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    Behavior, for the Lorca earthquake on 11-05-2011, of wide beam building designed without seismic considerations  Open access

     Domínguez Santos, David Jesús; Lopez Almansa, Francisco; Benavent Climent, Amadeo
    Informes de la construcción
    Date of publication: 2014
    Journal article

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    The recent earthquake in Lorca (11-05-2011) was the most destructive recorded event in Spain, despite its moderate magnitude. This paper describes the numerical simulation of the dynamic response to the main record of the Lorca earthquake of six 3 and 6-story buildings with one-way concrete slabs with wide beams; these buildings were designed without any seismic consideration. We have chosen this type of construction because it is potentially highly vulnerable. The six considered buildings were selected to represent a large number of buildings of this type in areas of low-to-medium seismicity (as Lorca) of Spain along the period 1974-1994. The results show that these buildings, even with the cooperation of the walls, do not have sufficient capacity to withstand the most severe component of the Lorca record.

    The recent earthquake in Lorca (11-05-2011) was the most destructive recorded event in Spain, despite its moderate magnitude. This paper describes the numerical simulation of the dynamic response to the main record of the Lorca earthquake of six 3 and 6-story buildings with one-way concrete slabs with wide beams; these buildings were designed without any seismic consideration. We have chosen this type of construction because it is potentially highly vulnerable. The six considered buildings were selected to represent a large number of buildings of this type in areas of low-to-medium seismicity (as Lorca) of Spain along the period 1974-1994. The results show that these buildings, even with the cooperation of the walls, do not have sufficient capacity to withstand the most severe component of the Lorca record.

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    Numerical seismic vulnerability analysis of mid-height steel buildings in Bogotá, Colombia  Open access

     Lopez Almansa, Francisco; Montaña Peña, Miguel Angel
    Journal of constructional steel research
    Date of publication: 2014-01
    Journal article

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    A number of mid-height steel buildings have been erected recently in Bogotá. Their seismic risk might be high, given the present microzonation of Bogotá and the lack of comprehensive previous studies; noticeably, the response reduction factors were commonly obtained only from general recommendations. The objective of this work is to investigate the seismic performance of these buildings. This study is carried out on eighteen representative prototype buildings. All these edifices have plan symmetry and are uniform along their height. The eighteen considered prototype buildings are generated by combining the values of three parameters: span-length (6 and 8 m), number of floors (5, 10 and 15) and earthquake-resistant systems (moment-resistant frames, concentrically-braced frames and eccentrically-braced frames - using chevron braces). The structures of each of these eighteen prototype buildings have been designed according to the former and to the current Colombian seismic design codes; in the former code two seismic zones are considered and in the current code such zones are coarsely subdivided in three and in five zones, respectively. The structural properties of the buildings designed with the former and the current Colombian codes are compared to investigate the practical repercussions of the new regulation. The vulnerability of these buildings has been evaluated by 2-D "push-over" analyses. The main objective of these analyses is to determine the response reduction factor; the obtained values are compared with the recommendations of the current Colombian seismic design code. As well, the seismic performances of the three considered earthquake-resistant systems are compared. © 2013 Elsevier Ltd.

    A number of mid-height steel buildings have been erected recently in Bogotá. Their seismic risk might be high, given the present microzonation of Bogotá and the lack of comprehensive previous studies; noticeably, the response reduction factors were commonly obtained only from general recommendations. The objective of this work is to investigate the seismic performance of these buildings. This study is carried out on eighteen representative prototype buildings. All these edifices have plan symmetry and are uniform along their height. The eighteen considered prototype buildings are generated by combining the values of three parameters: span-length (6 and 8 m), number of floors (5, 10 and 15) and earthquake-resistant systems (moment-resistant frames, concentrically-braced frames and eccentrically-braced frames - using chevron braces). The structures of each of these eighteen prototype buildings have been designed according to the former and to the current Colombian seismic design codes; in the former code two seismic zones are considered and in the current code such zones are coarsely subdivided in three and in five zones, respectively. The structural properties of the buildings designed with the former and the current Colombian codes are compared to investigate the practical repercussions of the new regulation. The vulnerability of these buildings has been evaluated by 2-D

    Published in Journal of constructional steel research by ELSEVIER. The original publication is available at http://www.sciencedirect.com/science/article/pii/S0143974X13002538

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    Vulnerability analysis of RC buildings with wide beams located in moderate seismicity regions  Open access

     Lopez Almansa, Francisco; Domínguez Santos, David Jesús; Benavent Climent, Amadeu
    Engineering structures
    Date of publication: 2013-01
    Journal article

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    A significant number of short-to-mid height RC buildings with wide beams have been constructed in areas of moderate seismicity of Spain, mainly for housing and administrative use. The buildings have a framed structure with one-way slabs; the wide beams constitute the distinctive characteristic, their depth being equal to that of the rest of the slab, thus providing a flat lower surface, convenient for construction and the layout of facilities. Seismic behavior in the direction of the wide beams appears to be deficient because of: (i) low lateral strength, mainly because of the small effective depth of the beams, (ii) inherent low ductility of the wide beams, generated by high amount of reinforcement, (iii) the big strut compressive forces developed inside the column-beam connections due to the low height of the beams, and (iv) the fact that the wide beams are wider than the columns, meaning that the contribution of the outer zones to the resistance of the beam-column joints is unreliable because there is no torsion reinforcement. In the orthogonal direction, the behavior is worse since the only members of the slabs that contribute to the lateral resistance are the joists and the façade beams. Moreover, these buildings were designed with codes that did not include ductility requirements and required only a low lateral resistance; indeed, in many cases, seismic action was not considered at all. Consequently, the seismic capacity of these structures is not reliable. The objective of this research is to assess numerically this capability, whereas further research will aim to propose retrofit strategies. The research approach consists of: (i) selecting a number of 3- story and 6-story buildings that represent the vast majority of the existing ones and (ii) evaluating their vulnerability through three types of analyses, namely: code-type, push-over and nonlinear dynamic analysis. Given the low lateral resistance of the main frames, the cooperation of the masonry infill walls is accounted for; for each representative building, three wall densities are considered. The results of the analyses show that the buildings in question exhibit inadequate seismic behavior in most of the examined situations. In general, the relative performance is less deficient for target drift CP (Collapse Prevention) than for IO (Immediate Occupancy). Since these buildings are selected to be representative of the vast majority of buildings with wide beams that were constructed in Spain without accounting for any seismic consideration, our conclusions can be extrapolated to a broader scenario.

    Published in Engineering structures by ELSEVIER. The original publication is available at http://www.sciencedirect.com/science/article/pii/S0141029612004774

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    Design energy input spectra for high seismicity regions based on Turkish registers  Open access

     Lopez Almansa, Francisco; Yazgan, Ahmet Utku; Benavent Climent, Amadeo
    Bulletin of earthquake engineering
    Date of publication: 2013-01
    Journal article

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    This work proposes design energy spectra in terms of an equivalent velocity, intended for regions with design peak acceleration 0.3 g or higher. These spectra were derived through linear and nonlinear dynamic analyses on a number of selected Turkish strong ground motion records. In the long and mid period ranges the analyses are linear, given the relative insensitivity of the spectra to structural parameters other than the fundamental period; conversely, in the short period range, the spectra are more sensitive to the structural parameters and, hence, nonlinear analyses are required. The selected records are classified in eight groups with respect to soil type (stiff or soft soil), the severity of the earthquake in terms of surface magnitude M-s (M-s <= 5.5 and M-s > 5.5) and the relevance of the near-source effects (impulsive or vibratory). For each of these groups, median and characteristic spectra are proposed; such levels would respectively correspond to 50 and 95 % percentiles. These spectra have an initial linear growing branch in the short period range, a horizontal branch in the mid period range and a descending branch in the long period range. Empirical criteria for estimating the hysteretic energy from the input energy are suggested. The proposed design spectra are compared with those obtained from other studies.

    This work proposes design energy spectra in terms of an equivalent velocity, intended for regions with design peak acceleration 0.3 g or higher. These spectra were derived through linear and nonlinear dynamic analyses on a number of selected Turkish strong ground motion records. In the long and mid period ranges the analyses are linear, given the relative insensitivity of the spectra to structural parameters other than the fundamental period; conversely, in the short period range, the spectra are more sensitive to the structural parameters and, hence, nonlinear analyses are required. The selected records are classified in eight groups with respect to soil type (stiff or soft soil), the severity of the earthquake in terms of surface magnitude M-s (M-s <= 5.5 and M-s > 5.5) and the relevance of the near-source effects (impulsive or vibratory). For each of these groups, median and characteristic spectra are proposed; such levels would respectively correspond to 50 and 95 % percentiles. These spectra have an initial linear growing branch in the short period range, a horizontal branch in the mid period range and a descending branch in the long period range. Empirical criteria for estimating the hysteretic energy from the input energy are suggested. The proposed design spectra are compared with those obtained from other studies.

    The final publication is available at Springer via http://dx.doi.org/10.1007/s10518-012-9415-2

  • Evaluación de la capacidad sismorresistente de edificios con vigas planas situados en zonas de España de sismicidad baja a moderada.

     Domínguez Santos, David Jesús
    Defense's date: 2012-06-04
    Department of Structural Architecture, Universitat Politècnica de Catalunya
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  • Proposal of energy spectra for earthquake resistant design based on turkish registers  Open access

     Yazgan, Ahmet Utku
    Defense's date: 2012-09-07
    Department of Geotechnical Engineering and Geo-Sciences, Universitat Politècnica de Catalunya
    Theses

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    This work proposes design energy spectra in terms of an equivalent velocity, intended for regions with design peak acceleration 0.3 g or higher. These spectra have been derived through linear and nonlinear dynamic analyses on a number of Turkish selected strong ground motion records. In the long and mid period ranges the analyses are linear, taking profit of the rather insensitivity of the spectra to the structural parameters other than the fundamental period; conversely, in the short period range, the spectra are more sensitive to the structural parameters and, hence, nonlinear analyses are required. The selected records are classified in eight groups with respect to the soil type (stiff soil and soft soil), the severity of the earthquake in terms of surface magnitude Ms (Ms ¿ 5.5 and Ms > 5.5) and the relevance of the near-source effects (impulsive and vibratory). For each of these groups, median and characteristic spectra are proposed; such levels are intended to correspond to 50% and to 95% percentiles, respectively. These spectra have an initial linear growing branch in the short period range, a horizontal branch in the mid period range and a descending branch in the long period range. Empirical criteria for estimating the hysteretic energy from the input energy are suggested. The proposed design spectra are compared with those obtained from other studies.

    Este trabajo propone espectros de proyecto de energía en términos de velocidad equivalente, destinados a regiones con aceleración sísmica de proyecto 0.3 g o superior. Estos espectros se han obtenido a través de análisis dinámicos lineales y no lineales en una serie de registros sísmicos fuertes de Turquía. En los tramos de períodos largos y medianos los análisis son lineales, aprovechando la insensibilidad de los espectros con respecto a los parámetros estructurales, excepto el período fundamental y la masa; por el contrario, en el tramo de períodos cortos, los espectros son más sensibles a los parámetros estructurales y, por lo tanto, es necesario es necesario efectuar análisis no lineales. Los registros seleccionados se clasifican en ocho grupos con respecto al tipo de suelo (suelo duro y suelo blando), a la gravedad del terremoto en términos de magnitud superficial (Ms ≤ 5,5 y Ms > 5,5) y la relevancia de efectos de proximidad de falla (registros impulsivos y vibratorios). Para cada uno de estos grupos, se proponen espectros medianos y característicos; dichos niveles corresponden a los percentiles de 50% y 95%, respectivamente. Estos espectros tienen una rama inicial lineal creciente en el intervalo de períodos cortos, una rama horizontal en el intervalo de períodos medios y una rama descendente en el intervalo de períodos largos. Se proponen criterios empíricos para estimar la energía histéretica a partir de la energía de entrada. Los espectros de proyecto propuestos se comparan con los obtenidos a partir de otros estudios.

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    A numerical model of the structural behavior of buckling-restrained braces  Open access

     Lopez Almansa, Francisco; Castro Medina, Juan Carlos; Oiler, S.
    Engineering structures
    Date of publication: 2012-08
    Journal article

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    This work presents a numerical model of the cyclic structural behavior of dissipative buckling-restrained braces, commonly used as an alternative to classical concentric braces for seismic protection of building frames and other structures. Such devices are usually composed of a slender steel core embedded in a stockiest casing that is intended to prevent its buckling when it is under compression. The casing is made either of mortar or steel, and a sliding interface is interposed between the core and the casing to prevent excessive shear stress transfer. The behavior of the steel core is described by a damage and plasticity model; the behavior of the mortar casing is described by an isotropic damage model and the sliding behavior of the interface is described by a contact penalty model. These three models are implemented in the Abaqus software package following an explicit formulation. The ability of this algorithm to reproduce the cyclic behavior of buckling-restrained braces is verified in a number of representative yet simple situations. The accuracy of the proposed model is checked by comparison with experimental results; a satisfactory agreement is obtained. Preliminary conclusions are issued and further research needs are identified.

    This work presents a numerical model of the cyclic structural behavior of dissipative buckling-restrained braces, commonly used as an alternative to classical concentric braces for seismic protection of building frames and other structures. Such devices are usually composed of a slender steel core embedded in a stockiest casing that is intended to prevent its buckling when it is under compression. The casing is made either of mortar or steel, and a sliding interface is interposed between the core and the casing to prevent excessive shear stress transfer. The behavior of the steel core is described by a damage and plasticity model; the behavior of the mortar casing is described by an isotropic damage model and the sliding behavior of the interface is described by a contact penalty model. These three models are implemented in the Abaqus software package following an explicit formulation. The ability of this algorithm to reproduce the cyclic behavior of buckling-restrained braces is verified in a number of representative yet simple situations. The accuracy of the proposed model is checked by comparison with experimental results; a satisfactory agreement is obtained. Preliminary conclusions are issued and further research needs are identified.

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    Seismic performance of buildings with thin RC bearing walls  Open access

     Gonzáles Fernández, Helbert; Lopez Almansa, Francisco
    Engineering structures
    Date of publication: 2012-01
    Journal article

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    up to five stories) with thin RC shear-walls have been constructed for low-cost dwellings in Bolivia, Colombia, Ecuador, Mexico, Peru, Venezuela, and other countries located in seismic-prone regions. These walls are 10 cm thick and their reinforcement consists mainly of a single layer of welded wire mesh. This construction technology offers two main advantages: economy and rapidity of construction. These buildings do not fulfill the international seismic codes but some national regulations are less demanding, not preventing the use of thin bearing walls. These buildings might be vulnerable to earthquakes because of their low ductility, the insufficiency of the experimental information, the absence of observed damages and, in some cases, poor construction quality. This work describes the initial steps of a wider research aiming at providing reliable seismic design guidelines for thin-wall buildings; the initial objectives are analyzing the seismic performance of these buildings, proposing preliminary design criteria and identifying further research needs. This research focuses on buildings located in Peru, being representative of the situations in the other countries. The vulnerability is numerically evaluated by push-over and nonlinear time history analyses; the structural parameters are obtained from available testing information. The obtained results show that the seismic strength of the analyzed buildings is insufficient; however, minor changes in the structural design might improve significantly their seismic performance. Economical and easy-to-implement design recommendations are issued.

  • 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
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  • Comportamiento sísmico de edificios con muros delgados de hormigón. Aplicación a zonas de alta sismicidad de Perú  Open access

     Gonzáles Fernández, Helbert
    Defense's date: 2011-02-04
    Department of Geotechnical Engineering and Geo-Sciences, Universitat Politècnica de Catalunya
    Theses

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    En este trabajo se presenta un estudio numérico de la vulnerabilidad sísmica de edificios de muros delgados construidos en Perú. Estos edificios se vienen construyendo desde hace unas décadas, especialmente para viviendas de bajo coste (por economía y rapidez de construcción).Este estudio se centra en los casos más comunes, los cuales no suelen exceder las cinco plantas; las luces son reducidas, habitualmente hasta 5 m, y no suelen haber sótanos; los muros tienen 10 cm de espesor y su armadura consiste en una única capa de malla electrosoldada, con algunas barras adicionales de 12 mm de diámetro en los extremos. Las losas tienen, en general, 12 cm de canto; la cimentación suele consistir en una losa de 20 a 25 cm de espesor apoyada sobre terreno mejorado. No existen pilares, siendo los muros los únicos elementos sustentantes; en las fachadas éstos se suelen conectar a la altura de cada planta mediante vigas de acoplamiento de unos 50 cm de altura, sin características sismorresistentes adecuadas. Las densidades de muros en cada dirección oscilan entre 2% y 5%, con algunas excepciones; los muros en direcciones perpendiculares suelen estar conectados entre sí. La resistencia característica del hormigón es 17,5 MPa y la calidad global de la construcción es, en general, aceptable. Estos edificios han sido proyectados de acuerdo con la normativa peruana, cuyos requerimientos, a pesar de contener prescripciones específicas para estos edificios, podrían resultar insuficientes para garantizar un nivel adecuado de seguridad frente a las acciones sísmicas esperadas. Por otra parte, otras circunstancias hacen que la vulnerabilidad de estos edificios parezca ser excesivamente elevada: (i) la ductilidad de los muros es limitada, (ii) los resultados experimentales disponibles son insuficientes y (iii) no existe experiencia acerca del comportamiento de estas construcciones para movimientos sísmicos de elevada severidad. Dada la preocupación que ha surgido en torno a este tipo de edificios, en Perú se han efectuado algunos ensayos, tanto sobre muros aislados como sobre conjuntos de muros y losas unidos; los resultados de estos ensayos se utilizan en este trabajo.Para llevar a cabo la investigación, se han seleccionado siete edificios representativos ubicados en su mayoría en la ciudad de Lima, que corresponde a la zona de mayor peligrosidad sísmica.Los períodos naturales han sido identificados a partir de trabajo de campo, determinándose también la resistencia del hormigón mediante pruebas esclerométricas. El estudio numérico de la vulnerabilidad de estas construcciones consiste en efectuar análisis estáticos no lineales ("push-over") y análisis dinámicos también no lineales, comparándose las conclusiones derivadas de ambos. Dada la elevada rigidez horizontal de los edificios, se ha tenido en cuenta la interacción entre el suelo y la estructura. El comportamiento estructural de los edificios se describe mediante modelos de fibras, éstos se implementan en el programa PERFORM-3D. Los estados límites de daño han sido definidos a partir de los resultados experimentales disponibles en Perú. Los acelerogramas considerados en los análisis dinámicos se pueden agrupar en tres categorías: (i) registros y acelerogramas sintéticos escalados al espectro de proyecto, (ii) registros impulsivos y (iii) dos movimientos sísmicos chilenos fuertes.Los resultados obtenidos indican que un alto porcentaje de los edificios existentes podrían experimentar graves daños ante los terremotos de proyecto, principalmente en las vigas de acoplamiento de las plantas superiores y en las partes bajas de los muros ubicados en la dirección débil. El ajuste entre las conclusiones de los análisis "push-over" y dinámicos es satisfactorio, resultando aquellos ligeramente más conservadores. A partir de los resultados de la investigación se concluye que un refuerzo ligero de las vigas de acoplamiento podría conducir a una notable mejora del comportamiento sismorresistente. Se proponen criterios preliminares de proyecto, como la recomendación de incluir una densidad mínima de muros en cada dirección.A partir del conocimiento proporcionado por este estudio sobre el comportamiento sismorresistente de este tipo de edificios, se identifican y analizan las necesidades futuras de investigación. Ésta se orienta a formular criterios finales de proyecto para estas construcciones.

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    Experimental study of friction dissipators for seismic protection of building structures  Open access

     Lopez Almansa, Francisco; de la Cruz, S. T.; Taylor, C.
    Earthquake engineering and engineering vibration
    Date of publication: 2011-12
    Journal article

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    This paper presents unidirectional shaking table tests of two reduced scale steel models of building frames; they have one and two floors, respectively. Such frames incorporate friction dissipators at every floor. The inputs are sine-dwells and artificial and registered earthquakes. This work belongs to a larger research project aiming to assess the seismic efficiency of friction dissipators by means of an integrated numerical and experimental approach. Inside this framework, the main objectives of these experiments are: (i) to collect a wide range of results useful to calibrate a numerical model derived inside the project, (ii) to contribute to clarify some of the most controversial issues about friction dissipators (behavior for inputs containing pulses, capacity to cut resonance peaks, introduction of high frequencies in the response, self-generated eccentricities), (iii) to better understand their dynamic behavior, (iv) to give an insight on the feasibility and reliability of using simple friction dissipators for seismic protection of building structures and (v) to characterize the hysteretic behavior of these devices. Most of these objectives are satisfactorily reached and relevant conclusions are stated.

    The final publication is available at www.springerlink.com

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  • Análisis de la fiabilidad del comportamiento sismo-resistente de los edificios de hormigón armado

     Bezzazi, Mohamed; Parrón Vera, Miguel Ángel; Rubio Cintas, Maria Dolores; Lopez Almansa, Francisco; El Ghoulbzouri, Abdelouafi; Khamlichi, Abdellatif
    Ingeniería civil (Madrid)
    Date of publication: 2011-04-01
    Journal article

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  • Seismic performance reliability analysis for reinforced concrete buildings

     El Ghoulbzouri, Abdelouafi; Khamlichi, Abdellatif; Bezzazi, Mohamed; Lopez Almansa, Francisco
    Journal of Civil Engineering and Construction Technology
    Date of publication: 2011-03-01
    Journal article

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  • Evaluating some reliability analysis methodologies in seismic design  Open access

     El Ghoulbzouri, Abdelouafi; Khamlichi, Abdellatif; Lopez Almansa, Francisco; Vera, M.A.P.; Rubio Cintas, Maria Dolores
    Journal of engineering and applied sciences
    Date of publication: 2011
    Journal article

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    Problem statement: Accounting for uncertainties that are present in geometric and material data of reinforced concrete buildings is performed in this study within the context of performance based seismic engineering design. Approach: Reliability of the expected performance state is assessed by using various methodologies based on finite element nonlinear static pushover analysis and specialized reliability software package. Reliability approaches that were considered included full coupling with an external finite element code and surface response based methods in conjunction with either first order reliability method or importance sampling method. Various types of probability distribution functions that model parameters uncertainties were introduced. Results: The probability of failure according to the used reliability analysis method and to the selected distribution of probabilities was obtained. Convergence analysis of the importance sampling method was performed. The required duration of analysis as function of the used reliability method was evaluated. Conclusion/Recommendations: It was found that reliability results are sensitive to the used reliability analysis method and to the selected distribution of probabilities. Durations of analysis for coupling methods were found to be higher than those associated to surface response based methods; one should however include time needed to derive these lasts. For the reinforced concrete building considered in this study, it was found that significant variations exist between all the considered reliability methodologies. The full coupled importance sampling method is recommended, but the first order reliability method applied on a surface response model can be used with good accuracy. Finally, the distributions of probabilities should be carefully identified since giving the mean and the standard deviation were found to be insufficient.

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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
    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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  • Theoretical and experimental analysis of dissipative buckling restrained braces

     Palazzo, G.; Lopez Almansa, Francisco; Cahis Carola, Xavier; Crisafulli, F.
    Date of publication: 2011-03-01
    Book

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  • Proposal of design energy spectra based on Turkish registers

     Yazgan, Ahmet Utku; Lopez Almansa, Francisco; Benavent Climent, A.
    Congreso Nacional de Ingeniería Sísmica
    Presentation of work at congresses

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  • Comportamiento sísmico de edificios con muros delgados de hormigón. Aplicación a zonas de alta sismicidad de Perú

     Lopez Almansa, Francisco; Gonzáles Fernández, Helbert
    Congreso Nacional de Ingeniería Sísmica
    Presentation's date: 2011-05-23
    Presentation of work at congresses

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  • Evaluación del comportamiento sismorresistente de edificios de hormigón con vigas planas

     Domínguez Santos, David Jesús; Lopez Almansa, Francisco; Benavent Climent, A.
    Congreso Nacional de Ingeniería Sísmica
    Presentation of work at congresses

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  • Propuesta de espectros de energía para proyecto sismorresistente basados en registros de Colombia  Open access

     Bravo González, Diego Andrés
    Defense's date: 2010-06-18
    Department of Structural Architecture, Universitat Politècnica de Catalunya
    Theses

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    Energy input spectra applicable to the seismic design of structures in moderate-to-high seismicity regions such as Colombia are proposed. They are derived from the bilinear envelope of individual spectra obtained for 144 ground motions recorded in Colombia. The spectra account for the increase of input energy due to the plastification of the structure in the short period region, through a new formula derived from extensive nonlinear analyses. The proposed energy input design spectra are compared with the provisions of the Colombian seismic code, and with those proposed for Japan, Iran and Greece. It is found that the proposed spectra are more demanding than the current Colombian seismic code, and that they are agree with those developed recently for six cities in Greece by applying a different approach. An empirical equation to estimate the portion of the seismic input energy that contributes to structural damage is also proposed.

  • Experimental testing of a new anti-seismic dissipator energy device based on the plasticity of metals

     Franco, J.M.; Cahis, X.; Gracia, L.; Lopez Almansa, Francisco
    Engineering structures
    Date of publication: 2010-09
    Journal article

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  • Effective Performance based Seismic Retrofit of Pre-code Reinforced Concrete Buildings

     El Haouzi, A.; Khamlichi, Abdellatif; Bezzazi, Mohamed; Lopez Almansa, Francisco
    Journal of Applied Sciences Research
    Date of publication: 2010-01-01
    Journal article

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  • Seismic performance reliability analysis of reinforced concrete buildings as parameterized by ductility

     El Ghoulbzouri, Abdelouafi; Khamlichi, Abdellatif; Bezzazi, Mohamed; Lopez Almansa, Francisco
    Journal of Basic and Applied Scientific Research
    Date of publication: 2010-01-01
    Journal article

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  • Experiments on Reinforced Brick Masonry Vaulted Light Roofs

     Lopez Almansa, Francisco; Roca Fabregat, Pedro; Sarrablo Moreno, Vicente; Cahis, X.; Miquel Canet, Juan
    ACI Structural Journal
    Date of publication: 2010-05
    Journal article

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  • Design energy input spectra for moderate-to-high seismicity regions based on Colombian earthquakes

     Benavent Climent, A.; Lopez Almansa, Francisco; Bravo González, D. A.
    Soil dynamics and earthquake engineering (1984)
    Date of publication: 2010-11
    Journal article

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  • Reinforced brick masonry light vaults: Semi-prefabrication, construction, testing and numerical modeling

     Lopez Almansa, Francisco; Sarrablo Moreno, Vicente; Lourenco, P. B.; Barros, J. A. O; Roca Fabregat, Pedro; da Porto, F.; Modena, C.
    Construction & building materials
    Date of publication: 2010-10
    Journal article

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  • Passive seismic energy dissipation applying fluid viscous damping technology: a state-of-the-art review

     Valdebenito, Galo; Aparicio Bengoechea, Angel Carlos; Álvarez Sereno, José de Jesús; Lopez Almansa, Francisco
    Congreso Chileno de Sismología e Ingeniería Antisísimica
    Presentation's date: 2010-05
    Presentation of work at congresses

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  • Seismic assessment of RC thin-wall buildings in Peru

     Lopez Almansa, Francisco; Gonzáles Fernández, Helbert
    European Conference on Earthquake Engineering
    Presentation's date: 2010-09-02
    Presentation of work at congresses

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  • Design energy spectra for Colombia and Turkey

     Lopez Almansa, Francisco; Yazgan, Ahmet Utku; Bravo González, Diego Andrés; Benavent Climent, Amadeu
    European Conference on Earthquake Engineering
    Presentation's date: 2010-07-30
    Presentation of work at congresses

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  • A low-tech dissipative buckling restrained brace. Design, analysis, production and testing

     Palazzo, G; Lopez Almansa, Francisco; Cahis, X; Crisafulli, F
    Engineering structures
    Date of publication: 2009-09
    Journal article

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  • Reliability Analysis for Seismic Performance Assessment of Concrete Reinforced Buildings

     Lopez Almansa, Francisco
    Australian Journal of Basic and Applied Sciences
    Date of publication: 2009-10-01
    Journal article

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  • CONTRIBUCIONES SISMOLÓGICAS, GEOFISICAS Y DE INGENIERIA A LA PREDICCION Y PREVENCION DEL RIESGO SISMICO

     Lopez Almansa, Francisco; Lana Pons, Francisco Javier; Serra De Larrocha, Carina; Osorio Gomez, Raul; Clapes Boixader, Jaime; Gonzalez Drigo, Jose Ramon; Martínez Santafé, Maria Dolors; Caselles Magallon, Jose Oriol; Perez Gracia, Maria de La Vega; Lantada Zarzosa, Nieves; Canas Torres, Jose Antonio; Pujades Beneit, Luis Gonzaga
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  • GEOFÍSICAI ENGINYERIA SÍSMICA

     Lopez Almansa, Francisco; Lana Pons, Francisco Javier; Serra De Larrocha, Carina; Osorio Gomez, Raul; Clapes Boixader, Jaime; Martínez Santafé, Maria Dolors; Pujades Beneit, Luis Gonzaga; Gonzalez Drigo, Jose Ramon; Caselles Magallon, Jose Oriol; Perez Gracia, Maria de La Vega; Canas Torres, Jose Antonio
    Participation in a competitive project

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  • Disipación pasiva de energía sísmica en estructuras de periodo largo aplicando tecnologías de amortiguamiento viscoso suplementario: una visión actualizada

     Valdebenito, Galo; Aparicio Bengoechea, Angel Carlos; Álvarez Sereno, José de Jesús; Lopez Almansa, Francisco
    Congreso Nacional de Ingeniería Sísmica
    Presentation of work at congresses

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  • Modelo numérico del comportamiento estructural de barras de pandeo restringido

     Castro Medina, Juan Carlos; Lopez Almansa, Francisco; Oller Martinez, Sergio Horacio
    Congreso de Métodos Numéricos en Ingeniería
    Presentation's date: 2009-07-01
    Presentation of work at congresses

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  • Seismic Risk Scenarios for Mérida, Venezuela

     Castillo, A; Pujades Beneit, Luis Gonzaga; Lopez Almansa, Francisco
    World Conference on Earthquake Engineering
    Presentation of work at congresses

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  • Design criteria for seismic retrofit of vulnerable concrete frames using energy dissipators

     Domínguez, D. J.; Lopez Almansa, Francisco; Benavent Climent, A.
    World Conference on Earthquake Engineering
    Presentation of work at congresses

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  • Tests of friction energy dissipators for seismic protection of buildings

     de la Cruz, S. T.; Lopez Almansa, Francisco; Taylor, C.
    World Conference on Earthquake Engineering
    Presentation of work at congresses

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  • Seismic Risk Reduction Measures of a Vulnerable Urban Informal Settlement in Mérida, Venezuela. Cost-Benefit Analysis

     Castillo, A.; Lopez Almansa, Francisco; Pujades Beneit, Luis Gonzaga
    World Conference on Earthquake Engineering
    Presentation of work at congresses

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  • Individual testing of dissipative buckling restrained braces

     Palazzo, G.; Lopez Almansa, Francisco; Cahis, X.; Crisafulli, F.
    World Conference on Earthquake Engineering
    Presentation of work at congresses

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  • Estudio experimental sobre barras de pandeo restringido como disipadores de energía

     Palazzo, G.; Lopez Almansa, Francisco; Cahis Carola, Xavier; Crisafulli, F.
    Congreso Nacional de Ingeniería Sísmica
    Presentation's date: 2007
    Presentation of work at congresses

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  • Estudio experimental sobre barras de pandeo restringido como disipadores de energía

     Lopez Almansa, Francisco
    Congreso Nacional de Ingeniería Sísmica
    Presentation's date: 2007-05-08
    Presentation of work at congresses

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  • Evaluación de la capacidad sismorresistente de estructuras de hormigón con vigas planas y propuesta de reacondicionamiento

     Lopez Almansa, Francisco
    Congreso Nacional de Ingeniería Sísmica
    Presentation's date: 2007-05-08
    Presentation of work at congresses

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  • Evaluation of the Seismic Vulnerability of Existing Buildings and Proposals for Retrofit Techniques Based on Energy Dissipation

     Lopez Almansa, Francisco
    10th World Conference on Seismic Isolation, Energy Dissipation and Active Control of Vibrations of Structures
    Presentation's date: 2007-05-28
    Presentation of work at congresses

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  • Estudio experimental sobre disipadores de energía basados en torsión de tubos de acero

     Lopez Almansa, Francisco
    Congreso Nacional de Ingeniería Sísmica
    Presentation's date: 2007-05-08
    Presentation of work at congresses

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  • Experimental Study of Prototype Buckling Restrained Braces

     Lopez Almansa, Francisco
    10th World Conference on Seismic Isolation, Energy Dissipation and Active Control of Vibrations of Structures
    Presentation's date: 2007-05-28
    Presentation of work at congresses

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  • Estudio experimental sobre disipadores de energía basados en torsión de tubos de acero

     Lopez Almansa, Francisco
    Congreso Nacional de Ingeniería Sísmica
    Presentation of work at congresses

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  • Numerical simulation of the seismic behavior of building structures equipped with friction energy dissipators

     Cruz, De La S T; Lopez Almansa, Francisco; Oller Martinez, Sergio Horacio
    Computers & structures
    Date of publication: 2007-01
    Journal article

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  • Limit analysis of reinforced masonry vaults

     Roca Fabregat, Pedro; Lopez Almansa, Francisco; Miquel Canet, Juan; Hanganu, Dan Alexandru
    Engineering structures
    Date of publication: 2007-03
    Journal article

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