Exploração da análise custo-benefício na redução do risco sísmico

Masonry buildings comprise more than 50% of the masonry building stock in Portugal according to the 2011 national census. This construction typology has revealed a poor performance during the destructive events which took place in Portugal in the last century. Past efforts to characterize the seismic vulnerability of this type of construction have focused mostly on individual buildings. In this dissertation, cost-benefit analyses are performed for a set of retrofitting techniques compatible with masonry buildings. Chapter 1 presents the aims, motivations and scope of the research, hence explaining the context of the current research. In Chapter 2, a literature review is presented with the purpose to introduce the reader to topics associated to this research. Important topics are addressed as building stock characterisation, physical damage and fatality assessment, retrofitting and cost-benefit analysis. Chapter 3 is devoted to the geometric and mechanical characterization of the two most common stone masonry building typologies in Portugal, limestone and granite. A statistical treatment is made, and probability density functions are defined for important structural features. Chapter 4 aims at implementing advanced numerical models and developing damage fragility functions for masonry buildings. Chapter 5 discusses the state-of-the-practice in fatality assessment and introduces the outcomes of the advanced structural analysis to propose a new fatality assessment framework. In Chapter 6, retrofitting techniques compatible with masonry buildings in Portugal are modelled and numerically assessed, to develop fragility and fatality vulnerability functions. Chapter 7 comprises the implementation of consequence functions at the national scale. Finally, the main outcomes, principal conclusions and future research is discussed in Chapter 8.Os edifícios de alvenaria representam mais de 50% do parque habitacional de alvenaria em Portugal de acordo com o recenseamento nacional de 2011. Este tipo de construção revelou ter um fraco desempenho durante os eventos destrutivos ocorridos em Portugal no século passado. Os esforços anteriores para caracterizar a vulnerabilidade sísmica deste tipo de construção concentraram-se principalmente em edifícios individuais. Nesta tese é realizada uma análise custo-benefício para um conjunto de técnicas de reforço compatíveis com edifícios de alvenaria. O Capítulo 1 apresenta, de forma sucinta, os objetivos, motivações, e a estrutura da tese. No Capítulo 2, é apresentada uma revisão da literatura com o objetivo de apresentar aos leitores tópicos relacionados com esta investigação desenvolvida. O Capítulo 3 é dedicado à caracterização geométrica e mecânica de dois tipos de edifícios de alvenaria de pedra mais comuns em Portugal, calcário e granito. É frito um tratamento estatístico a partir do qual são definidas funções de densidade de probabilidade para caracterizar os parâmetros estruturais mais importantes. O Capítulo 4 visa a implementação de modelos numéricos avançados e o desenvolvimento de funções de fragilidade para edifícios de alvenaria. No Capítulo 5 discute-se o estado da prática na avaliação de fatalidades e apresentam-se os resultados da análise estrutural avançada no procedimento de avaliação de fatalidades. No Capítulo 6, são avaliadas com recurso a modelos numéricos um conjunto de técnicas de reforço compatíveis com edifícios de alvenaria em Portugal e são ainda desenvolvidas funções de vulnerabilidade e fragilidade para fatalidades, tendo em conta o impacto dessas técnicas no comportamento sísmico destes edifícios. O Capítulo 7 cobre a implementação das funções de consequência à escala nacional. Finalmente, o Capítulo 8 compila as principais conclusões e apresenta sugestões de futura investigação a desenvolver neste campo.Programa Doutoral em Engenharia Civi

Seismic vulnerability assessment of Portuguese adobe buildings

Adobe construction represents 5.3% of the total Portuguese building stock according to the latest National Housing Census. The distribution of these adobe buildings is scattered across the country, with higher density in the central region and in Algarve in the south, where the seismic hazard is highest. A large proportion of these buildings are still in use for residential and commercial purposes and are of historical significance, contributing to the cultural heritage of the country. Adobe buildings are known to exhibit low seismic resistance due to their brittle behavior, thus making them vulnerable to ground shaking and more prone to structural damage that can potentially cause human fatalities. Three buildings with one-story, two-stories, and two-stories plus an attic were numerically modeled using solid and contact elements. Calibration and validation of material properties were carried out following experimental results. A set of 30 ground motion records with bi-directional components were selected, and non-linear time-history analyses were performed until complete collapse occurred. Two novel engineering demand parameters (EDPs) were used, and damage thresholds were proposed. Finally, fragility and fatality vulnerability functions were derived. These functions can be used directly in seismic risk assessment studies.This work was funded by the Foundation for Science and Technology (FCT)—Aveiro Research Centre for Risks and Sustainability in Construction (RISCO), Universidade de Aveiro, Portugal in the framework of research project PTDC/ECI-EST/31865/2017 MitRisk—Framework for seismic risk reduction resorting to cost-effective retrofitting solutions

Seismic vulnerability assessment of Portuguese masonry buildings

According to the 2011 National Housing Census, masonry buildings comprise more than 50% of the Portuguese building stock. This type of construction has demonstrated a poor performance during the destructive events that struck Portugal in the last century (e.g., 1909 M6.3 Benavente, 1969 M7.8 Algarve, 1980 M6.9 Azores). While some efforts have been made towards the vulnerability assessment of individual masonry buildings or the residential building stock at the national scale, this building class has been the target of limited research. In this study, a comprehensive database of material and geometric properties of granite and limestone buildings was used to generate complex 3D numerical models. These models were subjected to nonlinear time history analysis to derive fragility curves considering the record-to-record and building-to-building variability. The structural damage was defined using two novel engineering demand parameters, and the resulting fragility functions were compared against other existing models. These results can be used directly to generate earthquake scenarios at the country scale or in probabilistic seismic risk analysis to identify regions where risk reduction measures should be prioritized

Polyclonal antibodies for the detection of Trypanosoma cruzi circulating antigens

Detection of Trypanosoma cruzi antigens in clinical samples is considered an important diagnostic tool for Chagas disease. The production and use of polyclonal antibodies may contribute to an increase in the sensitivity of immunodiagnosis of Chagas disease.Polyclonal antibodies were raised in alpacas, rabbits, and hens immunized with trypomastigote excreted-secreted antigen, membrane proteins, trypomastigote lysate antigen and recombinant 1F8 to produce polyclonal antibodies. Western blot analysis was performed to determine specificity of the developed antibodies. An antigen capture ELISA of circulating antigens in serum, plasma and urine samples was developed using IgY polyclonal antibodies against T. cruzi membrane antigens (capture antibody) and IgG from alpaca raised against TESA. A total of 33 serum, 23 plasma and 9 urine samples were analyzed using the developed test. Among serum samples, compared to serology, the antigen capture ELISA tested positive in 55% of samples. All plasma samples from serology positive subjects were positive in the antigen capture ELISA. All urine positive samples had corresponding plasma samples that were also positive when tested by the antigen capture ELISA.Polyclonal antibodies are useful for detection of circulating antigens in both the plasma and urine of infected individuals. Detection of antigens is direct evidence of the presence of the parasite, and could be a better surrogate of current infection status

Estimación de la vulnerabilidad sísmica de viviendas de albañilería confinada de Lima

El objetivo de este trabajo es desarrollar funciones de fragilidad y de vulnerabilidad para edificios informales de albañilería confinada de Lima, Perú. Estas funciones pueden ser utilizadas para desarrollar escenarios sísmicos a escala urbana. Se ha desarrollado una base de datos a partir de encuestas realizadas en estudios previos. Esta base de datos contiene información acerca de las características estructurales de viviendas informales de albañilería confinada de la ciudad de Lima (e. g. densidad de muros, área de la edificación, altura). Cada característica ha sido modelada mediante funciones distribución de probabilidad. Utilizando simulación Montecarlo se ha generado una población sintética de viviendas de albañilería confinada a partir de las funciones de probabilidad que describen la muestra. Posteriormente se ha utilizado un método simplificado para calcular la curva de capacidad de la población sintética mencionada. En este punto, la demanda sísmica fue definida utilizando un grupo de registros sísmicos. Estos registros fueron seleccionados de acuerdo a la actividad sísmica de la costa del Perú (e. g. tipo de ruptura, distribución de intensidad sísmica, niveles de magnitud sísmica). Se utilizó el método DBELA (Displacement-based Earthquake Loss Assessment) para determinar el estado de daño de cada vivienda cuando es sujeta a cada registro sísmico. Se ensamblaron matrices de probabilidad de daño a partir de los resultados obtenidos. Posteriormente se obtuvo el periodo de aceleración espectral más eficiente para representar los estados de daño registrados. Los datos obtenidos se ajustaron a funciones de fragilidad utilizando el método de mínimos cuadrados. Finalmente, se definieron factores de daño de acuerdo a las recomendaciones de HAZUS (Hazard in the United States). Se obtuvieron curvas de vulnerabilidad de la convolución entre las curvas de fragilidad y los factores de daño. Se han utilizado las funciones obtenidas para estimar daños en sismos con nivel de ocurrencia “rara”. Aunque en nuestro país no se tienen datos precisos sobre los efectos que estos sismos tendrían en viviendas de albañilería confinada, los resultados muestran valores razonables en relación a los que se han registrado en anteriores sismos. De la interpretación de las curvas se esperan aproximadamente 10% y 40% de colapsos en viviendas informales de 1 piso y de 2 pisos respectivamente.Tesi

Analytical vulnerability functions for assessing fatalities in masonry buildings

The assessment of human losses and injuries due to earthquakes is critical for the development of risk reduction measures. Yet, most vulnerability studies have focused on the derivation of fragility functions for structural damage, neglecting the evaluation of the human impact. In this study, we implemented a fatality vulnerability assessment procedure based on advanced structural modelling, with an application to typical limestone and granite masonry buildings in Portugal. We performed nonlinear time‐history analysis on 3D numerical models whose characteristics were sampled from statistical models representing the geometric and mechanical properties of this type of construction. Engineering demand parameters, such as volume of loss and volume of survivable space, were estimated and converted into a fatality rate based on observations from past fatal earthquakes. We compared these vulnerability functions with other proposals from the literature in which conventional fragility functions are directly combined with collapse and fatality rates. Finally, the resulting vulnerability functions were tested for two earthquake scenarios for Portugal. The results from this study indicate that the conventional approach for fatality modelling tends to underestimate human losses for strong ground shaking due to the inability to account for catastrophic structural collapses. The fatality vulnerability functions developed in this work can be directly used in probabilistic seismic risk analysis or the assessment of earthquake scenarios

Antigen capture ELISA in urine samples.

<p>Antigen capture ELISA in urine samples.</p

Results of the antigen capture ELISA compared to serology and qPCR.

<p>Results of the antigen capture ELISA compared to serology and qPCR.</p

Animal immunization scheme.

<p>Animal immunization scheme.</p

Western blot analysis of polyclonal antibodies.

<p>Western blot was performed using 147.7 μg of membrane antigen, 400 μg of trypomastigote excretory secretory antigen (TESA) or 447.7 μg of trypomastigote lysate antigen (TLA). The blot was developed using as primary antibody; A: purified IgG3 from alpaca immunized with <i>T</i>. <i>cruzi</i> antigens; B: purified IgG from rabbit; and C: purified IgY from eggs. Lane 1 = Pre-Immune IgG/IgY, lane 2 = post-immune purified IgG/IgY, lane 3 = human sera (IgG) from a Chagas positive subject; lane 4 = human sera (IgG) from a Chagas negative subject; lane 5 = human sera (IgM) from a subject with acute Chagas disease; lane 6 = IgM from a human subject negative to Chagas disease. Arrows indicate unique proteins recognized by the developed polyclonal antibodies.</p