10 research outputs found
Evaluation of different retrofit strategies for RC school buildings using integrated multi-criteria procedures
No full textSeismic assessment of school building in Italy: retrofit and risk classification
No full textThe potentially high vulnerability and poor performance of existing school buildings in Italy, reported after past seismic events, has raised awareness of the need to improve their seismic performance. In this context, a research project dealing with assessing the seismic risk of school buildings was conducted on representative typologies of the school building population in Italy. This paper explores some retrofit strategies for three specific school buildings representing the most common typologies of the Italian school building stock. A performance assessment was carried out using detailed numerical models developed to recreate the main structural deficiencies documented in similar buildings. Based on the performance assessment, retrofit schemes were proposed to address the main structural deficiencies and to meet code requirements for the different limit states. These requirements are set to limit the damage to non-structural elements and prevent non-ductile failure mechanisms in the structural systems, following a typical code and practitioner-oriented process. The retrofit alternatives were then evaluated through increasing shaking intensities to quantify risk-based decision variables such as expected annual loss and collapse safety. The results indicate the efficiency of the retrofit options utilized in reducing both the economic losses and collapse vulnerability of the buildings. Finally, the seismic risk classification guidelines, implemented recently in Italy, were applied at a national scale to estimate the seismic risk on existing school buildings in the Italian peninsula and the risk reduction achieved by each retrofit alternative. Consequently, budget programs can be derived based on national risk maps, prioritizing the investment of seismic retrofit interventions in regions of vulnerable school buildi
Seismic retrofit of existing school buildings in Italy: Performance evaluation and loss estimation
No full textThe seismic vulnerability and inadequate behaviour of existing school buildings observed during past earthquakes in Italy have raised awareness of the need to upgrade their performance. This paper examines different retrofit strategies for three case study school buildings, representing the main typologies found within the Italian school building stock. The three building typologies investigated in this study are representative of reinforced concrete (RC), precast concrete (PC) and unreinforced masonry (URM) school buildings. A seismic performance assessment was carried out using detailed numerical models that consider the main structural deficiencies documented for older buildings in Italy, generally designed and built before the 1970s. The retrofit interventions were specifically aimed at mitigating these main structural deficiencies in order to meet current building code limit state requirements. These requirements are set to limit the damage to non-structural elements and prevent non-ductile failure mechanisms in the structural system, following a typical building code and practitioner-oriented process. The retrofit alternatives were then evaluated through increasing ground shaking intensities to quantify risk-based decision variables, such as the expected annual loss and mean annual frequency of collapse. The results highlight the level of adequacy of each retrofit option in reducing both the economic losses and collapse vulnerability. To predict the economic feasibility of these interventions, a cost-benefit analysis was also conducted using estimated implementation costs of each retrofit alternative. Lastly, the results were also compared with the outcome of the seismic risk classification guidelines, recently proposed in Italy
COMPARATIVE STUDY OF THE SEISMIC DEMAND ESTIMATION ON ACCELERATION-SENSITIVE NONSTRUCTURAL ELEMENTS
No full textThe latest middle and high intensity seismic events have demonstrated that the potential seismic
risk of nonstructural elements compromises a building’s overall seismic performance, affecting
especially the building operability. Additionally, nonstructural elements account for a considerably
large fraction of the total earthquake economic losses and total building costs. Several
international building codes provide methods to approximate the seismic acceleration demand
on nonstructural elements; however, the provided guidelines may not accurately estimate the
actual seismic demand leading to unconservative designs of acceleration-sensitive nonstructural
elements. This study compares the acceleration demand on nonstructural elements calculated
by using international building codes and state-of-the-art estimation methodologies with actual
floor acceleration response spectra from nonlinear time history analysis. Two moment-resisting
steel frames of three and nine stories were selected as case-study buildings. The FEMA P-695
far-field ground motion set was scaled to an equivalent design intensity and it was used as the
input seismic load. The floor absolute accelerations were recorded on the first and last stories
of both buildings and the median floor absolute acceleration response spectra were calculated.
The spectral floor accelerations were determined considering a wide range of nonstructural
periods and the results were compared with the estimated floor spectral acceleration obtained
from the building code provisions and the novel methodologies. The results point out that
current building codes tend to mislead the design of nonstructural elements by underestimating
the actual acceleration demand on these components. On the other hand, the state-of-the-art
methodologies provide a better estimation of the acceleration demand on nonstructural elements
without the need for conducting nonlinear time history analyses
Seismic Resilience Assessment in Optimally Integrated Retrofitting of Existing School Buildings in Italy
No full textModern society requires that structures exhibit greater levels of resilience, especially under earthquakes. The seismic resilience of buildings is thus gaining increased attention as a particular, beyond-code approach. Seismically retrofitted buildings behave satisfactorily under expected earthquake scenarios; however, this does not guarantee operativity after a seismic event. This study critically reviews several methods currently available in the literature that quantify the seismic resilience level of buildings from different perspectives. An existing reinforced concrete school building, retrofitted according to four distinct strategies, is first evaluated in terms of seismic resilience levels. The overview and critical analysis of available resilience assessment frameworks determine the most suitable parameters to measure the seismic resilience for buildings. Subsequently, this metric is incorporated as an additional decision variable into an integrated seismic and energy retrofitting set of strategies. A multicriteria decision-making analysis is performed to select the optimally combined seismic and energy retrofitting alternative under social, technical, environmental evaluation, and seismic resilience aspects. We show how resilience impacts the preference for integrated seismic and energy retrofitting strategies, especially when this metric is considered as an annualized expected value
Control de calidad y caracterización de materiales de hormigón compactado con rodillo (hcr) utilizado en el proceso constructivo en la presa manduriacu (Guayllabamba – Pichincha –Ecuador)
No full textEste trabajo consiste en el control de calidad y caracterización de agregados provenientes de las cercanías del proyecto hidroeléctrico mandariacu, para ello se realizaron ensayos normalizados a fin de conocer la idoneidad de estos materiales y obtener su máximo provecho. Por lo cual, se diseñaron curvas granulométricas y pruebas de densidad con la finalidad de establecer diseños de hormigón compactado con rodillo con distintos tipos y cantidades de cemento puzolánicos para posteriormente evaluar el desempeño de estas mezclas tanto en estado fresco como endurecido mediante la ejecución de ensayos destructivos. Este trabajo es tan solo un apoyo o preliminar, mas no un proyecto definitivo.GuayaquilIngeniero CivilXX
Análisis de sensibilidad de parámetros normativos locales e internacionales en el desempeño sísmico: Optimización de estrategias de reforzamiento en una edificación de cinco pisos ubicado en el Cantón Guayaquil, Provincia del Guayas – Ecuador.
No full textEste proyecto analiza la sensibilidad de parámetros normativos sísmicos utilizados en
desempeño estructural de una estructura con pórticos resistentes a momento de
hormigón armado ubicada en Guayaquil - Ecuador. Se comparan las normativas NEC15, E.30-18, ASCE-22 y la NTC-18 mediante un análisis de sensibilidad aplicada al
modelado estructural desarrollado en ETABS identificando los parámetros que más
influyen en la respuesta sísmica. Finalmente se proponen estrategias de reforzamiento
optimizadas para mejorar la seguridad estructural de la estructura estudiada.This project analyzes the sensitivity of seismic regulatory parameters used in the
structural performance of a reinforced concrete moment-resisting frame located in
Guayaquil, Ecuador. The NEC-15, E.30-18, ASCE-22, and NTC-18 standards are
compared through a sensitivity analysis applied to the structural model developed in
ETABS, identifying the parameters that most influence the seismic response. Finally,
optimized reinforcement strategies are proposed to improve the structural safety of the
studied structure.
Keywords: Sensitivity, Frame, Reinforcement, ETABS
Evaluación sísmica y diseño de reforzamiento estructural de una edificación de uso especial de 1133 m2 con pórticos resistente a momento de hormigón armado, ubicado en la ciudad de Guayaquil, aplicando la norma NEC-2015 a través del análisis PUSHOVER.
No full textLa seguridad sísmica de las edificaciones de uso especial es una prioridad en zonas de
alta peligrosidad sísmica, como la ciudad de Guayaquil, Ecuador. Esta investigación se
centra en la evaluación sísmica y el diseño de reforzamiento estructural de una
edificación de 1133 m² con sistema de pórticos resistentes a momento de hormigón
armado. El objetivo principal es mejorar su desempeño sísmico para garantizar la
seguridad de vida de sus habitantes y la prevención al colapso después de un evento
sísmico. La metodología aplicada se basa en un análisis estático no lineal (PUSHOVER),
conforme a los lineamientos de la Norma Ecuatoriana de la Construcción (NEC-2015).
Para ello, se utilizó software especializado para modelar la estructura y evaluar su
respuesta ante aplicaciones de cargas laterales monotónicas. La evaluación inicial
permitió identificar las debilidades estructurales críticas, como deficiencias en columnas,
que pueden comprometer la estabilidad global de la edificación. El diseño de
reforzamiento incluyó técnicas de encamisado de columnas con concreto adicional para
incrementar la rigidez de la estructura. Los resultados muestran que el desempeño
sísmico de la edificación mejoro, cumpliendo la demanda de desplazamiento por la
norma NEC-2015, garantizando la seguridad de sus ocupantes y la prevención al
colapso. La investigación demuestra la eficacia de la metodología de evaluación y diseño
de reforzamiento aplicada, la cual es replicable en otras edificaciones de uso especial
con sistemas estructurales similares. Este trabajo contribuye a la mejora de la resiliencia
estructural de edificios críticos en zonas de alta peligrosidad sísmica, reforzando la
seguridad de la comunidad.Seismic safety of special-use buildings is a priority in areas of high seismic risk, such as
the city of Guayaquil, Ecuador. This research focuses on the seismic evaluation and
structural reinforcement design of a 1133 m² building with a concrete moment-resistant
frame system. The main objective is to improve its seismic performance to ensure the life
safety of its inhabitants and prevent collapse after a seismic event. The applied
methodology is based on a non-linear static analysis (PUSHOVER), according to the
guidelines of the Ecuadorian Construction Standard (NEC-2015). For this purpose,
specialized software was used to model the structure and evaluate its response to
monotonic lateral load applications. The initial evaluation allowed identifying critical
structural weaknesses, such as deficiencies in columns, which may compromise the
overall stability of the building. The reinforcement design included column casing
techniques with additional concrete to increase the rigidity of the structure. The results
show that the seismic performance of the building improved, meeting the displacement
requirements of the NEC-2015 standard, ensuring the safety of its occupants and
preventing collapse. The research demonstrates the effectiveness of the applied retrofit
evaluation and design methodology, which can be replicated in other special-use
buildings with similar structural systems. This work contributes to improving the structural
resilience of critical buildings in high seismic hazard areas, reinforcing the safety of the
community
Democracy in the face of violence. A reflection on the social representations of political violence in Colombia through the reincorporation process of ex-guerrillas.
No full textilustraciones, diagramasEsta tesis examina las representaciones sociales de la violencia elaboradas por las y los
exguerrilleros de las FARC-EP, en relación con el proceso de reincorporación surgido
del Acuerdo de Paz en 2016 en Colombia. Explora las decisiones tomadas por estos
individuos y la posibilidad de abandonar el uso de las armas. De la misma manera la tesis
considera estas decisiones como un proceso mediado por las representaciones sociales,
sus manifestaciones, núcleos figurativos y escenarios de reincorporación identificados.
Se emplea un análisis cualitativo narrativo, utilizando 32 relatos de vida para identificar
las representaciones sociales de la violencia en ellos y su impacto en la conducta, así
como en los sistemas comunicativos de los individuos. Para esto hemos identificado tres
etapas clave: antes de ingresar a las FARC-EP, durante su permanencia en la
organización, y después la negociación y firma del Acuerdo de Paz. Además, se
examinan tres modelos de democracia en Colombia en relación con la dimensión
simbólica.
Las narrativas revelan la importancia de las representaciones sociales en los procesos de
toma de decisiones, entendidos como conductas y estructuras de comunicación. Esto abre
la discusión sobre la relevancia de incorporar dimensiones simbólicas, especialmente las
representaciones sociales, en la construcción de la paz y la democracia. En el caso
colombiano, destaca la importancia de ciertos núcleos figurativos y escenarios de
reincorporación, resaltando el “familiar” como estructura fundamental y sobresaliente. (Texto tomado de la fuente)This thesis examines the social representations of violence developed by former
members of the FARC-EP, in relation to the reintegration process arising from the 2016
Peace Agreement in Colombia. It explores the decisions made by these individuals and
the possibility of abandoning the use of weapons. Similarly, the thesis considers these
decisions as a process mediated by social representations, their manifestations, figurative
cores, and identified reintegration scenarios.
A narrative qualitative analysis is employed, using 32 life stories to identify the social
representations of violence in them and their impact on behavior, as well as on the
communicative systems of individuals. For this, we have identified three key stages:
before joining the FARC-EP, during their time in the organization, and after the
7
negotiation and signing of the Peace Agreement. Additionally, three models of
democracy in Colombia are examined in relation to the symbolic dimension.
The narratives reveal the importance of social representations in decision-making
processes, understood as behaviors and communication structures. This opens the
discussion on the relevance of incorporating symbolic dimensions, especially social
representations, in the construction of peace and democracy. In the Colombian case, the
importance of certain figurative cores and reintegration scenarios is highlighted,
emphasizing the "family" as a fundamental and prominent structure.DoctoradoPh.D. en Estudios políticos y relaciones internacionale
Democracy in the face of violence. A reflection on the social representations of political violence in Colombia through the reincorporation process of ex-guerrillas.
No full textilustraciones, diagramasEsta tesis examina las representaciones sociales de la violencia elaboradas por las y los
exguerrilleros de las FARC-EP, en relación con el proceso de reincorporación surgido
del Acuerdo de Paz en 2016 en Colombia. Explora las decisiones tomadas por estos
individuos y la posibilidad de abandonar el uso de las armas. De la misma manera la tesis
considera estas decisiones como un proceso mediado por las representaciones sociales,
sus manifestaciones, núcleos figurativos y escenarios de reincorporación identificados.
Se emplea un análisis cualitativo narrativo, utilizando 32 relatos de vida para identificar
las representaciones sociales de la violencia en ellos y su impacto en la conducta, así
como en los sistemas comunicativos de los individuos. Para esto hemos identificado tres
etapas clave: antes de ingresar a las FARC-EP, durante su permanencia en la
organización, y después la negociación y firma del Acuerdo de Paz. Además, se
examinan tres modelos de democracia en Colombia en relación con la dimensión
simbólica.
Las narrativas revelan la importancia de las representaciones sociales en los procesos de
toma de decisiones, entendidos como conductas y estructuras de comunicación. Esto abre
la discusión sobre la relevancia de incorporar dimensiones simbólicas, especialmente las
representaciones sociales, en la construcción de la paz y la democracia. En el caso
colombiano, destaca la importancia de ciertos núcleos figurativos y escenarios de
reincorporación, resaltando el “familiar” como estructura fundamental y sobresaliente. (Texto tomado de la fuente)This thesis examines the social representations of violence developed by former
members of the FARC-EP, in relation to the reintegration process arising from the 2016
Peace Agreement in Colombia. It explores the decisions made by these individuals and
the possibility of abandoning the use of weapons. Similarly, the thesis considers these
decisions as a process mediated by social representations, their manifestations, figurative
cores, and identified reintegration scenarios.
A narrative qualitative analysis is employed, using 32 life stories to identify the social
representations of violence in them and their impact on behavior, as well as on the
communicative systems of individuals. For this, we have identified three key stages:
before joining the FARC-EP, during their time in the organization, and after the
7
negotiation and signing of the Peace Agreement. Additionally, three models of
democracy in Colombia are examined in relation to the symbolic dimension.
The narratives reveal the importance of social representations in decision-making
processes, understood as behaviors and communication structures. This opens the
discussion on the relevance of incorporating symbolic dimensions, especially social
representations, in the construction of peace and democracy. In the Colombian case, the
importance of certain figurative cores and reintegration scenarios is highlighted,
emphasizing the "family" as a fundamental and prominent structure.DoctoradoPh.D. en Estudios políticos y relaciones internacionale
