[pt] O comportamento sísmico de taludes tem sido um tópico de grande interesse da engenharia geotécnica nos últimos 40 anos. Durante este período, a prática da engenharia nesta área evoluiu do emprego de técnicas elementares para procedimentos numéricos bastante complexos. A abordagem mais simples é a análise pseudo-estática na qual o carregamento do terremoto é simulado por uma aceleração horizontal estática equivalente atuando na massa de solo deslizante, utilizando-se um procedimento de equilíbrio limite (método das fatias), geralmente conservativo. O parâmetro que descreve o comportamento dinâmico do solo é referido como coeficiente sísmico k, e sua seleção depende fortemente da experiência e normas técnicas locais, porque não há maneira simples e segura de se escolher um valor adequado. O segundo procedimento é conhecido como método de Newmark, que envolve o cálculo de uma aceleração de escoamento, definida como a força inercial necessária para o fator de segurança atingir 1 em uma análise pseudo-estática pelo método de equilíbrio limite. O procedimento então usa os registros de aceleração do terremoto de projeto e o integra duplamente no tempo para calcular os deslocamentos permanentes acumulados. O terceiro método é referido como análise de Makdisi- Seed, que procura definir a estabilidade sísmica do talude em termos de deslocamentos aceitáveis em vez de um fator de segurança tradicional através de uma versão modificada do método de Newmark. Esta técnica apresenta uma maneira racional de calcular uma aceleração de escoamento média, necessária para produzir um valor do coeficiente de segurança do talude igual a 1. Gráficos específicos foram também desenvolvidos para estimativa dos deslocamentos permanentes, tendo sido bastante aplicados em aterros rodoviários, barragens e aterros sanitários. Finalmente, o mais sofisticado método para análise de estabilidade sísmica de taludes é conhecido como análise dinâmica, que normalmente incorpora modelos de elementos finitos e relações tensão x deformação complexas numa tentativa de obter melhores representações para o comportamento mecânico de taludes sob cargas cíclicas Os resultados destas análises podem incluir a história no tempo dos deslocamentos e tensões, bem como das freqüências naturais, efeitos de amortecimento, etc. Este trabalho apresenta uma comparação entre os métodos mencionados anteriormente, analisando o comportamento sísmico dos taludes da estrutura de contenção dos resíduos de lixiviação de minério de urânio, na Bahia, e dos taludes do bota-fora sul da mina de cobre Toquepala, situada no Peru. / [en] The seismic stability of slopes has been a topic of considerable interest in geotechnical engineering for the past 40 years. During that period, the state of practice has moved from simples techniques to more complicated numerical procedures. The simplest approach is the pseudo-static analysis in which the earthquake load is simulated by an equivalent static horizontal acceleration acting on the mass of the landslide, according to a generally conservative limit equilibrium analysis. The ground motion parameter used in a pseudo-static analysis is referred to as the seismic coefficient k, and its selection has relied heavily on engineering judgment and local code requirements because there is no simple method for determining an appropriate value. The second main procedure is known as the Newmark displacement analysis which involves the calculation of the yield acceleration, defined as the inertial force required to cause the static factor of safety to reach 1 from the traditional limit equilibrium slope stability analysis. The procedure then uses a design earthquake strong-motion record which is numerically integrated twice for the amplitude of the acceleration above the yield acceleration to calculate the cumulative displacements. These displacements are then evaluated in light of the slope material properties and the requirements of the proposed development. The third method is referred to as the Makdisi-Seed analysis sought to define seismic embankment stability in terms of acceptable deformation instead of conventional factors of safety, using a modified Newmark analysis. Their method presents a rational means to determine yield acceleration, or the average acceleration required to produce a factor of safety of unity. Design curves were developed to estimate the permanent earthquake- induced deformations of embankments, which have since been applied to sanitary landfill and highway embankments. Finally, the most sophisticated method for seismic slope stability calculations is known as the dynamic analysis, which normally incorporates a finite element model and a rather complex stress-strain behavior for geological materials in an attempt to obtain a better representation of the behavior of soils under cyclic loading. The results of the analysis can include a time history of displacements and stresses, as well as natural frequencies, effects of damping, etc. This work presents a comparison of the results obtained by the aforementioned approaches, considering the seismic behavior of the slopes of an uranium lixiviation pad situated in Bahia, Brazil, and the South embankment of the waste landfill of the Toquepala Mine, Peru.

[pt] Neste trabalho são avaliadas as condições de estabilidade do subsolo marinho ao longo da rota de um duto rígido de aço revestido com concreto, de 10 de diâmetro, localizado na Bacia de Campos, RJ. Os dados geológicos e geotécnicos foram adquiridos a partir de um amplo levantamento geofísico e geotécnico realizado na diretriz do duto. Devido as adversidades à estabilidade do fundo marinho, várias análises vêm sendo realizadas de forma qualitativa e quantitativa. Atualmente, por questões ambientais e de segurança de obras de engenharia, busca-se uma avaliação mais quantitativa dos riscos geológicos associados à condição de estabilidade do fundo marinho, pois os escorregamentos de taludes representam o principal risco para estas estruturas. As análises de estabilidade foram feitas a partir da teoria do talude infinito, em metodologia aplicada por Nowacki et al. (2003) nos campos profundos de Mad Dog e Atlantis, no Golfo do México, e comparadas com os resultados encontrados a partir da formulação clássica do talude infinito. Uma integração de dados geotécnicos e geofísicos foi necessária, para que todos os parâmetros utilizados na metodologia pudessem ser obtidos. Os resultados indicaram dois pontos críticos ao longo da rota, ambos associados aos flancos do cânion Itapemirim, que apresentam gradientes altos. Foram realizados breves estudos com o objetivo de se avaliar a possibilidade de ocorrência de mecanismos disparadores (terremotos e ondas de tempestade) nesses pontos críticos mas os resultados descartaram esta possibilidade. Concluiu- se ainda que os dados geotécnicos utilizados neste trabalho não foram suficientes e de certo modo não apropriados para a análise de estabilidade de taludes. Uma nova campanha de ensaios geotécnicos de laboratório foi proposta para futuros estudos. / [en] This research analyses stability conditions of marine sediments superficial layers of along a 10 in. diameter pipeline s route, located at Campos Basin, RJ. The geological and geotechnical data were obtained during a wide geophysical and geotechnical survey along the pipeline`s route. Due to adversities to botton stability found in the marine environment, several qualitative and quantitative stability analysis have been made. Nowadays, because of environmental and safety issues, the researches are more focused on quantitative analysis of geohazards associated with the stability condition of the sea bottom, since slope slides represent the main risk for those structures. The stability analyses were based on the infinite slope theory. The methodology applied was the same used by Nowacki et al. (2003) at the deep fields of Mad Dog and Atlantis, in the Gulf of Mexico. The results were compared with the results from the classical formulation of the infinite slope. An integration of geotechnical and geophysical data was necessary, in order to obtain all the parameters used in the methodology. The results indicated two critical points along the route, both associated with the flanks of the Itapemirim Canyon, which have steep slopes. Brief studies were made to evaluate the importance of triggering mechanisms (earthquakes and storm waves) at these critical points but the results discard this possibility. It was also concluded that the geotechnical data used in this research were insufficient and in a certain way not appropriate for the slope stability analysis. A new geotechnical lab tests campaign was proposed for future studies.

Failure of slopes adjacent to the UK transport infrastructure causes delays and these are expensive assets to repair and maintain. Understanding the processes that lead to failure will assist asset managers both now and in the future in the context of a changing climate. The EPSRC-funded multidisciplinary FUTURENET project investigated the effect of climate change on the resilience of the UK transport network and this thesis is a part of that project considering the weather patterns leading to slope failures along transport infrastructure slopes within the UK. To that end a series of slope failure case studies were investigated to understand the processes leading to failure. These were compiled using nationally held datasets as well as news reports. This research used data from the FUTURENET partners that hold national data sets and asset management information. This shows the wide reaching remit of a multidisciplinary collaborative project such as FUTURENET, but also highlights the limitations of datasets collected and used for very specific purposes and not necessarily suited to wider research. From these case studies a suite of slope failure weather thresholds were developed. These thresholds consider the antecedent period, water content within the slope through the soil moisture deficit and triggering rainfall through comparison to the long term average rainfall. Consideration was given to possible future weather using weather event sequences (WESQs), possible weather patterns for 2050 derived from the UKCP09 climate projection data. By considering these possible weather patterns with the slope failure thresholds a picture of a possible future was evaluated.

Σκοπός αυτής της Διπλωματικής εργασίας είναι η αποτύπωση της κατάστασης της κατολισθαίνουσας ζώνης στην επαρχιακή οδό Παλαιοχωρίου - Χρυσοχωρίου, στα δύο σημεία που παρατηρήθηκαν αστοχίες. Στην περιοχή αυτή πραγματοποιήθηκε αποτύπωση και χαρτογράφηση της κατολισθαίνουσας ζώνης, παρουσιάζονται τα αποτελέσματα της τεχνικογεωλογικής - γεωτεχνικής έρευνας που παρατηρήθηκαν στις δύο θέσεις αστοχίας, μετά από την μεγάλη κατολίσθηση που εκδηλώθηκε το Φεβρουάριο του 2010 από έντονες βροχοπτώσεις, καθώς και τον σχεδιασμό των μέτρων προστασίας της επαρχιακής οδού Παλαιοχωρίου -Χρυσοχωρίου. / The purpose of this essay is to capture the situation of landslide zone on provincial road Palaiochorioy - Chrysochorioy, at two failures were observed.In this area was done survey and maps of landslide zone which presents the results of geotechnical - geotechnical investigation, observed in both locations of failure, after major landslide that occurred in February 2010 after heavy rains, and the design of measures to protect the provincial road Palaiochorio-Chrysochorioy.

Seismic slope stability is often evaluated via permanent displacement analyses, which quantify the cumulative, downslope displacement of a sliding mass subjected to earthquake loading. Seismic sliding block displacements provide a useful index as to the seismic performance of a slope. Seismic sliding block displacements can be computed for a suite of acceleration-time histories selected to fit a design event. This thesis explores the effect of ground motion selection on computed seismic sliding block displacements through two approaches. First, rigid sliding block displacements were computed for ground motion suites developed to fit uniform hazard spectra (UHS), conditional mean spectra (CMS), and conditional probability distributions for peak ground velocity (PGV) and Arias Intensity (Ia). Evaluation of the suites in terms of their PGV and Ia distributions provided useful insight into the relative displacements computed for the suites. The PGV and Ia distributions of the suite selected to fit the UHS exceed the theoretical distributions of these ground motion parameters. In fact, the scaled Ia values of motions in the UHS suite are greater than the largest Ia values in the Next Generation Attenuation (NGA) ground motion database. As such, the displacements computed for the UHS suite exceed the displacements computed for any other suite. If only two ground motion parameters are to be considered in ground motion selection we recommend those parameters be PGA and PGV. However, it is important to consider PGA, PGV, and Ia when developing ground motion suites for permanent displacement analyses. Next, the use of simulated ground motions for permanent displacement analyses was addressed by comparing displacements computed for simulated ground motions to displacements computed for the corresponding recorded ground motion. Simulated ground motions generated via four seismological models were considered: the deterministic Composite Source Model (CSM), the stochastic model EXSIM, the deterministic-stochastic hybrid model by Graves and Pitarka (GP), and the deterministic-stochastic hybrid model developed at San Deigo State University (SDSU). The displacements computed for the SDSU simulations were the most similar to those computed using the recorded motions, with the average displacement of the SDSU simulations exceeding that of the corresponding recorded ground motion by about 6%. Additionally, the displacements from the SDSU simulations provided the smallest variability about the displacements computed for the recorded motions. / text

Automated technologies can be beneficial for collecting data on the condition of pavements. As opposed to a traditional manual survey of the road, automated data collection can provide a safer alternative that is objective, repeatable, and consistent, while traveling at highway speeds. Though the automated method is preferred, it still needs to be reliable enough to accurately model the current pavement performance. The Texas Department of Transportation (TxDOT) initiated a project to allow an independent assessment of the accuracy and repeatability of new automated distress data measurements. In this study, 20 550-ft. pavement sections were tested with automated data collection technologies. The sections were located in Austin and Waco Districts. The accuracy and repeatability was evaluated for cracking and other distress measurements, cross slope measurements, and texture measurements. Known manual methods were used as a reference, and a 3D system developed by TxDOT was compared with three systems of other vendors (Dynatest, Fugro, and Waylink-OSU). With the data provided for the texture and cross slope, an additional investigation was done to evaluate hydroplaning potential. This thesis reports in the latter investigation. / text

<p>The purpose of this study is to examine what affects the changes in credit spreads. A</p><p>regression model was performed where the explanatory variables were; volatility,</p><p>SP&500 index, interest-rate level the slope of yield curve and the dependent</p><p>variable was credit spread for each of CSUSDA, CSUSDBBB, and CSUSDB. We</p><p>found a positive correlation between these independent variables (Volatility, S&P</p><p>500index) and a negative correlation between interest-rate level and credit spreads.</p><p>These results were consistent with our hypothesis. However, the link between the</p><p>slope of yield curve and credit spreads was positive and that was inconsistent with</p><p>our hypothesis and some previous studies. The conclusion of this paper was a</p><p>change in credit spread is related to the variables that we used in our model. And</p><p>these variables explained about 50 per cent of this change.</p>

Acoustic emission (AE) is a natural phenomenon that occurs when a solid is subjected to stress. These emissions are produced by all materials during pre failure. In soil, AE results from the release of energy as particles undergo small strains. If these emissions can be detected, then it becomes possible to develop an early warning system to predict slope failure. International research has shown that AE can be used to detect ground deformations earlier than traditional techniques, and thus it has a role to play in reducing risk to humans, property and in mitigating such risks. This thesis researches the design of a system to quantify the AE and calculate the distance to the deformation zone, and hence information on the mechanism of movement. The quantification of AE is derived from measuring the AE event rate, the output of which takes the form of a displacement rate. This is accurate to an order of magnitude, in line with current standards for classifying slope movements The system also demonstrates great sensitivity to changes within the displacement rate by an order of magnitude, making the technique suitable to remediation monitoring. Knowledge of the position of the shear surface is critical to the planning of cost effective stabllisation measures. This thesis details the development of a single sensor source location technique used to obtain the depth of a developing or existing shear surface within a slope. The active waveguide is used to reduce attenuation by taking advantage of the relatively low attenuation of metals such as steel. A method of source location based on the analysis of Lamb wave mode arrival times at a smgle sensor is summansed. An automatic approach to source location is demonstrated to locate a regular AE source to within one metre. Overall consideration is also given to field trials and towards the production of monitoring protocols for data analysis, and the implementation of necessary emergency/remediation plans.

Let (L,h) → (X,ω) be a compact toric polarized Kahler manifold of complex dimension n. For each k ε N, the fibre-wise Hermitian metric hk on Lk induces a natural inner product on the vector space C∞(X,Lk) of smooth global sections of Lk by integration with respect to the volume form ωn /n! . The orthogonal projection Pk : C∞(X,Lk) → H0(X,Lk) onto the space H0(X,Lk) of global holomorphic sections of Lk is represented by an integral kernel Bk which is called the Bergman kernel (with parameter k ε N). The restriction ρk : X → R of the norm of Bk to the diagonal in X × X is called the density function of Bk. On a dense subset of X, we describe a method for computing the coefficients of the asymptotic expansion of ρk as k → ∞ in this toric setting. We also provide a direct proof of a result which illuminates the off-diagonal decay behaviour of toric Bergman kernels. We fix a parameter l ε N and consider the projection Pl,k from C∞(X,Lk) onto those global holomorphic sections of Lk that vanish to order at least lk along some toric submanifold of X. There exists an associated toric partial Bergman kernel Bl,k giving rise to a toric partial density function ρl,k : X → R. For such toric partial density functions, we determine new asymptotic expansions over certain subsets of X as k → ∞. Euler-Maclaurin sums and Laplace’s method are utilized as important tools for this. We discuss the case of a polarization of CPn in detail and also investigate the non-compact Bargmann-Fock model with imposed vanishing at the origin. We then discuss the relationship between the slope inequality and the asymptotics of Bergman kernels with vanishing and study how a version of Song and Zelditch’s toric localization of sums result generalizes to arbitrary polarized Kahler manifolds. Finally, we construct families of induced metrics on blow-ups of polarized Kahler manifolds. We relate those metrics to partial density functions and study their properties for a specific blow-up of Cn and CPn in more detail.

Recent attempts to elucidate a climatic effect on erosion rates at the catchment scale have generally found little or no correlation between precipitation and erosion rates, yet climate has been shown to exert a significant control on landscape properties such as drainage density, slope and relief. That erosion rates to do not directly reflect climatic conditions may not come as a surprise, since erosion rates will tend to keep pace with uplift rates in a tectonically active landscape. The interplay between erosion rates and climate may therefore be better understood with reference to the erosional efficiency of the landscape. Erosional efficiency governs how steep the landscape must become to balance uplift rates, and has also recently been postulated to affect the width to length (or spacing) ratio of first order basins, and the distribution of hillslopes within a landscape, via the relative inputs of diffusive and advective transport. This study constrains the efficiency of sediment transport along a climatic transect spanning a precipitation range of over two orders of magnitude in the Chilean Coastal Cordillera (26˚-41˚S), combining long-term erosion rates derived from concentrations of cosmogenic Be-10 in quartz in fluvial sediments with topographic metrics. The effects of changes in the relative input of diffusive and advective processes is investigated by studying the basin spacing ratios and distribution of hillslopes for a variety of natural landscapes and landscapes generated using the CHILD model. Sediment transport efficiency was found to peak at the transition between arid and semiarid climates, where herbaceous vegetation has almost entirely replaced bare ground, and to level off as climate becomes more humid, providing a background sediment transport efficiency value which will be applicable in both semi-arid and humid landscapes. Basin spacing ratios in natural landscapes show little variation along the transect, suggesting that changes in climate have little effect on this apparently universal catchment property, although maximum basin length attained appears to be linked to sediment transport efficiency. Slopes are consistently lower in the southern region where vegetation and sediment transport efficiency are uniform; here, lower slopes are maintained despite relatively high erosion rates thanks to higher sediment transport efficiency than in the north. Results from the CHILD landscapes show an increase in width to length ratio with decreasing sediment transport efficiency; this relationship is at odds with both the data from the study area and with data from previous studies. Results therefore indicate that, in natural landscapes, climate and vegetation cover exert a first order control on sediment transport efficiency. While climate and vegetation play little or no part in controlling the ratio of catchment dimensions, they may exert some control on the maximum dimensions of catchments and may help to modify the distribution of mean basin slope via their effects on hillslope processes.