Yielding and Ultimate Deformations of Wide and Deep Reinforced Concrete Beams

Current formulations proposed by Eurocode 8 part 3 for the inelastic deformations of existing reinforced concrete members are assessed separately for wide beams (WB) and conventional deep beams (DB). The current approach, based on a large experimental database of members, predicts larger ultimate chord rotation but lower chord rotation ductility for WB rather than for DB despite the similar curvature ductility, due to lower plastic hinge lengths in WB. However, if the data are disaggregated into DB and WB, predicted chord rotations are consistently conservative for DB and not conservative for WB if compared with experimental values, especially at ultimate deformation. Thus, plastic hinge length may be even greater for DB in comparison to WB. Therefore, some feasible corrections of the formulations for chord rotations are proposed, in order to reduce the bias and thus increase the robustness of the model for cross-section shape variability

Application for the automatic generation and insertion of plastic hinges in the SAP2000 environment

Software for the automatic generation of the files corresponding to the plastic hinges in order to be directly introduced in a structural model in SAP2000 by means of the “Interactive Database Editing”Gómez Martínez, F. (2017). Application for the automatic generation and insertion of plastic hinges in the SAP2000 environment. http://hdl.handle.net/10251/9094

La construcción parafrástica en las sentencias judiciales. Una propuesta de optimización del discurso

En este trabajo se analizan algunas de las inadecuaciones más comunes en la construc-ción parafrástica que aparecen en las sentencias judiciales y se realizan propuestas de optimización para un uso eficaz de esta operación textual que permita delimitar la in-formación en unidades legibles y comprensibles para el receptor de la sentencia. Con ello, se pretende no solo satisfacer un objetivo lingüístico, esto es, analizar el uso de este mecanismo textual en un género concreto; se persigue también, y muy especial-mente, mostrar cómo la acción del lingüista puede contribuir a mejorar los géneros discursivos propios de este ámbito profesional y, en definitiva, a facilitar tanto el quehacer discursivo de los profesionales del derecho como la comunicación entre es-tos y el ciudadano, receptor último y, a veces, olvidado de este proceso comunicativo

Influence of Different European Code Provisions for Capacity Design on the Seismic Performance of Reinforced Concrete Frames

Performance-based seismic codes ensure proper inelastic behaviour of reinforced concrete frames through capacity design, among others. This strategy relies not only on avoiding brittle failures and providing ductility to plastic hinges but also in their distribution within the frame aimed at a greater number of storeys involved in the eventual collapse mechanism. Although codes are generally in agreement to some basic principles in order to ensure capacity design, they show some discrepancies regarding the specific strategies. In this paper, capacity design provisions proposed by some European current codes—Eurocode 8, Italian NTC, and Spanish NCSE-02—are compared, and their effectiveness is discussed. The alternative formulation proposed by Italian code for “strong column–weak beam” turns out to be not suitable under specific circumstances, such as with large gravity loads or significant cantilever deformation in lower storeys. Regarding the value of axial load in columns to be considered for the calculation of shear and moment capacities, provisions in the three codes could eventually cause unconservative design for perimeter columns. The Spanish whole set of provisions is proved to not be effective due to their different fundamentals—they are based on overstrength instead of capacity. For all the three cases, some alternative procedures are suggested in this work

Influence of Different European Code Provisions for Capacity Design on the Seismic Performance of Reinforced Concrete Frames

[EN] Performance-based seismic codes ensure proper inelastic behaviour of reinforced concrete frames through capacity design, among others. This strategy relies not only on avoiding brittle failures and providing ductility to plastic hinges but also in their distribution within the frame aimed at a greater number of storeys involved in the eventual collapse mechanism. Although codes are generally in agreement to some basic principles in order to ensure capacity design, they show some discrepancies regarding the specific strategies. In this paper, capacity design provisions proposed by some European current codes-Eurocode 8, Italian NTC, and Spanish NCSE-02-are compared, and their effectiveness is discussed. The alternative formulation proposed by Italian code for "strong column-weak beam" turns out to be not suitable under specific circumstances, such as with large gravity loads or significant cantilever deformation in lower storeys. Regarding the value of axial load in columns to be considered for the calculation of shear and moment capacities, provisions in the three codes could eventually cause unconservative design for perimeter columns. The Spanish whole set of provisions is proved to not be effective due to their different fundamentals-they are based on overstrength instead of capacity. For all the three cases, some alternative procedures are suggested in this work.Gómez-Martínez, F.; Perez-Garcia, A. (2023). Influence of Different European Code Provisions for Capacity Design on the Seismic Performance of Reinforced Concrete Frames. Buildings. 13(8). https://doi.org/10.3390/buildings1308205113

Yielding and Ultimate Deformations of Wide and Deep Reinforced Concrete Beams

[EN] Current formulations proposed by Eurocode 8 part 3 for the inelastic deformations of existing reinforced concrete members are assessed separately for wide beams (WB) and conventional deep beams (DB). The current approach, based on a large experimental database of members, predicts larger ultimate chord rotation but lower chord rotation ductility for WB rather than for DB despite the similar curvature ductility, due to lower plastic hinge lengths in WB. However, if the data are disaggregated into DB and WB, predicted chord rotations are consistently conservative for DB and not conservative for WB if compared with experimental values, especially at ultimate deformation. Thus, plastic hinge length may be even greater for DB in comparison to WB. Therefore, some feasible corrections of the formulations for chord rotations are proposed, in order to reduce the bias and thus increase the robustness of the model for cross-section shape variability.Gómez-Martínez, F.; Perez-Garcia, A. (2022). Yielding and Ultimate Deformations of Wide and Deep Reinforced Concrete Beams. Buildings. 12(11). https://doi.org/10.3390/buildings12112015121

Dimensional analysis and experimental study of pressure drop and heat transfer for Na-Cl ice slurry in pipes

Over the last few years, many works have been developed to study the influence of some factors like the mass flow, pipe diameter or ice contents on the pressure drop characteristics and heat transfer process when using ice slurry as liquid secondary refrigerant. Nevertheless, most of these works present results of great scientific interest, but hardly applicable to different situations to those of test conditions and therefore they have a limited interest when approaching the design of practical ice slurry installations. Based on the dimensional analysis, the work reported in this paper try to determine which are the variables that explain the thermal and hydraulic behaviour of ice slurry, to fix the influence of these variables and to present the results so that they can be used as a tool of design for ice slurry applications. Experimental studies were performed to clarify the thermal and hydraulic characteristics of ice slurry with a 3% sodium chloride-water solution flowing in circular pipes. A number of experiments have been carried out to investigate the characteristics of flowing ice slurry for various pipes diameter, ice mass fraction, flow velocity and ice crystal size, and the non-dimensional values have been obtained from the pressure drop (via Fanning factor) and the heat transfer (via Nusselt number). Experimental data on friction factor are plotted on a Moody diagram. Experimental values of Nusselt number are plotted also versus Reynolds number and others parameters. Both data collection has been compared with other researcher’s results, showing the most cases a good level of agreement

Aspectos de integración multimodal en la prensa digital de tema jurídico y tema científico

The transition from written press to digital press provides news of greater multimodality, so that different semiotic modes concur in the construction of meaning. In this study, we want to analyse the way the relationship between images and text is realized in specialized digital press on legislative and juridical topics, and how this relationship contributes effectively to the multimodal cohesion of these news items, thus constructing complex multimodal entities. To this effect, we applied the intersemiotic model proposed by Martinec and Salway (2005) to analyse the image-text relation of 30 news items of the digital version of the newspaper ABC. With this model, we account for the logico-semantic and intersemiotic relationship between image and the text within the news.El paso de la prensa escrita a la prensa digital ha supuesto la posibilidad de dotar a las piezas informativas de una mayor multimodalidad, de manera que diversos modos semióticos concurren en la construcción del significado. En este trabajo queremos analizar en qué medida –y de qué manera– se establece la relación entre imágenes y textos en la prensa digital de especialidad de los ámbitos jurídico y científico; y si esta relación contribuye eficazmente en la cohesión multimodal de estas piezas informativas en tanto que complejos semánticos de carácter multimodal. Para ello, hemos aplicado el modelo intersemiótico propuesto por Martinec y Salway (2005) al análisis de la relación imagen-texto en 30 piezas informativas de la versión digital del periódico ABC. Con este modelo de análisis, queremos dar cuenta de esta relación en función del estatus que ocupan la imagen y el texto dentro de la pieza informativa en tanto que unidades semióticas en sí mismas y de la relación semántica entre ellas

Natural structures: strategies for geometric and morphological optimization

p. 893-906For centuries, architects and engineers have been searching the most efficient structural arrangements for their projects. Some of them have founded their proposals on the principle of biomimesis. The aim of their approach was to check how useful were 'for structural purposes' some geometrical patterns displayed by Nature on organic or inorganic bodies. Nature develops its structures in order to reach always optimal energetic solutions on a long term basis. The most usual arrangements are: pneus, shells, trees, webs and skeletons. All of them are controlled by four main factors: nature of forces, global form, local design and quality of material. Additional parameters, like pattern or material lightening, sometimes changes substantially the resulting geometry, and also some other general features as flexibility, integration, continuity, or self-straining are surrounding in most examples. This paper presents the achieved results on this topic by relevant authors of diverse fields: from the drawings of micro-organisms by the naturalist Häckel and the descriptive studies of the biologist Thompson, through the topological analysis of the patterns by the engineer Wester, the studies of natural lightweight structures by the architect F. Otto, to the final applications to light mega-structures by the engineers R. Le Ricolais or Buckminster Fuller.Pérez García, AJ.; Gómez Martínez, F. (2010). Natural structures: strategies for geometric and morphological optimization. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/695

FAST simplified vulnerability approach for seismic assessment of infilled RC MRF buildings and its application to the 2011 Lorca (Spain) earthquake

[EN] A simplified analytical method ("FAST") for the estimation of large-scale vulnerability of Reinforced Concrete (RC) Moment Resisting Frames with masonry infills is proposed and subsequently tested by using real damage scenario caused by the 2011 Lorca earthquake as a benchmark. FAST is a spectral-based approach that allows predicting the average non-structural Damage State expected for each class of building (defined by number of storeys, age of construction, infills ratio in plan and location) for a given demand level. It accounts for non-uniformity of infills in elevation, i.e. a reduction of infills ratio of the ground floor. FAST is based on: (i) the definition of approximated capacity curves of the infilled building, assuming that the RC frame is designed according to the corresponding seismic code; and on (ii) the assumption of "a priori" deformed shapes in accordance with the attainment of each non-structural damage state at 1st storey, estimated through experimental and numerical correlations. Two versions of FAST are proposed: a "simplified" approach aimed at the evaluation of uniformly infilled frames; and a "generalised" version which can account for any intermediate situation between uniformly infilled frames and pilotis frames (i.e. without infills at 1st storey). Also, some extensions of the method are highlighted. Aimed at testing FAST, the real damage scenario after the earthquake of Lorca (2011) is used as a benchmark, despite its impulsivity and directivity. In order to define the specific input parameters for the case study, information regarding ground motion, post-earthquake damage scenario and also building design practice must be collected. Hence, a detailed review of historical Spanish seismic codes and a critical analysis of current Spanish seismic code NCSE-02 in comparison with current reference performance-based codes such as Eurocode 8 are provided. Special emphasis is placed on provisions which can prevent a proper capacity design and that, in turn, can cause brittle failures or favour the interaction with infills. Also, the prescription of lower behaviour factor for wide-beam frames with respect to deep-beam frames -which is not present in most codes¿ is discussed; outcomes of several case studies suggest that such prescription is obsolete. Finally, FAST is applied to Lorca earthquake and predicted damage scenarios are obtained, considering different assumptions for input values. Results show proper agreement between predicted and real damages. Structural collapses were rarely observed, even though the PGA was three times higher than the typical acceleration of design, so FAST proves that masonry infills provided additional strength to RC frames.[ES] Se propone un método analítico simplificado ("FAST") para la estimación de la vulnerabilidad a gran escala de edificios porticados de hormigón armado con tabiquería de fábrica, posteriormente testeado mediante la adopción del escenario de daño real correspondiente al terremoto de Lorca de 2011 como patrón de comparación. FAST es un procedimiento espectral que permite predecir el nivel de daño no estructural medio esperado para cada clase de edificio (definido por su número de plantas, año de construcción, densidad de tabiquería en planta y localización geográfica), considerando un nivel de demanda dado. El método tiene en cuenta la irregularidad de la tabiquería en alzado, es decir, la posible reducción relativa de tabiquería en planta baja. FAST se basa en: (i) la definición de curvas de capacidad aproximadas para los edificios tabicados, asumiendo que la estructura de HA se ha proyectado según la norma sísmica correspondiente en cada caso; y en (ii) la asunción de deformadas "apriorísticas" coherentes con cada grado de daño (suponiendo que éste se alcanza siempre en planta baja), estimadas a través de correlaciones experimentales y numéricas. Se proponen dos versiones de FAST: una "simplificada" para la evaluación de edificios uniformemente tabicados en altura, y otra "generalizada", que es capaz de tener en cuenta cualquier situación intermedia entre el prototipo uniformemente tabicado y el de planta baja diáfana. Además, se proponen ciertas extensiones al método. A fin de validar FAST, se elige el escenario de daño real correspondiente al terremoto de Lorca (2011) como patrón de comparación, a pesar de su impulsividad y directividad. Para definir los parámetros de input correspondientes al caso de estudio, es necesario recopilar previamente la información concerniente a la señal sísmica, el escenario de daño y las características del parque construido. Por tanto, se lleva a cabo una revisión exhaustiva de las normas sísmicas históricas en España y un análisis crítico de la norma sísmica española actual NCSE-02 en comparación con otras normas actuales de referencia basadas en el desempeño, como el Eurocódigo 8, haciendo énfasis en las provisiones que no garantizan el diseño por capacidad y que por tanto pueden provocar mecanismos frágiles o favorecer la excesiva influencia de la tabiquería. Además, se discute sobre la restricción del coeficiente de ductilidad en estructuras de vigas planas, cuestión que no se refleja en otras normas. Los resultados obtenidos mediante análisis de casos de estudio muestran que dicha prescripción resulta obsoleta para normas actuales. Finalmente, FAST se aplica al caso del terremoto de Lorca, obteniéndose predicciones de daño medio para diferentes asunciones. Los resultados muestran una coincidencia aceptable entre la predicción y los daños reales. FAST confirma que la causa principal de la práctica ausencia de colapsos (ante un terremoto con PGA triple que la típica de proyecto) hay que buscarla en la contribución estructural de la tabiquería de fábrica.[CA] Es proposa un mètode analític simplificat ("FAST") per a l'estimació de la vulnerabilitat a gran escala d'edificis porticats de formigó armat amb envans de fàbrica. Posteriorment, el mètode ha estat testejat mitjançant l'adopció de l'escenari de dany real corresponent al terratrèmol de Lorca de 2011 com a patró de comparació. FAST és un procediment espectral que permet predir el nivell de dany no estructural mitjà esperat per a cada classe d'edifici (definit pel seu nombre de plantes, any de construcció, densitat d'envans en planta i localització geogràfica), considerant un determinat nivell de demanda. El mètode té en compte la irregularitat de la distribució de envans al llarg de les diferents plantes del edifici. Es a dir, es pot tenir en compte que, freqüentment, hi ha una menor quantitat de d'envans a la planta baixa. FAST es fonamenta en: (i) la definició de corbes de capacitat aproximades que tenen en compte no sols la estructura del edifici sinó també els envans i assumint que l'estructura de HA s'ha projectat segons la norma sísmica corresponent en cada cas; (ii) l'assumpció de deformades "apriorístiques" coherents amb cada grau de dany (suposant que aquest es dona sempre a la planta baixa) que han estat estimades a través de correlacions experimentals i numèriques. Es proposen dues versions de FAST: una "simplificada" per a l'avaluació d'edificis amb envans uniformement repartits per totes les plantes, i una altra "generalitzada", que és capaç de tenir en compte qualsevol situació intermèdia entre el prototip uniformement paredat i el de planta baixa diàfana. A més, es proposen certes extensions al mètode. Per tal de validar FAST, es tria l'escenari de dany real corresponent al terratrèmol de Lorca (2011) com a patró de comparació, malgrat la seva impulsivitat i directivitat. Per definir els paràmetres de entrada corresponents al cas d'estudi, cal recopilar prèviament la informació concernent al senyal sísmica, l'escenari de dany i les característiques del parc construït. Per tant, es porta a terme una revisió exhaustiva de les normes sísmiques històriques a Espanya i una anàlisi crítica de la norma sísmica espanyola actual (NCSE-02) comparant-la amb altres normes actuals de referència, com l'Eurocodi 8, fonamentat en el concepte d'acompliment. També es fa èmfasi a les provisions que no garanteixen el disseny per capacitat i que, per tant, poden provocar mecanismes de col·lapse fràgils o afavorir la interacció de la estructura amb els envans. A més, es discuteix sobre la restricció del coeficient de ductilitat de les estructures de bigues planes ja que es una qüestió que no aborden la majoria de les normes. Els resultats obtinguts mitjançant l'anàlisi de casos d'estudi mostren que aquesta restricció resulta obsoleta a les normes actuals. Finalment, FAST s'aplica al cas del terratrèmol de Lorca, obtenint prediccions de dany mitjà per a diferents combinacions del paràmetres de entrada. Els resultats mostren una coincidència acceptable entre la predicció i els danys reals. FAST confirma que la causa principal de la pràctica absència de col·lapses (davant un terratrèmol amb PGA triple que la típica de projecte) cal buscar-la en la contribució estructural dels envans.Gómez Martínez, F. (2015). FAST simplified vulnerability approach for seismic assessment of infilled RC MRF buildings and its application to the 2011 Lorca (Spain) earthquake [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/54780TESISPremios Extraordinarios de tesis doctorale