abstract: I investigate the Black Canyon City landslide (BCC landslide), a prominent deep-seated landslide located northeast of Black Canyon City, Arizona. Although the landslide does not appear to pose a significant hazard to structures, its prominent features and high topographic relief make it an excellent site to study the geologic setting under which such features develop. This study has the potential to contribute toward understanding the landscape evolution in similar geologic and topographic settings, and for characterizing the underlying structural processes of this deep-seated feature. We use field and remotely-based surface geology and geomorphological mapping to characterize the landslide geometry and its surface displacement. We use the Structure from Motion (SfM) method to generate a 0.2 m resolution digital elevation model and rectified ortho-photo imagery from unmanned aerial vehicle (UAV) - and balloon-based images and used them as the base map for our mapping. The ~0.6 km2 landslide is easily identified through remotely-sensed imagery and in the field because of the prominent east-west trending fractures defining its upper extensional portion. The landslide displaces a series of Early and Middle Miocene volcanic and sedimentary rocks. The main head scarp is ~600 m long and oriented E-W with some NW-SE oriented minor scarps. Numerous fractures varying from millimeters to meters in opening were identified throughout the landslide body (mostly with longitudinal orientation). The occurrence of a distinctive layer of dark reddish basalt presents a key displaced marker to estimate the long-term deformation of the slide mass. Using this marker, the total vertical displacement is estimated to be ~70 m, with maximum movement of ~95 m to the SE. This study indicates that the landslide motion is translational with a slight rotational character. We estimate the rate of the slide motion by resurvey of monuments on and off the slide, and examination of disturbed vegetation located along the fractures. The analysis indicates a slow integrated average landslide velocity of 10-60 mm/yr. The slide motion is probably driven during annual wet periods when increased saturation of the slide mass weakens the basal slip surface and the overall mass of the slide is increased. Results from our study suggest that the slide is stable and does not pose significant hazard for the surrounding area given no extreme changes in the environmental condition. Although the landslide is categorized as very slow (according to Cruden and Varnes, 1996), monitoring the landslide is still necessary. / Dissertation/Thesis / Masters Thesis Geological Sciences 2016

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第21950号 / 理博第4528号 / 新制||理||1650(附属図書館) / 京都大学大学院理学研究科地球惑星科学専攻 / (主査)教授 釜井 俊孝, 教授 千木良 雅弘 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

Tsunami are a very dangerous natural hazard, as highlighted in recent years by the Indian Ocean Tsunami of 2004 and the Japan Tsunami of 2011. In the last decade, tsunami have claimed hundreds of thousands of lives, and caused billions of dollars in damage around the world. The hazard posed to coastal communities by tsunami is expected to increase in the future, due to population growth, intensification of coastal development and sea level rise due to climate change. Tsunami may be generated by a number of different source mechanisms. One such source mechanism is a submarine landslide, which can occur in a number of marine environments containing significant sediment accumulation on a sloping seafloor. The high amplitudes and rapid celerities of landslide-generated tsunami make them very dangerous to communities in the vicinity of the landslide, although these waves do not possess the potential for transoceanic devastation. The objectives of this research project are to carry out a series of two-dimensional physical experiments investigating the waves generated by a rigid block landslide moving along a horizontal boundary. The use of a horizontal boundary has the advantage that waves propagating in the offshore and onshore directions may be measured (unlike previous studies using sloping boundaries). The landslide motion is provided by a mechanical system, allowing testing of a broad range of motion, and isolation of the wavemaking properties of different phases of landslide motion. Experiments are carried out in a 14.66 m long flume, with width 0.25 m and working depth 0.50 m. A false floor installed in the flume provides the sliding surface for the landslide motion, and houses the mechanical system. A series of preliminary particle tracking velocimetry experiments confirm the ability of the mechanical system to achieve its velocity targets to within 5% or better, depending on the parameters of the landslide motion. Full spatial and temporal resolution of the wave field is achieved using a laser-induced fluorescence technique to identify the air-water interface to sub-pixel accuracy. The measurements obtained using laser-induced fluorescence are validated against measurements from a resistance wave gauge, with sub-millimetre agreement. In an additional experiment, the particle tracking velocimetry technique provides measurements of the subsurface velocity field. The landslide motion during all experiments consists of an initial period of constant acceleration, followed by a period of constant velocity, followed by a deceleration to rest (at the same rate as the initial acceleration). The landslide acceleration generates two dispersive packets of waves, travelling in the offshore and onshore directions. The offshore-propagating wave packet contains a leading crest and the onshore-propagating wave packet contains a leading trough, with both waves approaching the shallow water limit. A free surface depression forms above the landslide during its constant-velocity motion, and its amplitude may be predicted to within approximately 20% using standard hydraulic theory (considering a frame of reference moving with the landslide). The offshore-propagating waves passing over the landslide cause the amplitude of this depression to fluctuate over time. The deceleration of the landslide generates two additional packets of waves with the opposite polarity to the waves generated by the landslide acceleration. The full spatial and temporal resolution of the generated wave field allows the calculation of the potential energy within the wave field. Additionally, the energy (and mass) within the onshore- and offshore-propagating wave packets may be estimated by calculating these quantities within the onshore and offshore regions of the experimental domain. The wave packets generated by the initial landslide acceleration transport positive mass in the offshore direction, and negative mass in the onshore direction. This mass transport is balanced by the waves generated during the deceleration of the landslide. The nondimensional landslide acceleration, landslide Froude number and submergence depth are varied during the physical experiments. The landslide Froude number has the greatest effect on the behaviour of the generated wave field. At low Froude numbers, the wave field is dominated by the waves generated by the acceleration and deceleration of the landslide. As the Froude number increases, the onshore-propagating waves become negligible in amplitude compared to the offshore-propagating waves. Additionally, the free surface depression increases in amplitude and a group of short-wavelength waves become trapped behind the landslide. These waves exhibit highly nonlinear behaviour at landslide Froude numbers greater than 0.5. The simple experimental geometry allows comparison between the measured wave fields with the predictions of three mathematical models. Two inviscid-irrotational models, differing in their treatment of the bottom boundary condition, provide comparisons over the entire parameter space. These models under-predict the amplitudes of the generated waves, and fail to correctly predict the ongoing interaction between the landslide and the offshore-propagating waves. The inclusion of bottom boundary nonlinearity improves the predictions of the amplitude of the leading waves, and the potential energy within the wave field. However, both of the inviscid models do not predict the extent of wave trapping behaviour behind the landslide observed in the experiments. A viscous model, formulated in the DNS solver Gerris, improves the predictions of wave trapping (and amplitude in general) in one experiment. Although the model still under-predicts the amplitudes of the generated waves, it correctly predicts the amplification of the waves behind the landslide during its constant-velocity motion. The failure of the inviscid models to predict the amplitudes of these waves can be mostly attributed to the linearised free surface condition used by both models. The presence of the turbulent wake may also have a secondary effect on these predictions. An extension of the linear inviscid-irrotational model to three dimensions allows the effect of the landslide width on the amplitudes of the generated waves to be determined. As the width increases, the behaviour of the waves approaches the two-dimensional limiting case.

Quantitative risk assessments are a fundamental part of economic analysis and natural hazard risk management models. It increases the objectivity and the transparency of risk assessments and guides policymakers in making efficient decisions when spending public resources on risk reduction. Managing hazard risks calls for an understanding of the relationships between hazard exposure and vulnerability of humans and assets.   The purpose of this thesis is to identify and estimate causal relationships between hazards, exposure and vulnerability, and to evaluate the applicability of systematically collected data sets to produce reliable and generalizable quantitative information for decision support.   Several causal relationships have been established. For example, the extent of lake flood damage to residential buildings depends on the duration of floods, distance to waterfront, the age of the house and in some cases the water level. Results also show that homeowners private initiative to reduce risk, prior to or during a flood, reduced their probability of suffering building damage with as much as 40 percent. Further, a causal relationship has been established between the number of people exposed to quick clay landslides and landslide fatalities.   Even though several relationships were identified between flood exposure and vulnerability, the effects can only explain small parts of the total variation in damages, especially at object level. The availability of damage data in Sweden is generally low. The most comprehensive damage data sets in Sweden are held by private insurance companies and are not publicly available. Data scarcity is a barrier to quantitative natural hazard risk assessment in Sweden. More efforts should therefore be made to collect data systematically for modelling and validating standardized approaches to quantitative damage estimation. / Natural hazard damages have increased worldwide. Impacts caused by hydrological and meteorological hazards have increased the most. An analysis of insurance payments in Sweden showed that flood damages have been increasing in Sweden as well. With climate change and increasing populations we can expect this trend to continue unless efforts are made to reduce risk and adapt communities to the threats. Economic analysis and quantitative risk assessments of natural hazards are fundamental parts of a risk management process that can support policymakers' decisions on efficient risk reduction. However, in order to develop reliable damage estimation models knowledge is needed of the relationships between hazard exposure and the vulnerability of exposed objects and persons. This thesis has established causal relationships between residential exposure and flood damage on the basis of insurance data. I also found that private damage-reducing actions decreased the probability of damage to buildings with almost 40 percent. Further, a causal relationship has been established between the number of people exposed to quick clay landslides and fatalities. Even though several relationships have been identified between flood exposure and vulnerability, the effects can explain only small parts of the total variation in damages, especially at object level, and more effort is needed to develop quantitative models for risk assessment purposes.

Fluid structure interactions in the presence of a free surface includes complex phenomena, such as slamming, air entrainment, transient loads, complex free surface profiles and turbulence. Hence, an appropriate and efficient numerical method is required to deal with these type of problems (efficient both in problem setup and numerical solution). Eulerian mesh-based methods can be used to solve different types of problems, however they have difficulties in problems involving moving boundaries and discontinuities (e.g. fluid structure interactions in the presence of a free surface). Smoothed Particle Hydrodynamics (SPH) is a mesh-less Lagrangian particle method, ideal for solving problems with large deformation and fragmentation such as complex free surface flows. The SPH method was originally invented to study astrophysical applications and requires modifications in order to be applied for hydrodynamic applications. Applying solid boundary conditions for hydrodynamic applications in SPH is a key difference to the original SPH developed for astrophysics. There are several methods available in literature to apply solid boundaries in SPH. In this research, an accurate solid boundary condition is used to calculate the pressure at the boundary particles based on the surrounding fluid particles. The two main methods to calculate the pressure in the SPH method are the weakly compressible SPH (WCSPH) and the incompressible SPH (ISPH) approaches. The WCSPH uses the equation of state while ISPH solves Poisson's equation to determine the pressure. In this dissertation, an explicit incompressible SPH (ISPH) method is used to study nonlinear free surface applications. In the explicit ISPH method, Poisson's equation is explicitly solved to calculate the pressure within a projection based algorithm. This method does not require solving a set of algebraic equations for pressure at each time step unlike the implicit method. Here, an accurate boundary condition along with an accurate source term for Poisson's equation is used within the explicit method. Also, the sub-particle turbulent calculation is applied to the explicit ISPH method (which handles large-scale turbulent structures implicitly) in order to calculate the flow field quantities and consequently forces on the device more accurately. The SPH method is typically computationally more expensive than Eulerian-based CFD methods. Therefore, parallelization methods are required to improve the performance of the method, especially for 3D simulations. In this dissertation, two novel parallel schemes are developed based on Open Multi Processing (OpenMP) and Message Passing Interface (MPI) standards. The explicit ISPH approach is an advantage for parallel computing but our proposed method could also be applied to the WCSPH or implicit ISPH. The proposed SPH model is used to simulate and analyze several nonlinear free surface problems. First, the proposed explicit ISPH method is used to simulate a transient wave overtopping on a horizontal deck. Second, a wave impacting on a scaled oscillating wave surge converter (OWSC) is simulated and studied. Third, the performance and accuracy of the code is tested for a dam-break impacting on tall and short structures. Forth, the hydrodynamic loads from the spar of a scaled self-reacting point absorber wave energy converter (WEC) design is studied. Finally, a comprehensive set of landslide generated waves are modeled and analyzed and a new technique is proposed to calculate the motion of a slide on an inclined ramp implicitly without using a prescribed motion. / Graduate

The volcanic island of Fogo belongs to the Cape Verde archipelago, a two-tiered chain of islands situated 500 km west of the African coast. Fogo is regarded as one of the most active volcanoes in the world with 10 eruptions during the last 250 years. The former shield volcano Monte Amarelo reached 3500 m.a.s.l. before it collapsed into the Atlantic Ocean. The massive landslide event occurred between 124 and 86 ka, forming the Bordeira cliffs and the high plateau Cha das Caldeiras on Fogo. We have collected rock samples from the Bordeira dikes, which intruded into the Bordeira wall prior to collapse. The purpose of the project is to produce a magmatic storage model for Fogo using mineral chemistry and thermobarometric methods. Additionally, I aim to determine the processes prevailing in the magmatic system, the link between the volcanic and plutonic system. Previous studies on the magma storage beneath Fogo have focused on the volcanics, which show crystallization pressures between 0.45 to 0.68 GPa using clinopyroxene-melt thermobarometry on rims. The Bordeira dikes are basanitic to nephelinitic in composition. The mineral assemblage of the 20 dike samples consist of phenocrystic clinopyroxene ± olivine ± plagioclase ± xenocrystic amphibole. Accessory minerals are titanomagnetite, apatite, nepheline, plagioclase and alkali feldspar in a microcrystalline groundmass. Clinopyroxene displays a large compositional variation, ranging from Mg#38 to Mg#85, with a mean of Mg#71±10 2s.d. (n=614). Xenocrystic amphibole varies from Mg#37 to Mg#72, with a mean of Mg#62±15 2s.d. (n=78). Interstitial feldspar forms two groups, one of An#24 to An#79, with a mean of An#66±19 2s.d., (n=125) and a second with Or#19 to 100 with a mean of Or#69±42 2s.d.(n=71). Bulk geochemistry of the 20 samples range from 1.82 to 11.5 MgO wt%. Our clinopyroxene-melt thermobarometry show crystallization pressures ranging from 0.02 to 0.85 GPa, with a mean of 0.47±0.29 2s.d. (n=502) (Putirka et al. 2003). Structural data from the intrusive dikes in the Bordeira contain three preferred orientations, N-S, NW-SE and E-W (n=371). The main process occurring in the magmatic system is fractional crystallization, however there is some evidence for phenocryst accumulation and magma recharge. Our magma storage model show that clinopyroxene crystallization initiates in the lithospheric mantle, between 15 to 28 km depth. Significant clinopyroxene rim and microcryst crystallization occur above Moho, between 9 to 12 km, implying that magma storage levels do exist in the oceanic crust. The intrusive and extrusive rocks present on Fogo show common storage levels, suggesting that they are formed in the same system but the difference being their residence time in the crustal level storage. Our structural data and 3D model suggest that the Monte Amarelo rift zone was composed of three components, being oriented NW-SE, N-NE and E-W. The flank collapse was caused by dike intrusions of N-S orientation which enabled a E-W extension of the shield volcano. / Vulkanön Fogo är en del av ögruppen Kap Verde i Atlanten. Ögruppen bildar en två delad arkipelag positionerad 500 km väster om det afrikanska fastlandet. Ön, tillika vulkanen Fogo har på senare tid varit en av de mest aktiva vulkanerna i världen med 10 utbrott under de senaste 250 åren. Ön byggdes upp av sköldvulkanen Monte Amarelo nådde 3500 m ö h innan delar av den kollapsade ned i Atlanten. Det massiva skredet som skedde mellan 86 och 124 tusen år sedan skapade högplatån Cha das Caldeiras samt den omringande klippsektionen Bordeira. Vi har samlat stenprover från de plutoniska bergarter som har trängt in sig i klippsektionen Bordeira. Målet med vår studie är att skapa en modell för hur magma lagringen fungerar under Fogo. Vi ämnar kartlägga magmalagringsdjupet med hjälp av kemiska variation i mineral som kan användas för att kartlägga kristalliseringstryck och temperatur som i t.ex. klinopyroxen. Vi är samtidigt intresserade av att veta vilka processer som sker i det magmatiska systemet och sambandet mellan vulkanska bergarter t.ex. lava och plutoniska bergarter. Tidigare studier av Fogos magmalagring har använt vulkaniska bergarter, som kristalliserar sig mellan 0.45 till 0.68 GPa när man undersökt kemin på kristallkanter av klinopyroxen. 20 prover har analyserats från Bordeiraklipporna och de innehåller låga kiselhalter, mellan 37 till 47% samt höga mängder alkaliska oxider så som kalium och natrium. Provernas mineralinnehåll består främst av större kristaller av silikatmineralen klinopyroxen ± olivin± fältspat ± främmande amfibolkristaller. De större kristallerna är omringande av en mikrokristallin grundmassa bestående av järn-titanoxider, apatit och fältspatoider. Klinopyroxen har en relativt stor kemisk variation, med Mg#37 till Mg#85, med ett medelvärde på Mg#71. Vi har även två olika sorter av fältspat, en grupp med ett kalciumrik rikt innehåll klassificeras som anortit, och en annan med ett kaliumrikt innehåll, som ortoklas. Vår analys av klinopyroxen-smälta har gett oss kristalliseringstryck som sträcker sig mellan 0.02 till 0.85 GPa med ett medelvärde på 0.47 GPa. Detta innebär att den dominerande processen i magmalagringssystemet är fraktionerad kristallisering då vi kan se ett linjärt avtagande för många ämnen när de jämförs mot magnesiumhalten. Vår magmalagringsmodell för vulkanen Fogo visar att klinopyroxenkrystallisering påbörjas i den litosfäriska manteln, mellan 15 och 28 km djup. Kristallisering av kanter på klinopyroxenkristaller samt mindre kristaller i grundmassan sker ytligare och visar på att det finns en eller flera magmalagringsnivåer i den oceaniska jordskorpan, mellan 9 till 12 km djup. Vulkaniska och plutoniska bergarter vittnar om ett delat magmasystem, vilket indikerar att skillnaden mellan de två bergarterna främst är tiden de befinner sig på respektive lagringsnivå. Vår strukturgeologiska data samt 3D modell visar att den intrusiva aktiviteten var primärt orienterad NV-SO, N-NO och O-Vriktning. Monte Amarelo-vulkanens skred och kollaps orsakades av intruderande gångar med en generell N-S orientering vilket ledde till ett skred på östsidan.

Este trabalho apresenta uma revisão bibliográfica sobre procedimentos de estudos sobre escorregamento, com enfoque para as metodologias de previsão a partir da combinação de conhecimentos de modelagem hidrológica e análise determinística tendo como base a avaliação do fator de segurança 3D. Foi desenvolvido um conjunto de procedimentos que permitam a previsão de escorregamentos em escalas maiores que 1:10.000 e estes foram aplicados em oito áreas na cidade de Campos do Jordão (SP). Os resultados obtidos para estas áreas são bastante promissores e refletiram as condições geológicas, geotécnicas e hidrogeológicas de cada área. / This work presents a review of procedures for landslides studies, with focus on the methodologies of forecasting from the combination of knowledge of hydrological modeling and analysis based on deterministic evaluation of the 3D factor of safety. It was developed a set of procedures for the prediction of landslides on scales larger than 1:10,000, and these were applied in eight areas in the city of Campos do Jordão (SP). The results for these areas are very promising and reflected the geological, geotechnical and hydrogeological conditions in each area.

Diante de tantas crises e catástrofes ocorridas nos últimos anos, relacionadas a eventos extremos de precipitação, que muitas vezes resultam em graves prejuízos materiais e, sobretudo, em perda de vidas humanas; a discussão sobre os riscos socioambientais ganha outra dimensão. O atual modelo de desenvolvimento caracteriza-se pela banalização do risco, haja vista que a produção incessante de riquezas atrela-se à produção de um número cada vez maior de contextos vulneráveis, sobretudo em áreas de grande pobreza - onde a capacidade de resposta aos diferentes impactos é bastante reduzida. No ambiente urbano, o problema é ainda mais evidenciado, pela grande extensão das áreas ocupadas por assentamentos precários. As mudanças microclimáticas observadas nas grandes metrópoles, bem como os cenários apresentados pelo Painel Intergovernamental de Mudança do Clima, apontam a necessidade do desenvolvimento de medidas que visem ao gerenciamento adequado de riscos relacionados a eventos extremos, uma vez que estes podem se tornar mais frequentes e intensos nas próximas décadas. Este trabalho procura realizar uma análise multidimensional da vulnerabilidade do município de São Paulo frente a processos relacionados a chuvas intensas, em especial os escorregamentos de vertentes. Pretende apontar no espaço paulistano a estreita relação entre vulnerabilidade social e infraestrutural; e as áreas mais suscetíveis a este tipo de fenômeno, situação que caracteriza a segregação urbana. Para tal, faz-se uso de indicadores socioambientais. Com base em dados secundários, obtidos junto ao IBGE e à Prefeitura do Município de São Paulo, desenvolveu-se um conjunto de índices sintéticos. Os mesmos foram integrados e inseridos num Sistema de Informação Geográfica, com vistas a apontar diferentes níveis de vulnerabilidade socioambiental entre os distritos frente ao processo de escorregamento. / With so many crises and disasters in recent years, related to extreme precipitation events, which often result in serious damage and, especially, loss of human lives, the discussion on social and environmental risks gains another dimension. The current model of development is characterized by the risk trivialization, considering that the incessant production of wealth is linked to the production of an increasing number of vulnerable contexts, especially in areas of great poverty - where the response to different impacts is greatly reduced. In the urban environment, the problem is further evidenced by the large extent of areas occupied by slums. The microclimatic changes observed in the large cities, as well as the scenarios presented by the Intergovernmental Panel on Climate Change, indicate the need for developing measures for the proper management of risks related to extreme events, since these may become more frequent and intense in the coming decades. This study seeks to accomplish a multi-dimensional analysis of the vulnerability of São Paulo city against processes related to heavy rainfall, particularly the landslides. Intends to point in space paulistano the close relationship between social and infrastructural vulnerability, and the areas most susceptible to this type of phenomenon, a situation that characterizes urban segregation. To do this, makes use of social and environmental indicators. Based on secondary data, obtained from the IBGE and the Municipality of Sao Paulo, was developed a set of synthetic indices. They were integrated and included in a Geographic Information System, in order to point out different levels of socio-environmental vulnerability among districts facing the process of landslide.

Esta dissertação apresenta o estudo sobre um caso de movimento rotacional em uma massa de solo coluvionar, localizada na Vila Albertina na zona norte da cidade de São Paulo-SP. O objetivo deste trabalho foi estudar os processos de instabilidade associados a eventos de chuvas, condições de fluxo e ações antrópicas que ocorreram no local. Procurou-se estabelecer as relações de causa e efeito que os eventos pluviométricos têm sobre a estabilidade da encosta; também foram estudadas as alterações causadas pelo homem e as condições de infiltração de água no terreno. Foi realizado um levantamento histórico de escorregamentos ocorridos na região desde a década de 30. Este levantamento histórico constituiu em resgatar aerofotografias, imagens de satélites e reconstituições de plantas topográficas do local. Através deste estudo se constatou que a encosta começou a ser modificada desde a década de 40, com uma possível tentativa de exploração de rochas graníticas. Nos anos 60 foi construída uma fábrica no pé da encosta. Atualmente, o solo desta encosta, que está em movimento, invade o pátio desta fábrica. Na década de 70, a área de escorregamento começou a ser ocupada por moradores, que construíram suas casas sobre esta encosta. Esta ocupação foi desordenada e acelerou o processo de instabilização da encosta; até o ano de 2004 viviam no local 600 famílias. No início da década de 80, a encosta apresentou grandes movimentações. Para que estes movimentos fossem cessados, realizaram-se obras de contenção, foram executados retaludamentos, instalações de drenos profundos e drenagens superficiais através de canaletas e escadas hidráulicas. Ainda na década de 80, retirou-se uma grande camada de solo da encosta para cobrir o aterro sanitário da Vila Albertina, localizado no terreno vizinho a encosta. Esta remoção deixou parte do terreno plano, causado o acumulo de águas pluviais. As águas, que antes escoariam superficialmente, passaram a se infiltrar no terreno. Para a caracterização e obtenção dos parâmetros de resistência dos solos da região, foram coletadas três amostras indeformadas: uma na crista do escorregamento e duas no pé da encosta. Neste local, foram identificados um solo coluvionar e um solo residual mais jovem. A encosta foi instrumentada através de marcos superficiais, inclinômetros que também serviram de medidores de nível d\'água e tensiômetros. / This paper presents a study on a rotational movement in a colluvial soil mass located at Vila Albertina, northern region of São Paulo City. The main purpose of this work is to study the processes of instability related to rainfalls, conditions of flow and human actions that occurred at the site. It was intended to establish cause and effect relations pluviometric events have over the stability of the slope. It also studies alterations caused by men and water infiltration conditions on the land. A historical survey of ground sliding data on the region since the 1930s was gathered. This survey was composed of retrieved material such as aerial photographs, satellite images and topographic plans reconstitutions of the location. By means of this study, it was possible to verify that the slope started to be modified since the1940s, with a possible attempt of granite rocks exploitation. In the 60s, a factory was built on the bottom of the slope. Nowadays, the soil of this slope, which is in movement, is invading the courtyard of this factory. In the 70s, the sliding area started to be occupied by inhabitants, who built their homes on this slope. This disorderly occupancy accelerated the instability of the slope; until 2004, 600 families were living in the location. In the beginning of the 80s, the slope presented considerable movements. In order to stop them, contention constructions were executed, as well as re-sloping, installation of deep drains and superficial drainage by channels and hydraulic stairs. Still in the 80s, a great layer of the slopes soil was taken to cover Vila Albertinas sanitary landfill, located at land nearby. This removal left part of the ground plain, causing an accumulation of pluvial water. The pluvial water, which would superficially drain, started to infiltrate into the ground. To characterize and acquire the regions soil resistance parameters, three undisturbed samples were collected: one at the top of the sliding and two at the bottom of the slope. In this area, colluvial and a more recent residual soil were identified. The slope was monitored by superficial indicators, tensiometers and inclinometers that were also used to measure the water level.

Esta dissertação apresenta o estudo sobre um caso de movimento rotacional em uma massa de solo coluvionar, localizada na Vila Albertina na zona norte da cidade de São Paulo-SP. O objetivo deste trabalho foi estudar os processos de instabilidade associados a eventos de chuvas, condições de fluxo e ações antrópicas que ocorreram no local. Procurou-se estabelecer as relações de causa e efeito que os eventos pluviométricos têm sobre a estabilidade da encosta; também foram estudadas as alterações causadas pelo homem e as condições de infiltração de água no terreno. Foi realizado um levantamento histórico de escorregamentos ocorridos na região desde a década de 30. Este levantamento histórico constituiu em resgatar aerofotografias, imagens de satélites e reconstituições de plantas topográficas do local. Através deste estudo se constatou que a encosta começou a ser modificada desde a década de 40, com uma possível tentativa de exploração de rochas graníticas. Nos anos 60 foi construída uma fábrica no pé da encosta. Atualmente, o solo desta encosta, que está em movimento, invade o pátio desta fábrica. Na década de 70, a área de escorregamento começou a ser ocupada por moradores, que construíram suas casas sobre esta encosta. Esta ocupação foi desordenada e acelerou o processo de instabilização da encosta; até o ano de 2004 viviam no local 600 famílias. No início da década de 80, a encosta apresentou grandes movimentações. Para que estes movimentos fossem cessados, realizaram-se obras de contenção, foram executados retaludamentos, instalações de drenos profundos e drenagens superficiais através de canaletas e escadas hidráulicas. Ainda na década de 80, retirou-se uma grande camada de solo da encosta para cobrir o aterro sanitário da Vila Albertina, localizado no terreno vizinho a encosta. Esta remoção deixou parte do terreno plano, causado o acumulo de águas pluviais. As águas, que antes escoariam superficialmente, passaram a se infiltrar no terreno. Para a caracterização e obtenção dos parâmetros de resistência dos solos da região, foram coletadas três amostras indeformadas: uma na crista do escorregamento e duas no pé da encosta. Neste local, foram identificados um solo coluvionar e um solo residual mais jovem. A encosta foi instrumentada através de marcos superficiais, inclinômetros que também serviram de medidores de nível d\'água e tensiômetros. / This paper presents a study on a rotational movement in a colluvial soil mass located at Vila Albertina, northern region of São Paulo City. The main purpose of this work is to study the processes of instability related to rainfalls, conditions of flow and human actions that occurred at the site. It was intended to establish cause and effect relations pluviometric events have over the stability of the slope. It also studies alterations caused by men and water infiltration conditions on the land. A historical survey of ground sliding data on the region since the 1930s was gathered. This survey was composed of retrieved material such as aerial photographs, satellite images and topographic plans reconstitutions of the location. By means of this study, it was possible to verify that the slope started to be modified since the1940s, with a possible attempt of granite rocks exploitation. In the 60s, a factory was built on the bottom of the slope. Nowadays, the soil of this slope, which is in movement, is invading the courtyard of this factory. In the 70s, the sliding area started to be occupied by inhabitants, who built their homes on this slope. This disorderly occupancy accelerated the instability of the slope; until 2004, 600 families were living in the location. In the beginning of the 80s, the slope presented considerable movements. In order to stop them, contention constructions were executed, as well as re-sloping, installation of deep drains and superficial drainage by channels and hydraulic stairs. Still in the 80s, a great layer of the slopes soil was taken to cover Vila Albertinas sanitary landfill, located at land nearby. This removal left part of the ground plain, causing an accumulation of pluvial water. The pluvial water, which would superficially drain, started to infiltrate into the ground. To characterize and acquire the regions soil resistance parameters, three undisturbed samples were collected: one at the top of the sliding and two at the bottom of the slope. In this area, colluvial and a more recent residual soil were identified. The slope was monitored by superficial indicators, tensiometers and inclinometers that were also used to measure the water level.