Ponències/Comunicacions de congressos
http://hdl.handle.net/2117/479
2016-10-28T21:50:00ZMultifractality and autoregressive processes of dry spell lengths in Europe: an approach to their complexity and predictability
http://hdl.handle.net/2117/82075
Multifractality and autoregressive processes of dry spell lengths in Europe: an approach to their complexity and predictability
Martínez Santafé, Maria Dolors; Lana Pons, Francisco Javier; Burgueño Rivero, August; Serra de Larrocha, Carina
2016-01-26T17:42:02ZMartínez Santafé, Maria DolorsLana Pons, Francisco JavierBurgueño Rivero, AugustSerra de Larrocha, CarinaFractal structure and predictability of distances between consecutive events: an analysis of three seismic aftershock sequences in Southern California
http://hdl.handle.net/2117/82074
Fractal structure and predictability of distances between consecutive events: an analysis of three seismic aftershock sequences in Southern California
Martínez Santafé, Maria Dolors; Lana Pons, Francisco Javier; Monterrubio Velasco, Marisol; Serra de Larrocha, Carina
2016-01-26T17:35:45ZMartínez Santafé, Maria DolorsLana Pons, Francisco JavierMonterrubio Velasco, MarisolSerra de Larrocha, CarinaFundamentos y ejemplos de aplicación del ensayo no destructivo de reflexión electromagnética mediante georradar en pavimentos asfálticos
http://hdl.handle.net/2117/26534
Fundamentos y ejemplos de aplicación del ensayo no destructivo de reflexión electromagnética mediante georradar en pavimentos asfálticos
Pedret Rodés, Josep; Pérez Gracia, María de la Vega; Valdés Vidal, Gonzalo A.
La prospección mediante Ground-Penetrating Radar (GPR) aplicada al estudio del pavimento de una carretera es un método no destructivo de análisis que, poco a poco, se ha ido implantando para la auscultación de carreteras. Este método, basado en la detección de discontinuidades electromagnéticas en el interior de un medio, permite registrar el tiempo de propagación de una señal electromagnética desde que se emite hasta que se recibe tras su reflexión en la discontinuidad. El registro de tiempos permite determinar espesores de las capas de un pavimento cuando se conoce la velocidad de propagación.También permite conocer algunas de sus condiciones físicas, generalmente contenido en huecos y grado de saturación. Además, los cambios de amplitud de la señal también permiten analizar características como el despegue entre capas. El conocimiento de estos factoreses fundamental para diseñar refuerzos de un pavimento asfáltico mediante métodos analíticos. En este estudio se muestran algunos ejemplos de aplicación con resultados obtenidos en vías de acceso a la ciudad de Barcelona.
2015-02-26T19:46:30ZPedret Rodés, JosepPérez Gracia, María de la VegaValdés Vidal, Gonzalo A.La prospección mediante Ground-Penetrating Radar (GPR) aplicada al estudio del pavimento de una carretera es un método no destructivo de análisis que, poco a poco, se ha ido implantando para la auscultación de carreteras. Este método, basado en la detección de discontinuidades electromagnéticas en el interior de un medio, permite registrar el tiempo de propagación de una señal electromagnética desde que se emite hasta que se recibe tras su reflexión en la discontinuidad. El registro de tiempos permite determinar espesores de las capas de un pavimento cuando se conoce la velocidad de propagación.También permite conocer algunas de sus condiciones físicas, generalmente contenido en huecos y grado de saturación. Además, los cambios de amplitud de la señal también permiten analizar características como el despegue entre capas. El conocimiento de estos factoreses fundamental para diseñar refuerzos de un pavimento asfáltico mediante métodos analíticos. En este estudio se muestran algunos ejemplos de aplicación con resultados obtenidos en vías de acceso a la ciudad de Barcelona.Applications of GPR in association with other non-destructive-testing methods in building assessment and in geological/geotechnical tasks. State of the art and open issues
http://hdl.handle.net/2117/26422
Applications of GPR in association with other non-destructive-testing methods in building assessment and in geological/geotechnical tasks. State of the art and open issues
Dimitriadis, Klisthenis; Pérez Gracia, María de la Vega
Geophysics is the study of the earth’s interior, using measurements based on physics principles. A part of this, geophysics is also used to explore the interior of construction materials of buildings and Monuments. The major advantage of this science is its absolute non-destructive character. However, despite
geophysics exist since the beginning of the 19th century the Ground Penetrating Radar (GPR) method is recently introduced in this domain, counting almost 50 years of active contribution. During these years, GPR was proved very effective in the building assessment. In the field of geotechnical tasks and especially in geological tasks, its efficiency was limited and strongly dependent on the site
conditions, mostly due to its limited in-depth penetration and relative target discrimination. Future research must be oriented to the improvement of these two major milestones, mostly into the antennas design and related instruments electronics design.
2015-02-19T09:49:46ZDimitriadis, KlisthenisPérez Gracia, María de la VegaGeophysics is the study of the earth’s interior, using measurements based on physics principles. A part of this, geophysics is also used to explore the interior of construction materials of buildings and Monuments. The major advantage of this science is its absolute non-destructive character. However, despite
geophysics exist since the beginning of the 19th century the Ground Penetrating Radar (GPR) method is recently introduced in this domain, counting almost 50 years of active contribution. During these years, GPR was proved very effective in the building assessment. In the field of geotechnical tasks and especially in geological tasks, its efficiency was limited and strongly dependent on the site
conditions, mostly due to its limited in-depth penetration and relative target discrimination. Future research must be oriented to the improvement of these two major milestones, mostly into the antennas design and related instruments electronics design.Energy-based design of a seismic protection system of timber platform frame buildings using energy dissipators
http://hdl.handle.net/2117/25158
Energy-based design of a seismic protection system of timber platform frame buildings using energy dissipators
López Almansa, Francisco; Segués Aguasca, Edgar; Rodríguez Cantalapiedra, Inma
This paper deals with a new seismic protection system for timber platform frame buildings, either for retrofit or for new construction. The system consists in connecting the timber frame to a steel framed structure that includes hysteretic energy dissipators designed to absorb most of the seismic input energy thus protecting the timber frame and the other steel members; alternatively, the system might contain other dissipative devices. The steel structure comprises horizontal beam-like elements, vertical column-like elements and chevron-like bracing members; the beam-like elements are steel belts embracing each slab of the building and the bracing members hold the energy dissipators. The steel structure is self-supporting,
i.e. the timber frame is not affected by horizontal actions and can be designed without accounting for any seismic provision; in turn, the steel members do not participate in the main carrying-loads
system. The timber-steel contact is even, smoothed and spread; it guarantees that the yielding of the dissipators is prior to any timber failure. This research belongs to a wider project aiming to promote the structural and constructional use of timber by improving the seismic capacity of wooden buildings; this research includes experiments and advanced numerical simulation aiming to derive accurate design criteria.
2015-01-07T19:30:35ZLópez Almansa, FranciscoSegués Aguasca, EdgarRodríguez Cantalapiedra, InmaThis paper deals with a new seismic protection system for timber platform frame buildings, either for retrofit or for new construction. The system consists in connecting the timber frame to a steel framed structure that includes hysteretic energy dissipators designed to absorb most of the seismic input energy thus protecting the timber frame and the other steel members; alternatively, the system might contain other dissipative devices. The steel structure comprises horizontal beam-like elements, vertical column-like elements and chevron-like bracing members; the beam-like elements are steel belts embracing each slab of the building and the bracing members hold the energy dissipators. The steel structure is self-supporting,
i.e. the timber frame is not affected by horizontal actions and can be designed without accounting for any seismic provision; in turn, the steel members do not participate in the main carrying-loads
system. The timber-steel contact is even, smoothed and spread; it guarantees that the yielding of the dissipators is prior to any timber failure. This research belongs to a wider project aiming to promote the structural and constructional use of timber by improving the seismic capacity of wooden buildings; this research includes experiments and advanced numerical simulation aiming to derive accurate design criteria.Seismic protection of timber platform frame building structures with hysteretic energy dissipators: feasibility study
http://hdl.handle.net/2117/25157
Seismic protection of timber platform frame building structures with hysteretic energy dissipators: feasibility study
Segués Aguasca, Edgar; López Almansa, Francisco; Rodríguez Cantalapiedra, Inma
This paper describes a feasibility study of new hysteretic energy dissipators for seismic protection of timber platform frame buildings, either for retrofit or for new construction. The system consists in connecting the timber frame to a steel framed structure that includes the new energy dissipators devices, designed to absorb most of the seismic input energy thus protecting the timber frame and the other steel members; alternatively, the system might contain other dissipative devices. The steel structure comprises horizontal beam-like elements, vertical column like elements and chevron-like bracing members; the beam-like elements are steel belts embracing each slab of the building and the bracing members hold the energy dissipators. The steel structure is self-supporting, i.e. the timber frame is not affected by horizontal actions and can be designed without accounting for any seismic provision; in turn, the steel members do not participate in the main carrying-loads system. The timber-steel contact is even, smoothed and spread; it guarantees that the yielding of the dissipators is prior to any timber failure. This research belongs to a wider project aiming to promote the structural and constructional use of timber in seismic regions; this research includes experiments and advanced numerical simulation aiming to derive accurate design criteria. Comparison with unprotected buildings and other earthquake-resistant solutions is in progress.
2015-01-07T17:58:07ZSegués Aguasca, EdgarLópez Almansa, FranciscoRodríguez Cantalapiedra, InmaThis paper describes a feasibility study of new hysteretic energy dissipators for seismic protection of timber platform frame buildings, either for retrofit or for new construction. The system consists in connecting the timber frame to a steel framed structure that includes the new energy dissipators devices, designed to absorb most of the seismic input energy thus protecting the timber frame and the other steel members; alternatively, the system might contain other dissipative devices. The steel structure comprises horizontal beam-like elements, vertical column like elements and chevron-like bracing members; the beam-like elements are steel belts embracing each slab of the building and the bracing members hold the energy dissipators. The steel structure is self-supporting, i.e. the timber frame is not affected by horizontal actions and can be designed without accounting for any seismic provision; in turn, the steel members do not participate in the main carrying-loads system. The timber-steel contact is even, smoothed and spread; it guarantees that the yielding of the dissipators is prior to any timber failure. This research belongs to a wider project aiming to promote the structural and constructional use of timber in seismic regions; this research includes experiments and advanced numerical simulation aiming to derive accurate design criteria. Comparison with unprotected buildings and other earthquake-resistant solutions is in progress.Probabilistic assessment of the seismic damage in reinforced concrete buildings
http://hdl.handle.net/2117/22401
Probabilistic assessment of the seismic damage in reinforced concrete buildings
Barbat Barbat, Horia Alejandro; Vargas Alzate, Yeudy Felipe; Pujades Beneit, Lluís; Hurtado Gomez, Jorge Eduardo
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.
2014-03-26T18:48:44ZBarbat Barbat, Horia AlejandroVargas Alzate, Yeudy FelipePujades Beneit, LluísHurtado Gomez, Jorge EduardoThe 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.Risk assessment of reinforced concrete buildings considering the earthquake directionality effects
http://hdl.handle.net/2117/22398
Risk assessment of reinforced concrete buildings considering the earthquake directionality effects
Vargas Alzate, Yeudy Felipe; Pujades Beneit, Lluís; Barbat Barbat, Horia Alejandro; Hurtado Gomez, Jorge Eduardo
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.
2014-03-26T18:34:23ZVargas Alzate, Yeudy FelipePujades Beneit, LluísBarbat Barbat, Horia AlejandroHurtado Gomez, Jorge EduardoIn 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
http://hdl.handle.net/2117/22397
Análisis comparativo del peligro sísmico de Barcelona
Aguilar Meléndez, Armando; Pujades Beneit, Lluís; Ordaz, Mario G.; Barbat Barbat, Horia Alejandro; Lantada Zarzosa, Maria de Las Nieves; García Elías, Alejandro; Campos, Amelia
2014-03-26T18:25:30ZAguilar Meléndez, ArmandoPujades Beneit, LluísOrdaz, Mario G.Barbat Barbat, Horia AlejandroLantada Zarzosa, Maria de Las NievesGarcía Elías, AlejandroCampos, AmeliaEvaluación probabilista del riesgo sísmico de edificios de hormigón armado con base en la degradación de la rigidez
http://hdl.handle.net/2117/21205
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, Lluís; Hurtado Gomez, Jorge Eduardo
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.
2014-01-09T19:00:20ZBarbat Barbat, Horia AlejandroVargas Alzate, Yeudy FelipePujades Beneit, LluísHurtado Gomez, Jorge EduardoThe 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.