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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Seismic Risk Assessment of Peruvian Public School Buildings Using FEMA P-154 Rapid Visual Screening

Cardenas, Omar, Farfan, Aaron, Huaco, Guillermo 30 September 2020 (has links)
El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / Peru is located in a high seismicity region, since is on the subduction zone between the tectonic plates of Nazca and South American, both belonging to the Pacific's Ring of Fire. Peru is a developing country, so it is of the utmost importance that the Peruvian Government is prepared to assist the thousands of casualties that may be in the face of an important seismic event. Hence seismic risk assessment of essential buildings such as schools and hospitals is necessary for structural reinforcement projects in this type of infrastructure. In this scientific article, it is shown how vulnerable the public schools of the district of San Juan de Miraflores in the city of Lima are to a seismic event. Hence FEMA P-154 Rapid Visual Screening methodology was used to assess actual condition of school infrastructure which can be used as refuge for casualties or local headquarters to emergency response. The results of the research conclude that most educational buildings present a high seismic risk and do not meet the requirements of post-earthquake use as required by the Peruvian Seismic Design Building Code.
2

Development of rapid visual screening tool for seismic evaluation of wood-frame dwellings

Lucksiri, Kraisorn 21 March 2012 (has links)
During the past several decades, earthquakes have caused extensive damage to buildings, including wood-frame, single-family dwellings, in the United States. In order to mitigate future losses, existing buildings in earthquake prone areas should be evaluated for their seismic safety. This is also an important issue for buildings in Oregon due to the Cascadia subduction zone along its west coast. One seismically vulnerable element observed in wood-frame, single-family dwellings is the shear walls. In general, assessment of shear wall seismic performance can be accomplished by a building-specific engineering calculation. Extra effort is required if the effects of plan irregularity are a concern. This project aims to facilitate seismic evaluation of wood-frame dwellings by proposing a new engineering-based rapid visual screening method to examine the expected performance level of the structure's exterior shear walls to resist lateral forces from ground motions, including torsional forces induced from plan irregularity. In order to achieve the objective, SAPWood software was used to perform a series of nonlinear time-history analyses for 480 representative models, covering different combinations of shape parameters and shear wall opening-related parameters. The evolutionary parameter hysteresis model was used to represent the load-displacement relationship of structural panel-sheathed shear walls and a ten parameter CUREE hysteresis model for gypsum wallboard sheathed walls. The calculated maximum lateral drifts were used as basic information for the development of the new method. Through the development process, the significance of both plan configuration and shear wall openings were emphasized as they affect the overall seismic performance of a building through building mass, lateral stiffnesses, and eccentricities. Within the study range, single-family dwellings with two stories, a larger percentage of openings, and having a garage door were shown to be more vulnerable to seismic events. Plan configuration and shear wall openings were important features especially in houses located in high 1 (0.5g ≤ S[subscript a] < 1.0g) and high 2 (1.0g ≤ S[subscript a] < 1.5g) seismicity regions, as they could potentially lead to severe damage. For low and moderate seismicity, the performance ranges from satisfying the collapse prevention limit to the immediate occupancy limit. The developed piRVS (plan irregularity Rapid Visual Screening) takes into consideration the shape of the floor plan, number of stories, base rectangular area, percent cutoff, and openings from doors/windows and garage doors, and supports evaluation at the immediate occupancy (IO), life safety (LS), and collapse prevention (CP) performance levels. The piRVS provides relatively more conservative assessment results than FEMA 154 and ASCE 31 Tier 1. Its prediction for the two applicable Northridge earthquake damage samples is reasonable. This method will help architects, engineers, building officials, and trained inspectors in examining the expected seismic performance of shear walls, considering the effects of plan irregularity in wood-frame, single-family dwellings / Graduation date: 2012
3

EVALUATION OF COMMON BACTERIAL BLIGHT RESISTANCE IN A RESISTANT INTER-CROSS POPULATION OF COMMON BEAN

Durham, Kelli M. 14 September 2011 (has links)
Common bacterial blight CBB, caused by Xanthomonas axonopodis pv. phaseoli, is an important disease of common bean (Phaseolus vulgaris L.). Genetic resistance is the most economically-efficient, environmentally-friendly, and socially-acceptable approach to control plant diseases including CBB. To examine the main and interaction effects of the previously-identified CBB-resistance quantitative trait loci (QTL), a resistant inter-cross population of OAC Rex and HR45 was evaluated under artificial inoculation. While the QTL on chromosome B6 of HR45 accounted for 37 to 46 % of phenotypic variation in the field, the QTL on chromosome B4 of OAC Rex was only significant in more sensitive assays using image analysis under controlled condition using a select number of lines, accounting for 15% of the variation. Broad sense heritability estimates of CBB resistance and the QTL associated with BC420 were high for severity and the area under disease progress curve, promoting the continued use of this marker in selecting CBB resistant genotypes, which in combination with SU91 marker on B8 seem to provide high levels of resistance.
4

Análisis de riesgo sísmico de colegios públicos de San Juan de Miraflores mediante la metodología de Rapid Visual Screening y evaluación del desempeño sísmico con análisis no-lineales del pabellón 780 Pre

Cardenas Angeles, Omar Percy, Farfán Bonett, Aaron Gabriel 16 January 2021 (has links)
Perú se localiza en una zona de alta sismicidad, debido a que se encuentra encima del área de subducción entre la placa tectónica de Nazca y Sudamericana, perteneciente al cinturón de fuego del Pacífico. Perú es un país en vía de desarrollo, por lo que es de suma importancia estar preparados para auxiliar a los miles de damnificados que pueda haber ante un evento sísmico importante. La evaluación del riesgo sísmico de edificaciones esenciales como colegios y hospitales es necesario para trabajos de reforzamiento estructural en este tipo de infraestructura. En el presente artículo científico, se presenta cuán vulnerables son los colegios públicos del distrito de San Juan de Miraflores en la ciudad de Lima ante un evento sísmico. Para ello, se utilizó la metodología de Inspección Visual Rápida del FEMA P-154. Además, se analizó de forma cuantitativa el pabellón 780 Pre, un módulo educativo estandarizado y construido en los años noventa cuya presencia es frecuente en dicho distrito. Para ello, se realizó un análisis no-lineal estático y no-lineal dinámico. Los resultados de la investigación concluyen que la mayoría de las edificaciones educativas presentan una alta vulnerabilidad sísmica y no cumplen con los requerimientos de uso post-sismo como se exige en la norma sismorresistente; así como también se verificó la deficiencia del módulo 780 Pre frente a un sismo severo cuando este fue sometido a los análisis no-lineales. / Peru is located in a high seismicity zone because it is set above the subduction area between the Nazca and South American tectonic plates, both belonging to the Pacific’s Ring of Fire. Being a developing country, it is of utmost importance to be prepared to help the thousands of victims that may be in the face of a major seismic event. The assessment of the seismic vulnerability of essential buildings —such as schools and hospitals— is necessary for structural reinforcement procedures in this type of infrastructure if needed. In this thesis, it is presented how vulnerable are the public schools of the district of San Juan de Miraflores in the city of Lima to a seismic event. For this, the FEMA P-154 Rapid Visual Screening methodology was used. In addition, the “780 Pre” public school building, a standardized educational building built in the 1990s and whose presence is frequent in that district, was analyzed quantitatively. For this, a static nonlinear and dynamic nonlinear analysis were performed. The results of the investigation show that most of the educational buildings present high seismic vulnerability and do not meet the requirements of post-earthquake use as required by the Peruvian seismic design provisions. Also, the deficiency of the 780 Pre building against a severe earthquake when it was subjected to non-linear analyzes was verified. / Tesis

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