Dynamic identification and static loading tests of timbrel vaults: application to a Modernist 20th century heritage structure

This is an Accepted Manuscript of an article published by Taylor & Francis Group in International Journal of Architectural Heritage on 2017, available online at: http://www.tandfonline.com/10.1080/15583058.2016.1277566This paper presents the study of the structural performance of a set of timbrel vaults belonging to the so-called Administration Pavilion of the Hospital de Sant Pau, a large-scale hospital complex located in Barcelona. The paper includes three parts. First, the Administration pavilion of Hospital de Sant Pau is described by putting the emphasis on the geometry of the masonry vaults and the combined utilisation of steel and masonry structural members. Second, laboratory and in-situ experiments are discussed. Finally, the behaviour observed during the dynamic-identification and the static-loading tests is simulated by means of FEM analysis. The FEM models prepared to analyse the vaults take explicitly into account the direct effect of secondary masonry structural elements, such as the upper slab and the extrados stiffening diaphragms. The comparison indicates that the consideration of these structural elements is essential for an adequate FEM simulation of both the dynamic and the static behaviour of the timbrel vaults.Peer ReviewedPostprint (author's final draft

Comparison of similitude laws applied to multi-storey masonry structures with flexible diaphragms

This is an Accepted Manuscript of an article published by Taylor & Francis Group in Journal of Earthquake Engineering on 2022, available online at: http://www.tandfonline.com/10.1080/13632469.2022.2040655.The present paper discusses similitude laws employed for the shaking-table tests of masonry structures with flexible diaphragms. Two tasks are tackled. First, the paper presents a literature review on similitude laws. The discussion focuses on Cauchy and Cauchy-Froude laws. Second, numerical analysis is performed to examine the accuracy and adequacy of the aforementioned two laws. Two previously performed shaking-table tests are taken advantage of as the case studies. The paper explores the ideal applications of similitude laws to the shaking table tests of masonry structures with flexible diaphragms by comparing the behaviour between full-scale prototypes and reduced-scale models.Peer ReviewedPostprint (author's final draft

Modelling and structural analysis of historical masonry systems including vaulted structure

The conservation of historic structures has been given special attention due to their cultural, social and economic importance. However they often show considerable structural vulnerability and have been seriously damaged by natural disasters including earthquakes. An excessive loss of architectural heritage has occurred because of earthquakes. A safety assessment and restoration practice on historical structures has been tackled extensively by professionals including architects and engineers. However, structural assessment of historical buildings is a complex task. Complexity comes from insufficient understanding of the characteristic of historical materials, limited knowledge of the seismic response of historical structures and yet-unknown structural deterioration due to the past natural disasters. Today it is perceived that nonlinear FEM analysis permits detailed study of historical masonry structures. However, in some cases, its application poses difficulties. The difficulties derive from the definition of material properties, the definition of a complex geometry and the analysis procedures. The results depend on the material properties considerably. However, it is not easy to describe appropriately the behaviour of historical materials including masonry in the FEM analysis. The definition of a complex geometry is challenging although the discretisation of accurate geometry is crucial. As for the analysis procedure, one of the difficulties is observed in seismic assessment. FEM-based nonlinear dynamic analysis permits close observation of seismic response of a historical masonry structure but it requires excessive computational effort, for a large-scale structure in particular. On the other hand, pushover can be adopted more efficiently than nonlinear dynamic analysis but the obtained result can be less reliable. All these considerations indicate that the understanding of FEM approaches still needs to be deepened to adopt more accurately and at the same time efficiently for the analysis of historical structures. The present research discusses the applicability of existing nonlinear FEM approaches to the study of masonry historical structures. The FEM analysis is adopted to the analysis of real and complex structures including mixed steel and masonry vaulted systems belonging to the Hospital de Sant Pau in Barcelona and a large single-nave church damaged by the 2009 Abruzzo earthquake. As a final outcome of the research, the conclusions provided criteria and guidelines for the analysis of these types of structures under vertical loading and seismic forces. The achievement of the research will contribute to both engineers and researchers who are involved in the conservation of historical masonry structures especially by means of FEM analysis.La conservación de las estructuras históricas llama la atención debido a su importancia cultural, social y económica. Sin embargo, muestran considerablemente vulnerabilidad estructural y se han dañado seriamente por desastres naturales como terremotos. La excesiva pérdida de patrimonio arquitectónico ha ocurrido a causa de los terremotos. Se ha llevado a cabo la evaluación de la seguridad y la práctica de restauración de estructuras históricas ampliamente por los profesionales incluso arquitectos e ingenieros. No obstante, la evaluación estructural de los edificios históricos es una tarea compleja. La complejidad viene de la comprensión insuficiente de las características de los materiales históricos, conocimiento limitado de la respuesta sísmica de estructuras históricas y deterioro estructural todavía desconocido debido a los desastres naturales pasados. Hoy en día se percibe que el análisis de elementos finitos (FEA) no lineal permite el estudio detallado de las estructuras de mampostería históricos. Con todo, en algunos casos, no es sencilla la aplicación de ello. Las dificultades vienen de la definición de las propiedades del material, la definición de una geometría compleja y los procedimientos de análisis. Los resultados dependen de las propiedades del material considerablemente. Sin embargo, no es fácil describir adecuadamente en el FEA el comportamiento de materiales históricos como mampostería. Es difícil definir la geometría compleja es crucial aunque la discretización de la geometría exacta. En cuanto al procedimiento de análisis, se observa una de las dificultades en la evaluación sísmica. Análisis dinámico no lineal del FEA permite la observación precisa de la respuesta sísmica de las estructuras de mampostería histórica pero requiere el esfuerzo computacional excesivo, especialmente por una estructura a gran escala. Por otro lado, pushover puede ser más eficiente que el análisis dinámico no lineal pero el resultado obtenido por ello puede ser menos fiable. Estas consideraciones indican que la compresión del FEA necesita profundizarse para que se adopte FEA más precisamente y más eficientemente para el análisis de estructuras históricas. La presente investigación analiza la aplicabilidad del FEA no lineal acerca del estudio de las estructuras históricas de mampostería. El FEA se adopta para el análisis de las estructuras reales y complejas incluso los sistemas abovedados de la combinación del acero y mampostería pertenecientes al Hospital de Sant Pau de Barcelona y una gran iglesia de una sola nave dañada por el terremoto de Abruzzo 2009. Como resultado final de la investigación, las conclusiones presentan criterios y directrices para el análisis de estés tipos de estructuras bajo cargas verticales y sísmicas. El fruto de la investigación contribuirá a ambos ingenieros e investigadores que participan en la conservación de las estructuras de mampostería históricos sobre todo por medio del FEA

Assessment and rehabilitation of historic concrete structures Case study1-Citta’ della musica in Marghera-

This dissertation deals with the application of the methodology of preservation on historic concrete constructions. The early concrete structure will be analysed from several points of view: artistic or architectonic value, construction history, structural behaviour, procedures historically followed for the design, on-site and laboratory testing of constitutive materials, modelling and seismic analyses. The past industrial building in Marghera is taken as a case study here. It was built in the 50s and is going through the conversion into the commercial and business complex

Zero-shot domain adaptation of anomalous samples for semi-supervised anomaly detection

Semi-supervised anomaly detection~(SSAD) is a task where normal data and a limited number of anomalous data are available for training. In practical situations, SSAD methods suffer adapting to domain shifts, since anomalous data are unlikely to be available for the target domain in the training phase. To solve this problem, we propose a domain adaptation method for SSAD where no anomalous data are available for the target domain. First, we introduce a domain-adversarial network to a variational auto-encoder-based SSAD model to obtain domain-invariant latent variables. Since the decoder cannot reconstruct the original data solely from domain-invariant latent variables, we conditioned the decoder on the domain label. To compensate for the missing anomalous data of the target domain, we introduce an importance sampling-based weighted loss function that approximates the ideal loss function. Experimental results indicate that the proposed method helps adapt SSAD models to the target domain when no anomalous data are available for the target domain

Partimento pedagogy and its modern application

The purpose of this doctoral dissertation is to examine and advocate for the use of a historical keyboard improvisation pedagogy in both modern educational settings and individual learning environments as a self-contained, all-encompassing approach that is capable of producing a total musician who can successfully improvise, compose, and perform. My intent is not to discuss or advocate for reviving idiomatic historical improvisation; rather, I wish to examine how the theory of improvisation and interpretive performance support each other, and how learning improvisation can help fill gaps in the current classical training. Recently, there has been a growing awareness of the value of improvisation pedagogy which could compensate for the problems encountered in modern musical education; however, a concrete approach has yet to be established. My focus is on the pedagogical system called “partimento” and its modern application and adaptation. The partimento type of pedagogy was the standard procedure for learning music in the eighteenth century, but has only recently come to light as such. A more thorough investigation of partimento pedagogy reveals that musicians in the past, especially in the eighteenth century, learned music through a time-consuming but linear, logical, and efficient method, and everyone was destined to become the improviser-composer-performer as a reward for a fixed number of years of rigorous training. Currently, research on partimento is underway in a few North American universities and European conservatories that possess advanced music students; however, to date only a few texts targeting ordinary keyboard learners are available. In this project, I intend to create a sample curriculum for an undergraduate keyboard-skills class based on the integration of partimento pedagogy, and create a modern guide to partimento and classical improvisation for independent amateur learners. Then, I will use select organ compositions by Johann Sebastian Bach as case studies through which to demonstrate the effectiveness of musical analysis based on partimento pedagogy from a performer’s perspective

Review of different pushover analysis methods applied to masonry buildings and comparison with nonlinear dynamic analysis

This is an Accepted Manuscript of an article published by Taylor & Francis Group in Journal of Earthquake Engineering on 2016, available online at: http://www.tandfonline.com/doi/full/10.1080/13632469.2016.1210055.This article presents the comparison among different nonlinear seismic analysis methods applied to masonry buildings, i.e., pushover analyses with invariant lateral force distributions, adaptive pushover analysis and nonlinear dynamic analysis. The study focuses on the influence of lateral force distribution on the results of the pushover analysis. Two simple benchmark case studies are considered for the purpose of the research, i.e., a four-wall masonry building prototype without floor rigid diaphragms and a two-wall system with a cross-vault. The comparative study offers a useful review of pushover analysis methods for masonry structures and shows advantages and possible limitations of each approach.Peer ReviewedPostprint (author's final draft

Influence of adding carbon nanotubes on photoelectric conversion properties of dye-doped titania gel

Multiwalled carbon nanotubes (MWCNTs) were incorporated into amorphous dye-doped titania gel by the sol-gel method at room temperature. The working electrodes were prepared by coating the ITO glass with the sol-gel titania precursor containing the dye and MWCNTs. The photoelectric conversion properties of the electrodes were examined by simple spectroscopic and electric measurements. The photocurrent spectrum originated from the absorption of the dye. The short circuit photocurrent was enhanced by adding a small amount of MWCNTs evenly to the amorphous dye-doped titania gel. The open circuit voltage was due to the semiconducting characteristics property of the titania gel. The experimental results indicated the electron transport from the dye excited states to the MWCNTs through the titania gel. The MWCNTs functioned as bridges between the titania and ITO. Steam treatment of the titania gel electrodes significantly increased the photoelectric performance due to crystallization of the titania and enhancement of the dye-titania interaction forming the chelate complex on the titania particle surface.ArticleRESEARCH ON CHEMICAL INTERMEDIATES. 38(8):1857-1869 (2012)journal articl