El estudio se aplica al caso de estructuras de hormigón armado comúnmente usadas en España. No obstante, las metodologías propuestas en este artículo pueden ser extendidas a cualquier tipo de edificio. Los resultados obtenidos mediante el procedimiento estático y dinámico son comparados y discutidos desde un punto de vista probabilista. Este análisis probabilista muestra que la dispersión de los resultados se incrementa cuando la estructura empieza a comportarse en régimen no lineal.

  • Análisis estático y dinámico incremental de edificios de hormigón armado

     Vargas Alzate, Yeudy Felipe; Pujades Beneit, Luis Gonzaga; Barbat Barbat, Horia Alejandro; Hurtado Gómez, Jorge Eduardo
    Congreso Nacional de Ingeniería Sísmica
    p. 1-8
    Presentation's date: 2011-05-20
    Presentation of work at congresses

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    In the assessment of the seismic hazard of buildings, several methodologies have been proposed based on the capacity curve obtained via Pushover Analysis. On the other hand, the Incremental Dynamic Analysis is a powerful tool analogue to the pushover analysis because the input is increased and the maximum response of the structure is obtained in each increment. Therefore, it is important to compare the results obtained with these methodologies. On the other hand, the uncertainty associated to the structural behavior, because mechanical properties are random variables, and the uncertainty of the seismic hazard, is another important aspect that must be considered. In order to include this probabilistic approach, Monte Carlo simulation is applied to study the stochastic response of a building model. Besides, the seismic hazard is defined as a random variable taking several registers of acceleration compatible with acceleration response spectrum given for a zone. The results obtained from static and dynamic analyses are finally compared and discussed from a probabilistic point of view. This probabilistic analysis shows that the spread of the fragility curves increases with the damage state, thus rendering highly uncertain the curves obtained by probabilistic approaches.

    In the assessment of the seismic hazard of buildings, several methodologies have been proposed based on the capacity curve obtained via Pushover Analysis. On the other hand, the Incremental Dynamic Analysis is a powerful tool analogue to the pushover analysis because the input is increased and the maximum response of the structure is obtained in each increment. Therefore, it is important to compare the results obtained with these methodologies. On the other hand, the uncertainty associated to the structural behavior, because mechanical properties are random variables, and the uncertainty of the seismic hazard, is another important aspect that must be considered. In order to include this probabilistic approach, Monte Carlo simulation is applied to study the stochastic response of a building model. Besides, the seismic hazard is defined as a random variable taking several registers of acceleration compatible with acceleration response spectrum given for a zone. The results obtained from static and dynamic analyses are finally compared and discussed from a probabilistic point of view. This probabilistic analysis shows that the spread of the fragility curves increases with the damage state, thus rendering highly uncertain the curves obtained by probabilistic approaches.

  • Análisis de beneficio costo de la mitigación del riesgo sísmico de las escuelas de la Región Andina y de Centro América

     Valcarcel Torres, Jairo Andrés; Mora Cuevas, Miguel; Cardona Arboleda, Omar Dario; Pujades Beneit, Luis Gonzaga; Barbat Barbat, Horia Alejandro; Bernal Granados, Gabriel Andres
    Congreso Nacional de Ingeniería Sísmica
    p. 1-9
    Presentation's date: 2011-05-19
    Presentation of work at congresses

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    The observed damages in schools during earthquakes have encouraged the development of projects oriented to reduce its vulnerability. Those projects have been supported by damage assessments and Benefit Cost Analysis for specific scenarios. In this sense, this study presents a rough estimate of the seismic risk of the schools in the Andean Region and Central America following a probabilistic approach. This study encompasses: i) the definition of probabilistic seismic hazard models at the country level, using spectral ordinates as intensity measurements, ii) the estimation of the schools¿ built area, its economic value and geographical distribution, as well as its classification in structural typologies; iii) the selection of representative vulnerability curves for each structural typology; iv) the estimation of the Loss Exceedance Curve (LEC) and the Annual Average Loss (AAL) of the schools¿ built area in the current conditions as well as in the case of a hypothetical structural rehabilitation. The comparison of those results with the reinforcement costs leads to Benefit Cost ratios from a financial perspective. Thus, this study is useful for regional comparisons and national screening purposes, as a first step in guiding the national seismic risk reduction programs of the educational sector.

    The observed damages in schools during earthquakes have encouraged the development of projects oriented to reduce its vulnerability. Those projects have been supported by damage assessments and Benefit Cost Analysis for specific scenarios. In this sense, this study presents a rough estimate of the seismic risk of the schools in the Andean Region and Central America following a probabilistic approach. This study encompasses: i) the definition of probabilistic seismic hazard models at the country level, using spectral ordinates as intensity measurements, ii) the estimation of the schools’ built area, its economic value and geographical distribution, as well as its classification in structural typologies; iii) the selection of representative vulnerability curves for each structural typology; iv) the estimation of the Loss Exceedance Curve (LEC) and the Annual Average Loss (AAL) of the schools’ built area in the current conditions as well as in the case of a hypothetical structural rehabilitation. The comparison of those results with the reinforcement costs leads to Benefit Cost ratios from a financial perspective. Thus, this study is useful for regional comparisons and national screening purposes, as a first step in guiding the national seismic risk reduction programs of the educational sector.

  • Scénarios de risque sismique dans une zone transfrontalière des Pyrénées

     Monfort, Daniel; Lantada Zarzosa, Nieves; Goula Suriñach, Xavier; Barbat Barbat, Horia Alejandro; Negulescu, Caterina; Pujades Beneit, Luis Gonzaga; Susagna Vidal, Teresa; Valcarcel Torres, Jairo Andres; Rodríguez, Jessica
    Colloque National de l'Association Française du Génie Parasismique
    p. 191-199
    Presentation's date: 2011-09-08
    Presentation of work at congresses

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  • Generación de escenarios de riesgo sísmico en una zona transfronteriza del Pirineo

     Monfort, Daniel; Lantada Zarzosa, Nieves; Goula Suriñach, Xavier; Barbat Barbat, Horia Alejandro; Negulescu, Caterina; Pujades Beneit, Luis Gonzaga; Susagna, Teresa; Valcarcel Torres, Jairo Andres; Rodríguez, J.
    Congreso Nacional de Ingeniería Sísmica
    p. 1-9
    Presentation's date: 2011-05-19
    Presentation of work at congresses

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    Se presenta la evaluación del daño sísmico esperado, a nivel estadístico, en los municipios de la zona pirenaica formada por las comarcas de Saint-Béat y Luchon (Francia) y de la Val d’Aran (España). Esta zona ha sido seleccionada por la actividad sísmica observada y por su importante carácter turístico. El análisis de la vulnerabilidad sísmica de los edificios se realiza mediante los índices de vulnerabilidad RISK-UE. Este método define unos tipos constructivos basándose en las clases de vulnerabilidad de la escala de intensidades EMS-98. A partir de estos índices de vulnerabilidad y para un determinado nivel de acción sísmica se estima mediante funciones semi-empíricas la distribución del daño físico. Se han identificado las tipologías constructivas más representativas de los edificios residenciales de la zona, y su distribución por unidades de estudio, asociándolas a índices de vulnerabilidad, así como en edificios singulares; dicha información se ha integrado en un SIG. El escenario se ha hecho a partir de las intensidades observadas e interpretadas del terremoto de Vielha en 1923 (VIII). La repartición de los estados de daño físico directo obtenida servirá para estimar otros aspectos como daños a la población y costes económicos. Estos resultados serán útiles para la prevención y la protección civil.

  • Corrigendum to "Seismic damage evaluation in urban areas using a capacity spectrum based method: Application to Barcelona"

     Barbat Barbat, Horia Alejandro; Pujades Beneit, Luis Gonzaga; Lantada Zarzosa, Nieves; Moreno González, Rosángel
    Soil dynamics and earthquake engineering (1984)
    Vol. 30, num. 8, p. 767
    DOI: 10.1016/j.soildyn.2009.12.014
    Date of publication: 2010-08
    Journal article

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  • Seismic vulnerability and risk evaluation methods for urban areas: a review with application to a pilot area

     Barbat Barbat, Horia Alejandro; Carreño Tibaduiza, Martha Liliana; Pujades Beneit, Luis Gonzaga; Lantada Zarzosa, Nieves; Cardona, Omar. D.; Marulanda Fraume, Mabel Cristina
    Structure and infrastructure engineering
    Vol. 6, num. 1-2, p. 17-38
    DOI: 10.1080/15732470802663763
    Date of publication: 2010-02
    Journal article

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    The most relevant seismic vulnerability and risk analysis methods are discussed and compared in this article using, as a pilot urban area, the city of Barcelona, Spain, where risk studies have been carried out over the last 15 years in the framework of different research projects. Most of the buildings in Barcelona, which have unreinforced masonry structure or reinforced concrete structure with waffled slab floors, show a high degree of vulnerability to earthquakes. The physical seismic risk but also the socio-economic implications of risk are considered in the article. The robustness of the innovative holistic approach, based on indicators related to the physical exposure, the social fragilities and the lack of resilience of urban area, is also proved. Using a geographic information system (GIS), the seismic risk results are described by means of scenarios of expected losses, but also as scenarios of probabilities of occurrence of predefined damage states.

  • Experimental and analytical research on seismic vulnerability of low-cost ferrocement dwelling houses

     Bedoya-Ruiz, Daniel; Eduardo Hurtado, Jorge; Pujades Beneit, Luis Gonzaga
    Structure and infrastructure engineering
    Vol. 6, num. 1-2, p. 55-62
    DOI: 10.1080/15732470802663789
    Date of publication: 2010
    Journal article

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  • Access to the full text
    Seismic hazard and risk scenarios for Barcelona, Spain, using the Risk-UE vulnerability index method  Open access

     Lantada Zarzosa, Nieves; Irizarry, Janira; Barbat Barbat, Horia Alejandro; Goula Suriñach, Xavier; Roca, A.; Susagna Vidal, Teresa; Pujades Beneit, Luis Gonzaga
    Bulletin of earthquake engineering
    Vol. 8, num. 2, p. 201-229
    DOI: 10.1007/s10518-009-9148-z
    Date of publication: 2010-04
    Journal article

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    The Vulnerability Index Method, in its version developed in the framework of the European project Risk-UE, has been adapted and applied in this article, to evaluate the seismic risk for the city of Barcelona (Spain) through a GIS based tool. According to this method, which defines five damage states, the action is expressed in terms of the macroseismic intensity and the seismic quality of the buildings by means of a vulnerability index. The probabilities of damage states are obtained considering a binomial or beta-equivalent probability distribution. The most relevant seismic risk evaluation results obtained, for current buildings and monuments of Barcelona, are given in the article as scenarios of expected losses.

    The original publication is available at http://www.springerlink.com

    Postprint (author’s final draft)

  • Erratum to Performance of buildings under earthquakes in Barcelona, Spain

     Barbat Barbat, Horia Alejandro; Pujades Beneit, Luis Gonzaga; Lantada Zarzosa, Nieves; Moreno González, Rosángel
    Computer-aided civil and infrastructure engineering
    Vol. 25, num. 3, p. 226
    DOI: 10.1111/j.1467-8667.2010.00660.x
    Date of publication: 2010-02-11
    Journal article

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  • Applying the H/V Method to Dense Cities. A Case Study of Valencia City

     Caselles Magallon, Jose Oriol; Perez Gracia, Maria de La Vega; Franklin, R S; Pujades Beneit, Luis Gonzaga; Navarro, M; Clapes Boixader, Jaime; Canas Torres, Jose Antonio; Garcia, F
    Journal of earthquake engineering
    Vol. 14, num. 2, p. 192-210
    DOI: 10.1080/13632460903086069
    Date of publication: 2010
    Journal article

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