Articles de revistahttp://hdl.handle.net/2117/23682024-03-19T13:06:20Z2024-03-19T13:06:20ZActive control implementation in cable-stayed bridges for quasi-static loading patternsCrusells Girona, MiquelAparicio Bengoechea, Ángel Carloshttp://hdl.handle.net/2117/885792021-05-20T04:13:29Z2016-07-06T16:36:50ZActive control implementation in cable-stayed bridges for quasi-static loading patterns
Crusells Girona, Miquel; Aparicio Bengoechea, Ángel Carlos
The following paper deals with active control implementation in cable-stayed bridges. Recent developments in structural active control of cable-stayed bridges are focused on the adaptability to dynamic effects produced by earthquakes or extreme winds (El Ouni et al., 2012; Pakos and Wojcicki, 2014; Domaneschi et al., 2015a,b). Nevertheless, no attention has been paid to the static or quasi-static case. As stated by Housner et al. (1996), Song et al. (2006) or Gilewski and Al Sabouni-Zawadzka (2015), active control could also be useful to diminish fatigue in the day-to-day performance of this type of bridges by decreasing stresses adaptively. Indeed, the following paper shows that excitation periods produced by traffic loads and natural periods of vibration of this type of bridges are sufficiently distant one another so as to conclude that a quasi-static analysis can be performed. Filling this gap, the following paper proposes a structural analysis procedure to include active control systems in the design process of cable stayed bridges, as well as suggestions which ought to be considered in order to include these cases into codes. The results of the paper, studying both non-cumulative and cumulative load cases, show a reduction in unbalanced bending moment referred to the Neutral Moment State of around 25%, depending on the load case. As a result, active control systems compensating quasi-static loading patterns can certainly help engineers optimise the design of these emblematic structures.
2016-07-06T16:36:50ZCrusells Girona, MiquelAparicio Bengoechea, Ángel CarlosThe following paper deals with active control implementation in cable-stayed bridges. Recent developments in structural active control of cable-stayed bridges are focused on the adaptability to dynamic effects produced by earthquakes or extreme winds (El Ouni et al., 2012; Pakos and Wojcicki, 2014; Domaneschi et al., 2015a,b). Nevertheless, no attention has been paid to the static or quasi-static case. As stated by Housner et al. (1996), Song et al. (2006) or Gilewski and Al Sabouni-Zawadzka (2015), active control could also be useful to diminish fatigue in the day-to-day performance of this type of bridges by decreasing stresses adaptively. Indeed, the following paper shows that excitation periods produced by traffic loads and natural periods of vibration of this type of bridges are sufficiently distant one another so as to conclude that a quasi-static analysis can be performed. Filling this gap, the following paper proposes a structural analysis procedure to include active control systems in the design process of cable stayed bridges, as well as suggestions which ought to be considered in order to include these cases into codes. The results of the paper, studying both non-cumulative and cumulative load cases, show a reduction in unbalanced bending moment referred to the Neutral Moment State of around 25%, depending on the load case. As a result, active control systems compensating quasi-static loading patterns can certainly help engineers optimise the design of these emblematic structures.Evaluation of natural colonisation of cementitious materials: Effect of bioreceptivity and environmental conditionsManso Blanco, SandraCalvo-Torrás, María AngelesDe Belie, NeleSegura Pérez, IgnacioAguado de Cea, Antoniohttp://hdl.handle.net/2117/850452022-10-09T03:26:03Z2016-04-01T10:33:35ZEvaluation of natural colonisation of cementitious materials: Effect of bioreceptivity and environmental conditions
Manso Blanco, Sandra; Calvo-Torrás, María Angeles; De Belie, Nele; Segura Pérez, Ignacio; Aguado de Cea, Antonio
Incorporation of living organisms, such as photosynthetic organisms, on the structure envelope has become a priority in the area of architecture and construction due to aesthetical, economic and ecological advantages. Important research efforts are made to achieve further improvements, such as for the development of cementitious materials with an enhanced bioreceptivity to stimulate biological growth. Previously, the study of the bioreceptivity of cementitious materials has been carried out mainly under laboratory conditions although field-scale experiments may present different results.
This work aims at analysing the colonisation of cementitious materials with different levels of bioreceptivity by placing them in three different environmental conditions. Specimens did not present visual colonisation, which indicates that environmental conditions have a greater impact than intrinsic properties of the material at this stage. Therefore, it appears that in addition to an optimized bioreceptivity of the concrete (i.e., composition, porosity and roughness), extra measures are indispensable for a rapid development of biological growth on concrete surfaces. An analysis of the colonisation in terms of genus and quantity of the most representative microorganisms found on the specimens for each location was carried out and related to weather conditions, such as monthly average temperature and total precipitation, and air quality in terms of NOx, SO2, CO and O3.
OPC-based specimens presented a higher colonisation regarding both biodiversity and quantity. However, results obtained in a previous experimental programme under laboratory conditions suggested a higher suitability of Magnesium Phosphate Cement-based (MPC-based) specimens for algal growth. Consequently, carefully considering the environment and the relationships between the different organisms present in an environment is vital for successfully using a cementitious material as a substrate for biological growth.
2016-04-01T10:33:35ZManso Blanco, SandraCalvo-Torrás, María AngelesDe Belie, NeleSegura Pérez, IgnacioAguado de Cea, AntonioIncorporation of living organisms, such as photosynthetic organisms, on the structure envelope has become a priority in the area of architecture and construction due to aesthetical, economic and ecological advantages. Important research efforts are made to achieve further improvements, such as for the development of cementitious materials with an enhanced bioreceptivity to stimulate biological growth. Previously, the study of the bioreceptivity of cementitious materials has been carried out mainly under laboratory conditions although field-scale experiments may present different results.
This work aims at analysing the colonisation of cementitious materials with different levels of bioreceptivity by placing them in three different environmental conditions. Specimens did not present visual colonisation, which indicates that environmental conditions have a greater impact than intrinsic properties of the material at this stage. Therefore, it appears that in addition to an optimized bioreceptivity of the concrete (i.e., composition, porosity and roughness), extra measures are indispensable for a rapid development of biological growth on concrete surfaces. An analysis of the colonisation in terms of genus and quantity of the most representative microorganisms found on the specimens for each location was carried out and related to weather conditions, such as monthly average temperature and total precipitation, and air quality in terms of NOx, SO2, CO and O3.
OPC-based specimens presented a higher colonisation regarding both biodiversity and quantity. However, results obtained in a previous experimental programme under laboratory conditions suggested a higher suitability of Magnesium Phosphate Cement-based (MPC-based) specimens for algal growth. Consequently, carefully considering the environment and the relationships between the different organisms present in an environment is vital for successfully using a cementitious material as a substrate for biological growth.Sand-cement concrete in the century-old Camarasa damBlanco Álvarez, AnaSegura Pérez, IgnacioPialarissi Cavalaro, Sergio HenriqueChinchón Payá, ServandoAguado de Cea, Antoniohttp://hdl.handle.net/2117/841852022-10-09T09:26:22Z2016-03-10T20:18:06ZSand-cement concrete in the century-old Camarasa dam
Blanco Álvarez, Ana; Segura Pérez, Ignacio; Pialarissi Cavalaro, Sergio Henrique; Chinchón Payá, Servando; Aguado de Cea, Antonio
Sand-cement emerged in the early twentieth century as an alternative binder in infrastructures that required a significant amount of concrete volume in order to reduce the costs associated with portland cement. This binder was first used in the United States in several dams before being applied in Camarasa Dam in Spain. Nearly a century after its construction, the dam exhibits degradation phenomena in the downstream face, manifested by losses of mass. The present study aims at assessing the state of the sand-cement concrete in Camarasa Dam and evaluate whether the degradation observed could affect the safety and functionality of the 95-year-old dam. For that, the state of the art on sand-cement is reviewed and an experimental program of physical, mechanical, and chemical tests is performed on samples from the dam. The results reveal that the degradation phenomena may be attributed to physical causes and a general degradation of the concrete properties is discarded as well as any effect on the safety and functionality of the dam.
2016-03-10T20:18:06ZBlanco Álvarez, AnaSegura Pérez, IgnacioPialarissi Cavalaro, Sergio HenriqueChinchón Payá, ServandoAguado de Cea, AntonioSand-cement emerged in the early twentieth century as an alternative binder in infrastructures that required a significant amount of concrete volume in order to reduce the costs associated with portland cement. This binder was first used in the United States in several dams before being applied in Camarasa Dam in Spain. Nearly a century after its construction, the dam exhibits degradation phenomena in the downstream face, manifested by losses of mass. The present study aims at assessing the state of the sand-cement concrete in Camarasa Dam and evaluate whether the degradation observed could affect the safety and functionality of the 95-year-old dam. For that, the state of the art on sand-cement is reviewed and an experimental program of physical, mechanical, and chemical tests is performed on samples from the dam. The results reveal that the degradation phenomena may be attributed to physical causes and a general degradation of the concrete properties is discarded as well as any effect on the safety and functionality of the dam.Structural health monitoring in incrementally launched steel bridges: patch loading phenomena modelingChacón Flores, Rolando AntonioZorrilla Martínez, Rubénhttp://hdl.handle.net/2117/782022021-12-12T02:17:00Z2015-10-23T14:12:46ZStructural health monitoring in incrementally launched steel bridges: patch loading phenomena modeling
Chacón Flores, Rolando Antonio; Zorrilla Martínez, Rubén
In this paper, a realistic nonlinear 3D simulation of an incrementally launched steel bridge girder is presented. The numerical simulation accounts for three sources of nonlinearity: geometry, material and boundary conditions. For the sake of depicting the capabilities of the presented numerical model in structural verifications, the study is focused on the patch loading field, a structurally complex phenomenon. Patch loading (or concentrated loading) is one of the most typically encountered structural verifications on incrementally launched steel 1-girders. The presented realistic simulation is based upon an experimentally calibrated numerical model and may provide relevant information at both design and construction stages. For the former, the predictive capabilities of the model for inferring the potential failure due to patch loading are depicted. For the latter, the results obtained are displayed in a way that may be useful for planning a Structural Health Monitoring (SHM) deployment aimed at controlling the patch loading-related phenomena in incrementally launched steel plate girders.
2015-10-23T14:12:46ZChacón Flores, Rolando AntonioZorrilla Martínez, RubénIn this paper, a realistic nonlinear 3D simulation of an incrementally launched steel bridge girder is presented. The numerical simulation accounts for three sources of nonlinearity: geometry, material and boundary conditions. For the sake of depicting the capabilities of the presented numerical model in structural verifications, the study is focused on the patch loading field, a structurally complex phenomenon. Patch loading (or concentrated loading) is one of the most typically encountered structural verifications on incrementally launched steel 1-girders. The presented realistic simulation is based upon an experimentally calibrated numerical model and may provide relevant information at both design and construction stages. For the former, the predictive capabilities of the model for inferring the potential failure due to patch loading are depicted. For the latter, the results obtained are displayed in a way that may be useful for planning a Structural Health Monitoring (SHM) deployment aimed at controlling the patch loading-related phenomena in incrementally launched steel plate girders.Percepción social de los técnicos del sector de la construcción en España : Influencia de la crisis económicaPlanas Rodríguez, CarlaCuerva Contreras, EvaAlquézar Claramunt, ÒscarAlavedra Ribot, Perehttp://hdl.handle.net/2117/775802022-09-18T06:03:19Z2015-10-13T10:05:05ZPercepción social de los técnicos del sector de la construcción en España : Influencia de la crisis económica
Planas Rodríguez, Carla; Cuerva Contreras, Eva; Alquézar Claramunt, Òscar; Alavedra Ribot, Pere
En el presente artículo se analiza el papel social que desempeñan los técnicos de la construcción en España, cuestionando si la crisis económica ha modificado negativamente la percepción que la ciudadanía tiene de ellos. La importante caída salarial y de número de visados de este colectivo desde 2009 resulta muy preocupante, y hace necesario fomentar una visión social positiva del mismo que favorezca su recuperación.
En el artículo se analiza, en primer lugar, cómo el entorno económico actual ha afectado a la percepción social de las profesiones del sector de la construcción, señalando aquellos puntos que podrían incidir de forma negativa en ella. Asimismo, se aporta la percepción que tienen sus profesionales del factor social en estos momentos de crisis. Este análisis permite concluir que, a pesar de que la ingeniería mejora la calidad de vida de los ciudadanos, el anonimato de las obras y trabajos realizados ocasiona una relativa invisibilidad social de sus profesionales.
Finalmente, se plantean alternativas para mejorar la situación existente. Las ingenierías del ámbito de la construcción deberán diversificar sus campos de acción hacia mercados más próximos a la sociedad, como la sostenibilidad, el medio ambiente o la energía. Será necesario que la ingeniería aporte rigor y método a estos estudios, haciendo un mayor uso de herramientas matemáticas, termodinámicas y de simulación.
Por último, es necesario también establecer metodologías o indicadores que permitan analizar con mayor rigor la percepción pública del sector. De este modo se conseguirá que el colectivo tenga los medios necesarios para hacer una mejor difusión de su trabajo, favoreciendo su valoración por parte de la ciudadanía e incrementando así las expectativas laborales de sus profesionales y con ello el número de jóvenes que escogen dichos estudios.
2015-10-13T10:05:05ZPlanas Rodríguez, CarlaCuerva Contreras, EvaAlquézar Claramunt, ÒscarAlavedra Ribot, PereEn el presente artículo se analiza el papel social que desempeñan los técnicos de la construcción en España, cuestionando si la crisis económica ha modificado negativamente la percepción que la ciudadanía tiene de ellos. La importante caída salarial y de número de visados de este colectivo desde 2009 resulta muy preocupante, y hace necesario fomentar una visión social positiva del mismo que favorezca su recuperación.
En el artículo se analiza, en primer lugar, cómo el entorno económico actual ha afectado a la percepción social de las profesiones del sector de la construcción, señalando aquellos puntos que podrían incidir de forma negativa en ella. Asimismo, se aporta la percepción que tienen sus profesionales del factor social en estos momentos de crisis. Este análisis permite concluir que, a pesar de que la ingeniería mejora la calidad de vida de los ciudadanos, el anonimato de las obras y trabajos realizados ocasiona una relativa invisibilidad social de sus profesionales.
Finalmente, se plantean alternativas para mejorar la situación existente. Las ingenierías del ámbito de la construcción deberán diversificar sus campos de acción hacia mercados más próximos a la sociedad, como la sostenibilidad, el medio ambiente o la energía. Será necesario que la ingeniería aporte rigor y método a estos estudios, haciendo un mayor uso de herramientas matemáticas, termodinámicas y de simulación.
Por último, es necesario también establecer metodologías o indicadores que permitan analizar con mayor rigor la percepción pública del sector. De este modo se conseguirá que el colectivo tenga los medios necesarios para hacer una mejor difusión de su trabajo, favoreciendo su valoración por parte de la ciudadanía e incrementando así las expectativas laborales de sus profesionales y con ello el número de jóvenes que escogen dichos estudios.Influencia del contenido de finos en la respuesta estructural a flexión y cortante de vigas de hormigón armadoSantos Ferreira, Denise CarinaOller Ibars, EvaBairán García, Jesús MiguelMarí Bernat, Antonio RicardoCarrascon, Sergiohttp://hdl.handle.net/2117/770962023-09-10T11:26:35Z2015-09-25T12:13:48ZInfluencia del contenido de finos en la respuesta estructural a flexión y cortante de vigas de hormigón armado
Santos Ferreira, Denise Carina; Oller Ibars, Eva; Bairán García, Jesús Miguel; Marí Bernat, Antonio Ricardo; Carrascon, Sergio
Este artículo presenta un estudio experimental sobre el comportamiento a flexión y cortante de vigas de hormigón armado con un contenido de finos (275 kg/m3) superior al límite permitido por la Instrucción EHE-08 (175 kg/m3). En el rango estudiado, el contenido de finos apenas afectó a la respuesta a flexión. La resistencia a cortante de vigas con alto contenido de finos fue menor que la de las vigas de hormigón convencional, en especial para las vigas con cuantía alta de armadura longitudinal y con armadura de cortante, con una reducción de hasta el 23 % en la carga última. Esta reducción se considera debida a la disminución de propiedades mecánicas del hormigón que afecta especialmente al cortante resistido por fricción en la fisura. Por último, los ensayos realizados han permitido verificar un modelo numérico de análisis no lineal evolutivo para predecir el comportamiento de estructuras de hormigón con distintos contenidos de finos.; This paper presents an experimental study on the flexural and shear behavior of reinforced concrete beams with a fines
content (275 kg/m3) higher than the limit value allowed by the Spanish Concrete Code EHE-08 (175 kg/m3). In the studied
range, the fines content scarcely affected the flexural response. The shear strength of the beams with a high content of fines was lower than that of the beams cast with conventional concrete, especially for those with a high longitudinal internal reinforcement ratio and with transversal stirrups, where the reduction of the ultimate load was up to 23 %. Such a reduction is considered due to the reduction of mechanical properties of concrete and that of the aggregate interlock along the crack length. Finally, the experimental results have allowed verifying a numerical model for the non-linear analysis of RC members to accurately predict the influence of the amount of fine aggregate on the structural response.
2015-09-25T12:13:48ZSantos Ferreira, Denise CarinaOller Ibars, EvaBairán García, Jesús MiguelMarí Bernat, Antonio RicardoCarrascon, SergioEste artículo presenta un estudio experimental sobre el comportamiento a flexión y cortante de vigas de hormigón armado con un contenido de finos (275 kg/m3) superior al límite permitido por la Instrucción EHE-08 (175 kg/m3). En el rango estudiado, el contenido de finos apenas afectó a la respuesta a flexión. La resistencia a cortante de vigas con alto contenido de finos fue menor que la de las vigas de hormigón convencional, en especial para las vigas con cuantía alta de armadura longitudinal y con armadura de cortante, con una reducción de hasta el 23 % en la carga última. Esta reducción se considera debida a la disminución de propiedades mecánicas del hormigón que afecta especialmente al cortante resistido por fricción en la fisura. Por último, los ensayos realizados han permitido verificar un modelo numérico de análisis no lineal evolutivo para predecir el comportamiento de estructuras de hormigón con distintos contenidos de finos.
This paper presents an experimental study on the flexural and shear behavior of reinforced concrete beams with a fines
content (275 kg/m3) higher than the limit value allowed by the Spanish Concrete Code EHE-08 (175 kg/m3). In the studied
range, the fines content scarcely affected the flexural response. The shear strength of the beams with a high content of fines was lower than that of the beams cast with conventional concrete, especially for those with a high longitudinal internal reinforcement ratio and with transversal stirrups, where the reduction of the ultimate load was up to 23 %. Such a reduction is considered due to the reduction of mechanical properties of concrete and that of the aggregate interlock along the crack length. Finally, the experimental results have allowed verifying a numerical model for the non-linear analysis of RC members to accurately predict the influence of the amount of fine aggregate on the structural response.Thermal performance of ventilated double skin façades with Venetian blindsParra Porcar, JordiGuardo Zabaleta, Alfredo de JesúsEgusquiza Estévez, EduardAlavedra Ribot, Perehttp://hdl.handle.net/2117/769522022-10-09T10:15:35Z2015-09-18T13:03:02ZThermal performance of ventilated double skin façades with Venetian blinds
Parra Porcar, Jordi; Guardo Zabaleta, Alfredo de Jesús; Egusquiza Estévez, Eduard; Alavedra Ribot, Pere
2015-09-18T13:03:02ZParra Porcar, JordiGuardo Zabaleta, Alfredo de JesúsEgusquiza Estévez, EduardAlavedra Ribot, PereAnalytical micro-modeling of masonry periodic unit cells : elastic propertiesDrougkas, AnastasiosRoca Fabregat, PedroMolins i Borrell, Climenthttp://hdl.handle.net/2117/769042022-10-09T05:42:06Z2015-09-17T12:42:46ZAnalytical micro-modeling of masonry periodic unit cells : elastic properties
Drougkas, Anastasios; Roca Fabregat, Pedro; Molins i Borrell, Climent
A model for the analysis of masonry periodic unit cells based on detailed micro-modeling principles is presented: an analytical model capable of calculating the orthotropic elastic properties of masonry composites. Several masonry typologies are investigated in the present paper, some of which have received very limited attention, such as Flemish bond walls.; The purpose of the model is to achieve the level of detail made possible by the use of detailed micro-modeling techniques while keeping computational costs at a minimum in order to be used as a basis for two-scale modeling of masonry.; The results obtained from the described model are compared with experimental data from the existing relevant literature as well as with numerical results obtained from the finite element analysis of masonry periodic unit cells. A parametric investigation is also performed, in which the accuracy of the model is compared against a FE benchmark.
2015-09-17T12:42:46ZDrougkas, AnastasiosRoca Fabregat, PedroMolins i Borrell, ClimentA model for the analysis of masonry periodic unit cells based on detailed micro-modeling principles is presented: an analytical model capable of calculating the orthotropic elastic properties of masonry composites. Several masonry typologies are investigated in the present paper, some of which have received very limited attention, such as Flemish bond walls.; The purpose of the model is to achieve the level of detail made possible by the use of detailed micro-modeling techniques while keeping computational costs at a minimum in order to be used as a basis for two-scale modeling of masonry.; The results obtained from the described model are compared with experimental data from the existing relevant literature as well as with numerical results obtained from the finite element analysis of masonry periodic unit cells. A parametric investigation is also performed, in which the accuracy of the model is compared against a FE benchmark.Effective width equations accounting for element interaction for cold-formed stainless steel square and rectangular hollow sectionsBock Montero, MarinaReal Saladrigas, Estherhttp://hdl.handle.net/2117/766592020-07-23T21:31:19Z2015-09-07T13:14:13ZEffective width equations accounting for element interaction for cold-formed stainless steel square and rectangular hollow sections
Bock Montero, Marina; Real Saladrigas, Esther
Square and rectangular hollow sections (SHS and RHS, respectively) featuring high height-to-width (aspect) ratios have shown to offer improved ultimate capacity due to the effects of the interaction between the elements within the cross-section which are particularly significant for slender cross-sections (class 4) undergoing local buckling. The European design rule dealing with stainless steel, EN 1993-1-4 (2006), utilises the concept of cross-section classification and the effective width method for the design of slender cross-sections susceptible to local buckling neglecting such interaction effects, hence yielding over conservative predictions. This paper examines the benefits of element interaction effects on cold-formed ferritic stainless steel compressed sections on the basis of carefully validated finite element models. Following parametric studies, the applicability of various alternative design approaches accounting for element interaction to ferritic stainless steel is assessed and effective width curves, as well as a Class 3 limiting slenderness equation, are derived herein as an explicit function of the aspect ratio. Comparisons with the loads achieved in the FE models have shown that the proposed effective width equations allowing for the benefits of element interaction improve capacity predictions making design more cost-effective.
2015-09-07T13:14:13ZBock Montero, MarinaReal Saladrigas, EstherSquare and rectangular hollow sections (SHS and RHS, respectively) featuring high height-to-width (aspect) ratios have shown to offer improved ultimate capacity due to the effects of the interaction between the elements within the cross-section which are particularly significant for slender cross-sections (class 4) undergoing local buckling. The European design rule dealing with stainless steel, EN 1993-1-4 (2006), utilises the concept of cross-section classification and the effective width method for the design of slender cross-sections susceptible to local buckling neglecting such interaction effects, hence yielding over conservative predictions. This paper examines the benefits of element interaction effects on cold-formed ferritic stainless steel compressed sections on the basis of carefully validated finite element models. Following parametric studies, the applicability of various alternative design approaches accounting for element interaction to ferritic stainless steel is assessed and effective width curves, as well as a Class 3 limiting slenderness equation, are derived herein as an explicit function of the aspect ratio. Comparisons with the loads achieved in the FE models have shown that the proposed effective width equations allowing for the benefits of element interaction improve capacity predictions making design more cost-effective.Selection of measurement sets in static structural identification of bridges using observability treesLozano Galant, José AntonioNogal Macho, MaríaTurmo Coderque, JoséCastillo Ron, Enriquehttp://hdl.handle.net/2117/766042020-07-23T21:19:09Z2015-09-03T13:15:36ZSelection of measurement sets in static structural identification of bridges using observability trees
Lozano Galant, José Antonio; Nogal Macho, María; Turmo Coderque, José; Castillo Ron, Enrique
This paper proposes an innovative method for selection of measurement sets in static parameter identification of concrete or steel bridges. This method is proved as a systematic tool to address the first steps of Structural System Identification procedures by observability techniques: the selection of adequate measurement sets. The observability trees show graphically how the unknown estimates are successively calculated throughout the recursive process of the observability analysis. The observability trees can be proved as an intuitive and powerful tool for measurement selection in beam bridges that can also be applied in complex structures, such as cable-stayed bridges. Nevertheless, in these structures, the strong link among structural parameters advises to assume a set of simplifications to increase the tree intuitiveness. In addition, a set of guidelines are provided to facilitate the representation of the observability trees in this kind of structures. These guidelines are applied in bridges of growing complexity to explain how the characteristics of the geometry of the structure (e.g. deck inclination, type of pylon-deck connection, or the existence of stay cables) affect the observability trees. The importance of the observability trees is justified by a statistical analysis of measurement sets randomly selected. This study shows that, in the analyzed structure, the probability of selecting an adequate measurement set with a minimum number of measurements at random is practically negligible. Furthermore, even bigger measurement sets might not provide adequate SSI of the unknown parameters. Finally, to show the potential of the observability trees, a large-scale concrete cable-stayed bridge is also analyzed. The comparison with the number of measurements required in the literature shows again the advantages of using the proposed method.
2015-09-03T13:15:36ZLozano Galant, José AntonioNogal Macho, MaríaTurmo Coderque, JoséCastillo Ron, EnriqueThis paper proposes an innovative method for selection of measurement sets in static parameter identification of concrete or steel bridges. This method is proved as a systematic tool to address the first steps of Structural System Identification procedures by observability techniques: the selection of adequate measurement sets. The observability trees show graphically how the unknown estimates are successively calculated throughout the recursive process of the observability analysis. The observability trees can be proved as an intuitive and powerful tool for measurement selection in beam bridges that can also be applied in complex structures, such as cable-stayed bridges. Nevertheless, in these structures, the strong link among structural parameters advises to assume a set of simplifications to increase the tree intuitiveness. In addition, a set of guidelines are provided to facilitate the representation of the observability trees in this kind of structures. These guidelines are applied in bridges of growing complexity to explain how the characteristics of the geometry of the structure (e.g. deck inclination, type of pylon-deck connection, or the existence of stay cables) affect the observability trees. The importance of the observability trees is justified by a statistical analysis of measurement sets randomly selected. This study shows that, in the analyzed structure, the probability of selecting an adequate measurement set with a minimum number of measurements at random is practically negligible. Furthermore, even bigger measurement sets might not provide adequate SSI of the unknown parameters. Finally, to show the potential of the observability trees, a large-scale concrete cable-stayed bridge is also analyzed. The comparison with the number of measurements required in the literature shows again the advantages of using the proposed method.