Orientador: Paulina Setti Riedel / Banca: José Eduardo Zaine / Banca: Mara Lucia Marques / Resumo: A análise do meio físico feita através da avaliação de terrenos tem grande importância nos estudos da sua suscetibilidade a processos naturais, como os movimentos de massas. Este trabalho teve como objetivo avaliar duas formas de obtenção da suscetibilidade a escorregamentos aplicadas em imagens de alta resolução espacial (0,5 m) do sistema sensor GeoEye. A Análise Integrada analisa conjuntamente os elementos do terreno por meio da compartimentação fisiográfica da área. A Análise Paramétrica utiliza vários mapas temáticos, com mesma escala, para posterior sobreposição destes com aplicação de pesos definidos pelo Método AHP. A área de estudo possui 108,6 km², é um trecho da faixa de dutos ORBEL localizado no município de Duque de Caxias, e porções dos municípios de Nova Iguaçu e Belford Roxo, no estado do Rio de Janeiro. Essa região é atravessada por oleodutos e gasodutos e possui grande importância econômica. As etapas de trabalho envolveram: a caracterização da área com levantamento de dados bibliográficos; a confecção de mapas auxiliares através do Modelo Digital de Elevação, são estes os mapas Hipsométrico, de Declividade e de Formas de Vertentes, na escala 1:50.000; a elaboração do Mapa de Inventário a Escorregamentos por meio da extração das cicatrizes na imagem de Janeiro de 2010, onde foram identificadas 165 cicatrizes ao todo; o Mapa de Suscetibilidade a Escorregamento - Compartimentação Fisiográfica elaborado a partir da fotoleitura seguida da fotoanálise e fotointerpretação nas imagens GeoEye que resultou na divisão em quatro unidades fisiográficas. O Mapa de Suscetibilidade a Escorregamento - Método AHP foi gerado pela sobreposição com ponderação dos mapas auxiliares, foi utilizado o método de hierarquização pareada para a atribuição dos pesos e foram obtidas também quatro classes de suscetibilidade. A comparação dos mapas de suscetibilidade foi realizada de... / Abstract: The analysis of the environment through the terrain evaluation has a great significance in the study of its susceptibility to natural processes, such as mass movements. This research aimed the comparison between two different approaches to landslide susceptibility mapping, using GeoEye high resolution images (0.5 m). In the Integrated Analysis, the terrain elements were analyzed together through the physiographic compartmentalization. In the Parametric Analysis several thematic maps in the same scale, were combined using weights, defined by the AHP Method. The study area has 108,6 km², is a stretch of the ORBEL pipeline located in the municipality of Duque de Caxias, and portions of the municipalities of Nova Iguaçu and Belford Roxo, Rio de Janeiro State. This region is crossed by several gas and oil pipelines and has a considerable economic significance. The research steps involved: characterization of the area with the support of bibliographic data; elaboration of auxiliary maps through the Digital Elevation Model, such as the Hipsometric, Declivity and Slope Form maps, scale 1:50,000; Landslide Inventory Map, through the extraction of landslide features in the image from January 2010, with a total of 165 identified features; Landslide Susceptibility Map - Physiographic Compartmentalization elaborated from the photo-reading, photo-analysis and photointerpretation in the GeoEye images that resulted in the division into four physiographic units. The Landslide Susceptibility Map - AHP Method generated through the weighted combination of several thematic maps, it used the pairwise hierarchy method for the allocation of weights and were also obtained four susceptibility classes. The comparison between the susceptibility maps was carried out using both quantitative and descriptive analysis. It is concluded that the two approaches reached the purpose of rating the landslide susceptibility, but the Parametric Analysis showed a greater level ... / Mestre

Orientador: Alexandre César Rodrigues da Silva / Banca: Aparecido Augusto de Carvalho / Banca: Carlos Antonio Alves / Banca: José Antonio Lambert / Banca: Erinaldo Hilario Cavalcante / Resumo: O Penetrômetro Dinâmico Leve, conhecido por DPL (Dynamic Probing Light) é um equipamento portátil de sondagem geotécnica e surgiu como uma alternativa para auxiliar o ensaio SPT (Standard Penetration Test). Este é hoje um dos equipamentos de sondagem mais utilizados no mundo. Embora o DPL tenha potencial para substituir o SPT nos ensaios em solos com baixa resistência à penetração, onde o N NSP <5. Na prática é ainda pouco conhecido na área da engenharia, com aplicação de pouco destaque nas obras da construção civil. A proposta deste trabalho é instrumentar um DPL com sistema eletrônico que possa em ensaio dinâmico, medir a resistência do solo à penetração. Essa medida se deve ao trabalho da energia efetiva que impulsiona o cone do equipamento para baixo cravando-o no solo. Constatou-se que o sistema eletrônico implantado no equipamento ficou mais barato que o seu similar, os resultados dos ensaios foram gerados em menor espaço de tempo, podem ser utilizados como dados de projetos de fundações. Os sinais de força e velocidade foram produzidos nas células de carga e acelerômetro. Para obtenção desses resultados, o sistema indicou automaticamente a penetração do cone no solo, motivada pela energia envolvida no processo, que por sua vez, é resultado da integração do produto da força atuante e da velocidade das partículas (no domínio do tempo). O objetivo do trabalho foi alcançado, visto que, a instrumentação do DPL, com um sistema eletrônico, possibilitou avaliar a resistência do solo à penetração. Constatou-se que essa medida está condicionada à qualidade do sinal de força e aceleração. Esta por sua vez depende de fatores como: qualidade técnica dos sensores de deformação, construção da célula de carga, qualidade do adesivo e corretos procedimentos nos ajustes e nos ensaios com o equipamento DPL instrumentado / Abstract: The Dynamic Penetrometer Lightweight, known as, Dynamic Probing Light (DPL) is a portable geotechnical survey device, which came out, as an alternative tool to assist the Standard Penetration Test (SPT). Currently, it is one of the most used equipment all over the world. Although, the DPL has the potential for replacing the SPT in testing on soils with low penetration resistance, where the NNSP <5, it has not been known in the engineering field, applying little attention in the civil construction works. The purpose of this study is to instrument a DPL with electronics system intended to measure soil penetration resistance in dynamic test. This measure is due to the work of the effective energy that drives down the cone of the equipment, nailing it on the ground. It was found that the electronic system implemented in the equipment was cheaper than its similar, the results of the tests were generated in a shorter time and these findings can be used as data for foundation projects. The force and speed signals were produced on the load cells and accelerometer. In order to obtain these results, the system automatically indicated the penetration of the cone into the soil, caused by the energy involved in the process, which in turn, results from the integration of the active power output and speed of the particles (in the time domain). The objective of the study was reached, since the instrumentation of the DPL with an electronic system, enabled to evaluate the soil penetration resistance. It was found that this measure is subject to the quality of the force and the acceleration signal. This, in turn, depends on factors such as technical quality of strain sensors, load cell construction, quality of the adhesive and correct procedures on the adjustments, as well as, on the tests with the DPL instrumented equipment / Doutor

Orientador: Juércio Tavares de Mattos / Banca: Jairo Roberto Jiménez Rueda / Banca: Sérgio dos Anjos Ferreira Pinto / Banca: Luiz Antônio Cestaro / Banca: Luiz Eduardo de Oliveira / Resumo: Este trabalho objetiva identificar analiticamente os impactos ambientais negativos e determinar, a partir de modelos empíricos, em escala de 1:25.000, os graus de vulnerabilidade ambiental existentes no litoral sul do Estado do Rio Grande do Norte. Os resultados dos impactos foram obtidos mediante a proposição de metodologias de geoprocessamento específicas para cada impacto. A distribuição das diferentes classes de vulnerabilidade ambiental foi determinada a partir de modelamentos por álgebra de mapas. Os impactos ambientais analisados configuram-se nos campos de dunas, manguezais, faixas de praia e remanescentes florestais de Mata Atlântica. Quanto às dunas, o mapeamento indicou que 48,24% da área têm uma magnitude de impacto classificada como muito fraca. Contudo, o que preocupa é que os locais onde a magnitude do impacto é muito forte são exatamente as áreas com maior vulnerabilidade ambiental. Atualmente o maior avanço da carcinicultura ocorre em áreas que não são de manguezais, mas em sistemas ambientais associados. As faixas de praia podem se diferenciar quanto ao seu comprometimento ambiental, pois a capacidade de suporte aos impactos desses ambientes varia em função de suas características geoambientais. Apesar de os fragmentos florestais de Mata Atlântica apresentarem predominância de áreas muito irregulares (60,39%), muito pequenas (64,08%), com proporção de borda de 54,34%, má distribuição de sua densidade (setor sul) e circundados por cana-de-açúcar e áreas campestres (72,04%), eles ainda são responsáveis pelo controle geossistêmico e ecológico da área. Quanto à vulnerabilidade ambiental, verificou-se de que mais de 80% da área é classificada como de baixa e moderada vulnerabilidade. Isso mostra que, de acordo com o método aplicado e com os... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This study aims to identify analytically the negative environmental impacts and determine, based on empirical models, on a scale of 1:25,000, the existing degree of environmental vulnerability in the south coast of Rio Grande do Norte. The results of the impacts were obtained by the proposition of geoprocessing methodologies specific to each impact. The distribution of different classes of environmental vulnerability were determined from models for map algebra. The environmental impacts analyzed, are configured in the fields of dunes, mangroves, beach strips and areas of Mata Atlantica. Refering to the dunes, the mapping indicated that 48.24% of the area has a magnitude of impact rated as very small. However, the problem is that the locations where the magnitude of impact is very strong are the areas with greater environmental vulnerability. Currently the largest improvement in shrimp farming occurs in areas that are not mangrove, but in associated environmental systems.The beach strips may differ as to its environmental commitment, because the ability to support the impacts of these environments varies with geo-environmental characteristics. Although the present Mata Atlantica forest fragments shows predominance of very irregular areas (60.39%), very small (64.08%), with proportion of edge of 54.34%, bad distribution of density (southern sector) and surrounded by sugar cane fields and grassland (72.04%), they are still responsible for controlling geosystems and ecological area. Refering to the environmental vulnerability, we have concluded that more than 80% of the area is classified as low-and moderate vulnerability. This shows that, according to the method used and results achieved, most of the area is in balance. However... (Complete abstract click electronic access below) / Doutor

Seismic wave testing has become increasingly popular in site investigation. This is due to the fact that the principles involved are becoming more accepted and that the equipment are becoming more available and reliable. This dissertation presents the required theory behind one seismic test in particular, the Continuous Surface Wave (CSW) method of seismic testing. The attributes of seismic testing are presented along with a summary of various testing methods. The dissertation also demonstrates that the author developed his own system for completing this test and demonstrated that he successfully used it to measure the stiffness of two soil profiles. The author compared the stiffness as measured using the CSW method with the strength as measured using the Dynamic Cone Penetrometer (DCP) for two soil profiles, and the in situ profile was compared to a compacted profile. The author demonstrated that the in situ profile had a higher stiffness than the same soil after it was thoroughly compacted and that the DCP results concur. This was caused by the in situ profile being structured and the compacted profile not. / Dissertation (MSc)--University of Pretoria, 2006. / Civil Engineering / MSc / Unrestricted

The study of rock mass behaviour is a broad subject in the rock mechanics field which still needs more research and investigation, especially for geotechnical issues associated with dam construction. Since it is difficult to study rock mass behaviour at a large scale in the laboratory, the numerical modelling technique is an alternative method which can be used efficiently in this field. In this thesis two codes have been selected for this purpose. The first code was a continuum code FLAC (Fast Lagrangian Analysis of Continua), which was used to study the effect of a weak rock joint on the stability of a concrete gravity dam as well as to model the gravity dam with its foundation as a continuum. The second code was the Distinct Element Method (DEM) software package UDEC (Universal Distinct Element Code), which was used to study the fully jointed rock mass behaviour under the gravity dam. The equivalent strength and deformability parameters of jointed rock masses were also studied using UDEC. Furthermore, the cause of strain hardening behaviour in jointed rock samples was studied using UDEC and experimental methods. Based on UDEC models, it was concluded that only the low dip angle of the joints on downstream side, dipping upstream had a significant effect on the evaluated deformation of the dam. This was confirmed by using FLAC to model a single weak joint (using interfaces), which may exist in the upstream or downstream direction, on the stability of the dam. Furthermore, to obtain a better understanding of the rock mass behaviour, the equivalent strength parameters as well as the deformation modulus of a rock mass were determined using UDEC. A novel FISH (imbedded language in UDEC) function was developed for this purpose. A range of numerical simulations of uniaxial compressive strength (UCS) and triaxial tests were conducted on the numerical rock mass samples for these purposes. To validate this, the deformation modulus of the rock mass predicted by an analytical equation, quoted from literature, was compared with the numerical results that were given by UDEC. It was found that UDEC can efficiently be used to determine the strength and deformability parameters of rock masses and that at certain specific joint configurations, the rock mass behaviour was similar to granular material. In addition, it was concluded, for the first time, that the non-uniform distribution of axial loading on the jointed rock sample was the main cause of strain hardening especially for a joint that has a dip angle of 60 degree. To overcome this problem, a new loading configuration was developed for applying a uniform distribution of axial stress on the jointed rock samples in order to reduce the effect of platen-rock interaction on the axial stress-strain relationship, using UDEC and laboratory tests. Finally, the study of rock mass strength and deformability parameters of Surqawshan dam’s foundation in Iraq were determined using UDEC and the results were compared with rock classification systems: RMR and GSI. According to the UDEC results all methods give a similar evaluation of friction angle; however, GSI overestimates the cohesion. The UDEC and GSI gave reasonable estimations of deformation modulus, whereas RMR overestimated it. Generally, for rapid estimation of deformability and strength parameters, especially for weak sedimentary rock, the deformation modulus can be predicted from the GSI system, whereas the strength parameters can be estimated using RMR.

published_or_final_version / abstract / Applied Geosciences / Master / Master of Science

Optimization of compaction in granular material without the use of traditional ground improvement methods may be possible by optimizing the percentage of finer material and the median grain size ratio in binary soil mixtures. In this study, the median grain size ratio D50/d50 was explored as a fundamental parpmeter affecting the compaction characteristics of binary mixes made from natural sands as opposed to singular measurements such as fines content and mean grain size traditionally used to represent granular soils. A total of 18 binary granular mixes were synthetically generated from natural sands obtained from Longboat Key, Florida and evaluated through grain size analysis, laboratory compaction and determination of relative density. Results indicate that the D50/d50 ratio shows promise as a fundamental parameter for compaction optimization in binary mixes with values exceeding six approaching the densest packing configuations. / by Tara Devine Brenner. / Thesis (M.S.C.S.)--Florida Atlantic University, 2012. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.

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Evaluations of stress history and the geostatic state of stress of soils are ascertained on the basis of field geophysical measurements that provide paired complementary types of shear waves. It is well-established that multiple types of shear waves occur in the ground due to their directional and polarization properties. The shear wave velocity (Vs) provides the magnitude of small strain stiffness (G0) which depends on effective stress, void ratio, stress history, and other factors (cementation, age, saturation). Herein, this study examines a hierarchy of shear wave modes with different directions of propagation and particle motion from in-situ geophysical tests (HH, VH, and HV) and laboratory bender element data. A special compiled database from well-documented worldwide sites is assembled where full profiles of stress state, stress history, and several paired modes of Vs profiles have been obtained from crosshole tests (CHT), downhole tests (DHT), and rotary crosshole (RCHT). Reference profiles of the lateral stress coefficient (K0) are available from direct in-situ measurements (self-boring pressuremeter, hydrofracture, and push-in spade cells). Stress history is documented in terms of yield stress ratio (YSR) from consolidation testing and careful engineering geology studies. A methodology is developed that relates both the YSR and K0 to stiffness ratios obtained from directional shear wave velocities. In further efforts, means to extract reliable shear wave profiles from continuous downhole testing via a new GT autosource and seismic piezocone testing are outlined and applied to results from three test sites in Windsor/VA, Norfolk/VA, and Richmond/BC. A driving impetus to this research involves the geologic conditions at the US Dept. of Energy's Savannah River Site (SRS) in South Carolina. Here, the overburden soils in the upper 60 m depths consist of very old Miocene and Eocene sediments, primarily layered deposits of sands, clayey sands, silty sands, and interbedded clays which exhibit an apparent and unusual stress history profile. Special geologic conditions include the dissolutioning of old calcareous sediments (Santee Formation) at depths of 40 to 50 m below grade, similar to karstic limestone deposits. As a consequence, caves, voids, and infilled soft soil zones occur within the soil matrix at these elevations, probably resulting in localized collapse of the overlying soil column. Based on conventional laboratory and in-situ test data conducted during geotechnical investigations at SRS, available interpretative relationships for assessing the soil stress history and geostatic stress states show scattered and inconsistent results. Complications abound in the systematic assessments of these geomaterials due to effects of very old ageing, cementation, desiccation, and diagenesis, as evidenced by unusual in-situ shear wave velocity profiles that decrease in magnitude with depth, as measured by CHT and DHT. Based on the findings of this study, it is recommended that a new set of shear wave velocity measurements be made at SRS to obtain HH waves (and complementary VH waves) needed for an independent assessment of YSR in the upper soil column.

In this thesis, a 2D CHebyshev spectral domain decomposition method is developed for simulating the generation and propagation of internal waves over a topography. While the problem of stratified flow over topography is by no means a new one, many aspects of internal wave generation and breaking are still poorly understood. This thesis aims to reproduce certain observed features of internal waves by using a Chebyshev collation method in both spatial directions. The numerical model solves the inviscid, incomprehensible, fully non-linear, non-hydrostatic Boussinesq equations in the vorticity-streamfunction formulation. A number of important features of internal waves over topography are captured with the present model, including the onset of wave-breaking at sub-critical Froude numbers, up to the point of overturning of the pycnoclines. Density contours and wave spectra are presented for different combinations of Froude numbers, stratifications and topographic slope. / by Arjun Jagannathan. / Thesis (M.S.C.S.)--Florida Atlantic University, 2012. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.