No description available.

abstract: The focus of this study is statistical characterization of the significant duration of strong ground motion time histories. The significant duration is defined as the time needed to build up between five and seventy five (SD575) and ninety five percent (SD595) of the energy of a strong motion record. Energy is measured as the integral of the square of the acceleration time history and can be used to capture the potential destructiveness of an earthquake. Correlations of the geometric means of the two significant duration measures (SD575 and SD595) with source, path, and near surface site parameters have been investigated using the geometric mean of 2,690 pairs of recorded horizontal strong ground motion data from 129 earthquakes in active plate margins. These time histories correspond to moment magnitudes between 4.8 and 7.9, site to source distances up to 200 km, and near surface shear wave velocity ranging from 120 to 2250 m/s. Empirical relationships have been developed based upon the simple functional forms, and observed correlations. The coefficients of the independent variables in these empirical relationships have been determined through nonlinear regression analysis using a random effects model. It is found that significant duration measures correlate well with magnitude, site to source distance, and near surface shear wave velocity. The influence of the depth to top of rupture, depth to the shear wave velocity of 1000 m/s and the style of faulting were not found to be statistically significant. Comparison of the empirical relationship developed in this study with existing empirical relationships for the significant duration shows good agreement at intermediate magnitudes (M 6.5). However, at larger and smaller magnitude, the differences between the correlations developed in this study and those from previous studies are significant. / Dissertation/Thesis / Ph.D. Civil and Environmental Engineering 2011

abstract: As a prelude to a study on the post-liquefaction properties and structure of soil, an investigation of ground freezing as an undisturbed sampling technique was conducted to investigate the ability of this sampling technique to preserve soil structure and properties. Freezing the ground is widely regarded as an appropriate technique to recover undisturbed samples of saturated cohesionless soil for laboratory testing, despite the fact that water increases in volume when frozen. The explanation generally given for the preservation of soil structure using the freezing technique was that, as long as the freezing front advanced uni-directionally, the expanding pore water is expelled ahead of the freezing front as the front advances. However, a literature review on the transition of water to ice shows that the volume of ice expands approximately nine percent after freezing, bringing into question the hypothesized mechanism and the ability of a frozen and then thawed specimen to retain the properties and structure of the soil in situ. Bench-top models were created by pluviation of sand. The soil in the model was then saturated and subsequently frozen. Freezing was accomplished using a pan filled with alcohol and dry ice placed on the surface of the sand layer to induce a unidirectional freezing front in the sample container. Coring was used to recover frozen samples from model containers. Recovered cores were then placed in a triaxial cell, thawed, and subjected to consolidated undrained loading. The stress-strain-strength behavior of the thawed cores was compared to the behavior of specimens created in a split mold by pluviation and then saturated and sheared without freezing and thawing. The laboratory testing provide insight to the impact of freezing and thawing on the properties of cohesionless soil. / Dissertation/Thesis / M.S. Civil and Environmental Engineering 2011

Made available in DSpace on 2014-06-11T19:32:17Z (GMT). No. of bitstreams: 0 Previous issue date: 2004-04-14Bitstream added on 2014-06-13T19:02:49Z : No. of bitstreams: 1 araujo_pc_dr_rcla.pdf: 6448977 bytes, checksum: a417ef7a09cc4dcb465b4c84dfc411b9 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Os escorregamentos são os principais processos ligados à dinâmica externa, que estão em desenvolvimento nas escarpas da Serra do Mar, o que tem despertado grande interesse científico e motivado o desenvolvimento de trabalhos visando o entendimento de seus mecanismos, pois estão intimamente relacionados a situações de risco. Contemplando as mais variadas formas de abordagens, os trabalhos desenvolvidos nessa região tem um ponto em comum: As análises, em sua grande maioria, são feitas através de modelos analógicos, que utilizam medidas diretas e apresentam resultados qualitativos. No presente trabalho, apresenta-se uma abordagem quantitativa que utiliza recursos da geotecnologia para gerar mapas de suscetibilidade a escorregamentos através do método pesos das evidências (WOFE), baseado em probabilidade condicional ou Bayesiana. Esse método é utilizado para medir as relações espaciais entre eventos já ocorridos e os mapas de evidências associados aos condicionantes desses eventos. Um pressuposto importante desse método é a independência condicional entre as evidências, sendo sua avaliação feita através dos métodos estatísticos qui-quadrado e teste global. O método proposto foi aplicado em uma área do Município de São Sebastião, litoral norte do Estado de São Paulo, utilizando mapas com padrões binários. A obtenção dos mapas binários obedeceu ao critério de contraste máximo, que é a medida de correlação espacial entre os escorregamentos e as evidências. A avaliação dos resultados obtidos indica que a abordagem utilizada apresenta potencial para aplicação em estudos sobre suscetibilidade a escorregamentos e avaliações sobre risco, em função do uso de probabilidade condicional. / Landslide is the main process linked to external dynamic that take place in the Mar Mountain Range (Serra do Mar) escarpments. It has been of great scientific interest and has motivated researches that aim the comprehension of its mechanisms. The approaches have been diversified, but with a common sense: the analyses are mainly made through analogical models, using direct measurements and showing qualitative results. Alternatively, this work shows a quantitative approach, using geotechnology resorts that give raise to landslides susceptibility maps through the weights of evidence method (WOFE). This method, based in the conditional or bayesian probability, is useful to measure the spatial correlations among events and evidence maps, which are selected as factors that influence the occurrence of these events. The conditional independence between the evidence maps is an important purpose of the WOFE method, and the evaluation is made through the overall test and chi-square statistic methods. The method was applied in an area of the São Sebastião County, in the North Coast of the São Paulo State, Brazil, using binary maps. The binary maps were the result of the reclassification using the maximum contrast criterion, which is the measurement of the spatial correlation between landslides and evidences. The evaluation of the results show that the approach presents potential for application in studies on landslide susceptibility and evaluations on risk, based of the use of conditional probability.

Orientador: Paulina Setti Riedel / Banca: Ardemirio de Barros Silva / Banca: Arlei Benedito Macedo / Banca: Ricardo Vedovello / Banca: Iandara Alves Mendes / Resumo: Os escorregamentos são os principais processos ligados à dinâmica externa, que estão em desenvolvimento nas escarpas da Serra do Mar, o que tem despertado grande interesse científico e motivado o desenvolvimento de trabalhos visando o entendimento de seus mecanismos, pois estão intimamente relacionados a situações de risco. Contemplando as mais variadas formas de abordagens, os trabalhos desenvolvidos nessa região tem um ponto em comum: As análises, em sua grande maioria, são feitas através de modelos analógicos, que utilizam medidas diretas e apresentam resultados qualitativos. No presente trabalho, apresenta-se uma abordagem quantitativa que utiliza recursos da geotecnologia para gerar mapas de suscetibilidade a escorregamentos através do método "pesos das evidências" (WOFE), baseado em probabilidade condicional ou Bayesiana. Esse método é utilizado para medir as relações espaciais entre eventos já ocorridos e os mapas de evidências associados aos condicionantes desses eventos. Um pressuposto importante desse método é a independência condicional entre as evidências, sendo sua avaliação feita através dos métodos estatísticos qui-quadrado e teste global. O método proposto foi aplicado em uma área do Município de São Sebastião, litoral norte do Estado de São Paulo, utilizando mapas com padrões binários. A obtenção dos mapas binários obedeceu ao critério de contraste máximo, que é a medida de correlação espacial entre os escorregamentos e as evidências. A avaliação dos resultados obtidos indica que a abordagem utilizada apresenta potencial para aplicação em estudos sobre suscetibilidade a escorregamentos e avaliações sobre risco, em função do uso de probabilidade condicional. / Abstract: Landslide is the main process linked to external dynamic that take place in the Mar Mountain Range (Serra do Mar) escarpments. It has been of great scientific interest and has motivated researches that aim the comprehension of its mechanisms. The approaches have been diversified, but with a common sense: the analyses are mainly made through analogical models, using direct measurements and showing qualitative results. Alternatively, this work shows a quantitative approach, using geotechnology resorts that give raise to landslides susceptibility maps through the "weights of evidence" method (WOFE). This method, based in the conditional or bayesian probability, is useful to measure the spatial correlations among events and evidence maps, which are selected as factors that influence the occurrence of these events. The conditional independence between the evidence maps is an important purpose of the WOFE method, and the evaluation is made through the overall test and chi-square statistic methods. The method was applied in an area of the São Sebastião County, in the North Coast of the São Paulo State, Brazil, using binary maps. The binary maps were the result of the reclassification using the maximum contrast criterion, which is the measurement of the spatial correlation between landslides and evidences. The evaluation of the results show that the approach presents potential for application in studies on landslide susceptibility and evaluations on risk, based of the use of conditional probability. / Doutor

The purpose of the present qualitative multiple case study was to identify and describe sustainability efforts and the perceptions of sustainability managers of selected higher education institutions (HEIs) in Texas. Through a Qualtrics survey and semi-structured interviews, sustainability managers shared their experiences regarding the implementation of sustainable initiatives on their campuses. The present study identified four broad themes including Organizational and Leadership Challenges and the Impact They Can Have on Sustainability, Facilities Challenges and Their Impact on Sustainability, Issues with Full Buy-In on the Part of Stakeholders, and Sustainability Personnel Knowledge and Experience. The results of the present study are considered, and recommendations are provided to help researchers identify challenges to implementing sustainability initiatives on HEI campuses.

The dielectric properties and emissivity of several types of sea ice were studied to improve upon the currently available algorithms for intepreting polar radiometric imagery from the SSM/I sensor. Laboratory studies indicated that the relative dielectric constant of new sea ice, as measured with a spectral C-Band radiometer, is approximately 12. This value represents the early stages of ice formation, and decreases rapidly with ice growth to approach the accepted value of 3.2 for first year ice. Atmospheric effects on satellite based passive microwave data were also examined with regard to the 19, 22, 37, and 85 GHz channels of the SSM/I system. The atmospheric vapor and cloud liquid water attenuation was empirically modeled with respect to frequency and atmospheric temperature. The mean atmospheric temperature was empirically linked to surface temperature through an exponential relationship. The surface emissivity was then modelled as a function of surface type via a mixing formalism, where the emissivity of open water depends on surface wind-speed. With the significant environmental variables parameterized, two algorithms for analysis of polar SSM/I data were developed. The first is a simple modification that adds the capability of determining ice temperature to an existing algorithm. The second is a weather correcting algorithm significantly more complex than those currently in use for the lower three frequencies of the Special Sensor Microwave Imager (SSM/I). The uncertainty of the six products due to measurement noise was estimated at 5% for surface parameters and 10% for atmospheric variables. The atmospheric vapor and cloud liquid water estimates are used to convert the raw 85 GHz brightness temperatures to surface brightness temperature estimates, producing a significantly enhanced ice edge.

No description available.

Orientador: Sérgio Campos / Banca: Lincoln Gehring Cardoso / Banca: Fernanda Leite Ribeiro / Banca: Yara Manfrin Garcia / Banca: Rafael Calore Nardini / Resumo: O Zoneamento Ecológico-Econômico (ZEE) está inserido na Política Nacional do Meio Ambiente e tem sido importante para implantação de políticas públicas em municípios atuando no ordenamento territorial em busca do desenvolvimento sustentável. O objetivo do presente estudo foi realizar uma proposta de ZEE que subsidiasse um plano de gestão ambiental para o município. A área de estudo é o município de Barra Bonita, está localizada na porção central do Estado de São Paulo e possui uma área de 15.208,97 hectares. Com o auxilio das imagens de satélite Sentinel-2A do ano de 2017 e ferramentas do Sistema de Informação Geográfica (SIG) QGIS, gerou-se mapas dos componentes da paisagem, como solo, declividade, recursos hídricos, uso e ocupação da terra e APPs. As metodologias utilizadas foram propostas por Ross (1994), sobre as unidades ecodinâmicas e na análise empírica da fragilidade ambiental. Com base no mapeamento do uso e ocupação da terra, constatou-se que 72,72% da área de estudo estão destinadas ao cultivo da cana-de-açúcar, seguido da classe mata 8,75% e o restante distribuído em área urbana, e outras classes. As fragilidades ambientais foram analisadas resultando em Fragilidade Potencial "Muito Baixa" (44,98%) seguida de "Baixa" (31,25%) e para Fragilidade Emergente "Média" (64,58%) e "Forte" (18,53%). O levantamento das fragilidades permitiu definir as áreas mais frágeis que merecem mais atenção e estabelecer as zonas com suas respectivas unidades que representam o Zoneament... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The Ecological-Economic Zoning (EEZ) is an instrument of the National Environmental Policy and has been important for the implementation of public policies in municipality acting in the territorial order in search of sustainable development. The objective of the present study was to carry out a proposal of Ecological-Economic Zoning that subsidized an environmental management plan for the municipality. The area of study is the municipality of Barra Bonita, which is located in the central portion of the State of São Paulo and has an area of 15.208,97 hectares. With the help of the Sentinel-2A satellite images from the year 2017 and the tools of the Geographic Information System (GIS) QGIS generated maps of landscape components, such as soil, slope, water resources, land use and occupation, and PPAs. The methodologies used were proposed by Ross (1994), about ecodynamic units and an empirical analysis of the environmental fragility. Based on the mapping of land use and occupation, it was verified that 72.72% of the study area is destined to the cultivation of sugarcane, followed by the class forest 8.75%, and the rest distributed in urban area and other classes. Environmental fragilities were analyzed resulting in "Very Low" Potential Fragility, followed by "Low" and for "Medium and Strong" Emergent Fragility. The survey of fragilities allowed to define the most fragile areas that deserve more attention and establish ... / Doutor

Este estudo foi realizado em uma clareira, um fragmento de Mata Atlântica de 4,8 hectares localizado no município de São Sebastião - SP, de propriedade da Universidade São Marcos, com o objetivo de fornecer subsídios sobre as atividades de sua recomposição vegetal, de modo que possa prevenir e/ou reduzir os riscos de escorregamentos na encosta. As metodologias disponíveis e mais adequadas para diagnóstico de áreas frágeis e com risco de escorregamento foram expressas em cartas geotécnicas. Outro aspecto metodológico que mereceu destaque refere-se à análise dos elementos (fisiográficos e antrópicos) que compõem o terreno analisado. Para a etapa de compartimentação do terreno existem duas abordagens básicas: a paramétrica e a fisiográfica. Na primeira foram feitas associações de temas representados em mapas específicos (por exemplo, mapas de relevo, geológico, geomorfológico). A abordagem fisiográfica foi avaliada quanto a suscetibilidade à ocorrência de movimentos de massa. A modelagem para o reflorestamento é o plantio heterogêneo, que consiste na prática de se plantar o conjunto de diferentes espécies numa mesma área, recriando condições, mais próximos possível da mata atual. Assim, foi realizado um levantamento fitossociológico no fragmento de entorno da clareira à fim de subsidiar a seleção de espécies para a recomposição vegetal. A seleção de espécies (50% de crescimento rápido) foi feita visando a interrupção do processo de erosão e, conseqüentemente, como medida de prevenção ao escorregamento da encosta. Com a proposta aqui realizada pretende-se ainda que, o modelo resulte como potencial de extrapolação para outras áreas de floresta ombrófila densa de encosta. / This study was carried out in an opening, a 4.8 hectares fragment of Mata Atlântica located in the municipality of São Sebastião-SP and owned by the University São Marcos, with the goal of providing subsidies about the vegetation renewal activities in such a way that the risk of hillside sliding can be avoided. The available and most appropriate methodologies for the diagnosis of fragile areas with a sliding risk were explained in the geotechnical charters. Another note-worthy methodological aspect is the analysis of the elements (physiographical and anthropic) which are part of the analyzed terrain. There are two basic approaches for the compartmentalization phase of the terrain: the parametric and the physiographic. In the first, the correspondence of topics represented in specific maps (for example, relief, geological and geomorphological maps) was made. The physiographic approach was evaluated for its susceptibility to the occurrence of mass movements. The modeling for the reforestation is heterogeneous planting, which consists in planting a set of different species in the same area, recreating conditions most like the current vegetation. Thus, a phytosociological survey was carried out in the fragment surrounding the opening in order to give subsidies for the selection of species for plant renewal. The species were selected (50% rapid growing species) with the goal of interrupting the erosion process and, as a result, as preventive measure against hillside sliding. The intention is this proposal can be has potential to be extrapolated to other dense ombrophylous forests in cliffs.