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

     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.

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

     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.

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

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

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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.

  • 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
    Theses

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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.

  • 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
    Participation in a competitive project

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  • A numerical model of the structural behavior of buckling-restrained braces

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

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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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  • 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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  • 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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  • Evaluating some Reliability Analysis Methodologies in Seismic Design

     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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  • 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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  • 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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  • Experimental study of friction dissipators for seismic protection of building structures

     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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  • 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.

  • 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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  • Seismic risk analysis of urban non-engineered buildings: Application to an informal settlement in Mérida, Venezuela

     Castillo, A.; Lopez Almansa, Francisco; Pujades Beneit, Luis Gonzaga
    Natural hazards
    Date of publication: 2011-11
    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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  • 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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  • 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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  • 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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  • 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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  • 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.

  • 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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  • 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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  • 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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  • 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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  • An innovative isolation device for aseismic design  Open access  awarded activity

     Ismail Abdelkareem Moustafa, Mohammed
    Defense's date: 2009-11-09
    Department of Geotechnical Engineering and Geo-Sciences, Universitat Politècnica de Catalunya
    Theses

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    Basado en la idea de reducir la demanda sísmica en lugar de aumentar la capacidad resistente de las estructuras, el aislamiento sísmico es un método simple para mitigar o reducir los posibles daños producidos por los terremotos. La correcta aplicación de esta tecnología conduce a un mejor comportamiento de las estructuras, que sigue siendo esencialmente elástico durante los terremotos de gran magnitud. El núcleo de esta tecnología es el aislador. La mayoría de los aisladores sísmicos disponibles en la actualidad siguen teniendo limitaciones prácticas que impiden que funcionen según lo previsto e imponen restricciones a su uso efectivo y al nivel de protección proporcionado. En esta Tesis, se presenta un aislador sísmico avanzado llamado "roll-n-cage (RNC)". Se propone investigar su eficiencia a través de simulación numérica, en un intento de crear un sistema de aislamiento sísmico práctico, efectivo y económico, que tiene por objeto resolver los principales inconvenientes de los actuales sistemas de aislamiento sísmico, manteniendo sus principales ventajas. Este aislador incorpora aislamiento, disipación de energía, amortiguamiento y capacidad de fuerza recuperadora en una sola unidad. Además, ofrece una resistencia al viento significativa y una amplia gama de flexibilidad horizontal, por lo que es adecuado para proteger las estructuras de masa ligera, moderada y grande, así como para proteger equipos sensibles, hardware y / o antigüedades alojados en edificios. Por otra parte, las cuestiones relativas a la viabilidad, los costes de construcción y la disponibilidad de materiales, reducción o prevención de las respuestas de torsión y la resistencia a la elevación son abordados a fondo durante el diseño del aislador RNC. El aislador RNC propuesto es descrito en profundidad y sus principios de funcionamiento son presentados en detalle. La caracterización mecánica del dispositivo se ha llevado a cabo por medio de un código computacional sofisticado que simula la respuesta de los dispositivos como si estuvieran sujetos a una máquina de pruebas reales. A través de este esquema, se consigue analizar numéricamente el comportamiento del aislador RNC bajo el efecto simultáneo de cargas horizontales y verticales, como se da típicamente en situaciones prácticas. Además, se presenta una descripción matemática de las principales características asociadas a la rodadura de los aisladores RNC. Asimismo se obtiene un modelo matemático para describir en una forma razonable y manejable la relación fuerza desplazamiento exhibida por el aislador de RNC. Para evaluar la viabilidad del aislador RNC y para comprobar su capacidad para proteger los sistemas estructurales y no estructurales de los riesgos sísmicos, el dispositivo se implementa numéricamente en una variedad de estructuras con masas ligeras y grandes, además de en equipos sensibles alojados en los pisos superiores de dichas estructuras. Para extraer conclusiones de carácter relativamente general sobre el funcionamiento del aislador RNC, se estudia una amplia gama de terremotos y de características y propiedades de los aisladores y de las estructuras.Los resultados numéricos revelan que el aislador RNC propuesto puede reducir la respuesta sísmica frente a un amplio rango de excitaciones sísmicas, mientras que exhibe un rendimiento robusto para una gran variedad de estructuras. La Tesis incluye como apéndice un estudio en profundidad sobre el modelo de histéresis de Bouc-Wen. El estudio contiene una revisión de los primeros y últimos avances y aplicaciones de este modelo, que es ampliamente utilizado en la descripción de fenómenos de histéresis en las estructuras.

    Based on the concept of reducing seismic demand rather than increasing the earthquake resistant capacity of structures, seismic isolation is a surprisingly simple approach to mitigate or reduce earthquake damage potential. Proper application of this complex technology leads to better performing structures that will remain essentially elastic during large earthquakes. The core of this technology is the isolator. Most currently available seismic isolators still have practical limitations causing them not to function as anticipated and impose restrictions to their proper use and to the provided protection level. In this dissertation, an advanced rolling-based seismic isolator, named roll-n-cage (RNC) isolator, is proposed and investigated via numerical simulation as an attempt to create a practical, effective, and economic seismic isolation system that aims to fix the main drawbacks of the current seismic isolation systems while keeping their main advantages. This isolator incorporates isolation, energy dissipation, buffer and restoring force mechanisms in a single unit. Further, it offers a significant wind resistance and a great range of horizontal flexibility making it ideal to protect light, moderate and heavy mass structures as well as precious housed motion-sensitive equipment, hardware and/or antiquities. Moreover, issues related to practicality, construction costs and material availability, reducing or preventing torsional responses and uplift resistance are thoroughly addressed during the RNC bearing design.The proposed RNC isolator is deeply described and its principles of operation are extensively highlighted. The mechanical characterization of the device has been carried out by means of a sophisticated computer code in a machine-like environment, which accurately simulates the response of the device subjected to a real testing machine. Through this machine-like environment, a general scheme is followed to numerically examine the behavior of the RNC isolator under simultaneous horizontal and vertical loads as in typical practical situations. Further, a mathematical description of the main features associated to rolling of the RNC isolator is presented. An input-output mathematical model is obtained to describe in a reasonable and manageable form the force-displacement relationship exhibited by the RNC isolator.To assess the feasibility of the RNC isolator and to check its ability to protect structural and nonstructural systems from seismic hazards, it is numerically implemented to a variety of structures having light to heavy masses, in addition to motion-sensitive equipment housed in upper building floors. Further, and to draw relatively general conclusions about the performance of the RNC isolator, a wide range of ground motions, isolator characteristics and structural properties is considered. The numerical results reveal that the proposed RNC isolation bearing can mitigate the seismic responses under a variety of ground motion excitations while exhibiting robust performance for a wide range of structures. The dissertation is appended with an in-depth survey, that contains a review of the past, recent developments and implementations of the versatile Bouc-Wen model of smooth hysteresis, which is used extensively in modeling the hysteresis phenomenon in the dynamically excited nonlinear structures. This survey is the first of its kind about the model since its origination more than 30 years ago. The objective is to present some of the popular approaches that have utilized and/or developed that model to capture the hysteretic behavior offered by a variety of nonlinear systems. Then, the evaluation of their results and contributions (if any) is carried out to highlight their assets and limitations and to identify future directions in this research area.

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

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

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