Σκοπός της παρούσας Διατριβής Ειδίκευσης είναι η παρακολούθηση του κατολισθητικού φαινομένου του οικισμού Καρυάς του Δήμου Πατρέων, με μετρήσεις αποκλισιομέτρων ώστε να προσδιοριστεί ποσοτικά ο ρυθμός μετακίνησης της περιοχής μελέτης και να εξαχθούν συμπεράσματα για την μελλοντική του εξέλιξη, όπως καθορίζεται μέσω αναλύσεων ευστάθειας πρανών. Η εν λόγω περιοχή παρουσιάζει αξιόλογο ενδιαφέρον, λόγω των ιδιαίτερων και σύνθετων γεωλογικών συνθηκών, των συχνών και σημαντικών κατολισθητικών φαινομένων των τελευταίων ετών που προκάλεσαν σημαντικές καταστροφές σε τεχνικά έργα και ανθρώπινες περιουσίες. Στα πλαίσια της Διατριβής και της παράλληλης Έρευνας του Εργαστηρίου Τεχνικής Γεωλογίας στην περιοχή ενδιαφέροντος πραγματοποιήθηκε λεπτομερής γεωτεχνική έρευνα που περιελάμβανε ανόρυξη δειγματοληπτικών γεωτρήσεων σε επιλεγμένες θέσεις με ταυτόχρονη τοποθέτηση αποκλισιομέτρων, συστηματική λήψη αποκλισιομετρικών μετρήσεων, σειρά εργαστηριακών και επί τόπου δοκιμών σε κατάλληλα διαμορφωμένα δείγματα, λεπτομερή καταγραφή των τεχνικογεωλογικών συνθηκών της περιοχής με βάση κυρίως τη σύσταση, τη δομή των γεωλογικών σχηματισμών. Έγινε διάκριση των σχηματισμών της περιοχής έρευνας σε επιμέρους Γεωτεχνικές Ενότητες και σχεδιάστηκαν αντιπροσωπευτικές γεωτεχνικές – τεχνικογεωλογικές διατομές με σκοπό τη σύνθεση και ερμηνεία του γεωτεχνικού περιβάλλοντος της περιοχής. Παράλληλα πραγματοποιήθηκαν αναλύσεις ευστάθειας πρανών με χρήση εξειδικευμένου λογισμικού σε επιλεγμένες διατομές κατά μήκος των γεωτρήσεων στην κατολισθαίνουσα ζώνη Καρυάς. Σκοπός των αναλύσεων ευστάθειας πρανών ήταν να γίνει εκτίμηση πιθανών μετακινήσεων σε επιλεγμένα σημεία της περιοχής έρευνας και να παρατηρηθεί εάν το είδος ολίσθησης εξακολουθεί να είναι το ίδιο με αυτό που είχε διαπιστωθεί κατά την τελευταία εκδήλωση του κατολισθητικού φαινομένου. / The Aim of this ΜSc. Project is the exploration of the landslide phenomeno in the region of Karya, Patras, Western Greece by inclinometer measurements in order to define quantitatively the movement rate of the study area and export conclusions on its future development, as it specified via slope stability analysis. The study area is an area with complex geological conditions and is well known especially for the important and large-scale landslide phenomena which have taken place during the last years near Karya village and caused important destructions in engineering works and human fortunes. This project was done along with survey of the Laboratory of Engineering Geology, Geology Department, University of Patras. The full survey program included geological mapping focused on the engineering properties of the soil and rock formations, fifteen (15) sampling boreholes, inclinometer installation and measurement and laboratory tests. Through laboratory testing and detailed description of soil and rock samples the formations were classified in several units and several geotechnical cross-sections were constructed to make a general geological-geotechnical model of the study area. The geological and geotechnical data were used to perform Limit Equilibrium Slope Stability analysis. The survey results were used to define probable movements of the study area and to establish the slipping type.

The City of Winnipeg, located at the confluence of the Red and Assiniboine Rivers, has over 240 km of natural riverbank property. The increased frequency and magnitude of flooding along the Red and Assiniboine Rivers over the past decade appears to have influenced the number of slope failures along riverbank property, resulting in the loss of both public green space and privately owned land. The loss of private and public property adjacent to the river has led to the loss of valuable real estate and public parkland amenities. To ensure that riverbank property is preserved for future generations, the City of Winnipeg wants to increase the stability of certain reaches of publicly owned riverbank property along the Red and Assiniboine Rivers that are prone to slope movements. Extensive research has been conducted on slope stability problems in the Winnipeg area, but a transparent prioritization procedure for the remediation of riverbank stability problems has not existed. Therefore, a Riverbank Asset Management System (RAMS) was developed for publicly owned riverbank property to prioritize riverbank slope stability problems along the Red and Assiniboine Rivers. The RAMS provides the City of Winnipeg with a rational approach for determining risk levels for specific reaches of the Red and Assiniboine Rivers. The calculated risk levels allow the City to develop recommended response levels for slope stability remediation projects in a fiscally responsible manner with minimal personal and political influences. This system permits the City to facilitate timely and periodic reviews of priority sites as riverbank conditions and input parameters change.

Geotechnical engineering design has relied upon deterministic methods of analysis whereby values for analysis parameters and conditions are selected subjectively based on judgment with the intent of providing acceptable margins of safety. The objective of this research was to improve the use of probabilistic slope stability analysis in practice so that the design of slopes can be made on a consistent and probabilistic basis. The current research involved the development of a methodology for the measurement and modeling of the anisotropic autocorrelation distance of cohesive soils, which was demonstrated at Dyke 17 West of the McArthur Falls Generating Station. In-situ testing using the piezocone and laboratory testing was conducted to characterize the spatial variability of the effective-shear strength envelope. Vertical (down-hole) and horizontal (cross-hole) geostatistical analysis was conducted to assess the anisotropy of the semivariogram. The investigation identified that heterogeneous inclusions had significant impacts on the results, but that simplistic (visual) identification and filtering procedures were adequate. The effective-stress shear strength envelope was statistically characterized as a random field, which was simulated as a first-order Markov process using customized add-in functions in a limit-equilibrium slope stability analysis. The analysis accounts for the spatial variability of shear strength and is capable of simulating both isotropic and anisotropic autocorrelation functions. The study showed that the critical slip surface geometry and the probability of failure can be significantly different when the anisotropy of spatial correlation is accounted for. The study also showed that neglecting spatial correlation may over-estimate the probability of failure, however this finding was noted to be likely case-specific. The primary conclusion of the study was that appropriate representation of spatial correlation is essential to calculating the probability of failure. Finally, convergence of the probabilistic simulation was evaluated using bootstrapping of the simulated factor of safety distribution to assess the standard error in the mean factor of safety, standard deviation of factor of safety and the probability of failure. A convergence criterion based on the percentage standard error in the probability of failure was proposed and used to define the number of Monte-Carlo iterations required.

Element test results reported in the literature under both triaxial and plane strain conditions indicate that loose saturated granular specimens can experience softening instability at stress ratios lower than what might otherwise be expected given the critical state friction angle of the soil. The region of potential softening instability in stress-space is often explained using the framework of the instability line. This phenomenon is particularly relevant to shallow slopes of 1 to 2 m depth. However, the practical realities of sample preparation for triaxial testing make performing tests below 20 to 30 kPa of confining stress exceptionally difficult. In this thesis, the development of a centrifuge tilt-table test device is described which aims to test the behaviour of loose granular slopes under stress paths of increasing slope inclination or increasing pore water pressure. A system of instrumentation including pore pressure transducers, inclinometers, displacement transducers, and high-resolution cameras was designed to monitor the behaviour of the slope model. The development of a system to provide a controlled groundwater level within the slope model proved to be particularly challenging. The results of two competing design concepts are presented for the water boundary condition and discussed. The centrifuge tilt-table is used to compare the physical response of a slope to the behaviour predicted by the infinite slope and softening instability models using scale model centrifuge testing. If softening instability is a rigorous concept, it should be the primary observed failure mechanism as it will occur at a stress state below the failure line. Tests were performed on loose Ottawa F110 sand at 1g, 20g and 40g and 60g. Deviatoric strain-softening was observed in loose dry sand. The softening instability event resulted in a rapid increase in shear strain at constant shear stress while the soil was at a stress state below the failure envelope. Any soil that can experience softening instability (i.e. granular, loose, saturated, and behaves undrained) will undergo two failures: one caused by deviatoric strain-softening (softening instability) and a second caused by shear failure at a larger slope angle. / Thesis (Master, Civil Engineering) -- Queen's University, 2014-04-29 22:01:36.786

The City of Winnipeg, located at the confluence of the Red and Assiniboine Rivers, has over 240 km of natural riverbank property. The increased frequency and magnitude of flooding along the Red and Assiniboine Rivers over the past decade appears to have influenced the number of slope failures along riverbank property, resulting in the loss of both public green space and privately owned land. The loss of private and public property adjacent to the river has led to the loss of valuable real estate and public parkland amenities. To ensure that riverbank property is preserved for future generations, the City of Winnipeg wants to increase the stability of certain reaches of publicly owned riverbank property along the Red and Assiniboine Rivers that are prone to slope movements. Extensive research has been conducted on slope stability problems in the Winnipeg area, but a transparent prioritization procedure for the remediation of riverbank stability problems has not existed. Therefore, a Riverbank Asset Management System (RAMS) was developed for publicly owned riverbank property to prioritize riverbank slope stability problems along the Red and Assiniboine Rivers. The RAMS provides the City of Winnipeg with a rational approach for determining risk levels for specific reaches of the Red and Assiniboine Rivers. The calculated risk levels allow the City to develop recommended response levels for slope stability remediation projects in a fiscally responsible manner with minimal personal and political influences. This system permits the City to facilitate timely and periodic reviews of priority sites as riverbank conditions and input parameters change.

Σκοπός είναι η αποτύπωση της κατάστασης κατολισθαίνουσας ζώνης στον οικισμό Μαζαράκι Ηλείας, η οποία ενεργοποιήθηκε στον οδικό άξονα Μαζαράκι-Πρόδρομος μετά τις πυρκαγιές του 2007 που έπληξαν τον Νομό Ηλείας. Περιλαμβάνει αποτύπωση και χαρτογράφηση της κατολισθαίνουσας ζώνης, αποτελέσματα τεχνικογεωλογικής - γεωτεχνικής μελέτης που πραγματοποιήθηκαν στον χώρο και αποτελέσματα ευστάθειας πρανών. / The purpose of this essay is to imprint the behaviour of sliding-zone, in the region of Mazaraki, Ilia, which was activated on Mazaraki- Prodromos road after the fire that stroke Ilia area in 2007. The essay includes, survey and maps of the sliding-zone, results of technogeological – geotechnical survey that was carried out in the area, as well as results of slope stability.

Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第14136号 / 工博第2970号 / 新制||工||1441(附属図書館) / 26442 / UT51-2008-N453 / 京都大学大学院工学研究科社会基盤工学専攻 / (主査)教授 中川 一, 教授 関口 秀雄, 教授 藤田 正治 / 学位規則第4条第1項該当

Esta dissertação discute o emprego de técnicas de estabilização de taludes rodoviários de corte e aterros utilizando drenagem superficial e vegetação. Os conceitos de aplicação de vegetação no aumento da resistência do solo, diminuição da poro-pressão e diminuição da erosão superficial do terreno são revisados. O trabalho discute a importância da interação solo-vegetação, sua influência em taludes, a importância da matéria orgânica nos solos, a sucessão vegetal com vegetação nativa. Estes conceitos foram utilizados na análise de um trecho da BR386, entre a entrada para a via de acesso a Progresso até Canoas, atualmente em processo de duplicação. A partir da inspeção de campo foram identificados os principais problemas de instabilidade e erosão da obra. Foram coletadas seis amostras de solos de quatro taludes da obra para caracterização e para melhor descrição dos problemas de ruptura superficial e controle de erosão nos cortes e aterros analisados. Os materiais amostrados envolveram duas amostras com característica de argila de alta plasticidade, uma argila de baixa plasticidade, uma areia siltosa não plástica, uma areia argilosa e uma areia argilosa não plástica. Foram analisados os problemas encontrados em campo, em função do tipo de materiais, tendo sido propostas soluções adaptadas a cada caso, principalmente focando problemas referentes à drenagem e a busca de soluções ambientais eficazes e com preservação do caráter paisagístico. / This work discusses the use of stabilization techniques for road cuttings and embankments using drainage and vegetation. The concepts of increase soil strength due to vegetation, decrease of the pore pressure and reduction in erosion of the ground surface are reviewed. The work also discusses the importance of soil-vegetation interactions, their influence on slopes, the importance of organic matter in soils and plant succession with native vegetation. These concepts were used in the analysis of a length of the BR386 highway, between the entrance to the access route to Progress up to Canoas, currently in the process of duplication. From the field inspection the main problems of instability and erosion of the works were identified. Six soil samples were collected from four slopes for soil characterization and better description of the superficial instabilities and erosion control in the cuts and embankments analyzed. The materials involved two samples with characteristic of high plasticity clay, low plasticity clay, non plastic silty sand and sand clay not plastic. The problems encountered in the field were analyzed, considering the type of soils involved and proposals of solutions have been made adapted for each case, mainly focusing on drainage and the search for effective environmental solutions which preserve the landscape character.

A presente dissertação apresenta um estudo experimental e de simulação de fluxo de água investigando os efeitos de chuvas torrenciais sobre o solo existente em um talude da região de São Vendelino. Para este estudo foi selecionada uma encosta na qual houve duas ocorrências de rupturas rasas que deram origem a corridas de detritos num evento importante que ocorreu no local em dezembro de 2000. Ao longo da cicatriz deixada por uma delas, foram realizados ensaios de caracterização e determinadas as propriedades hidráulicas do solo a partir de ensaios de campo e de laboratório. Os ensaios de campo compreenderam ensaios com o permeâmetro de Guelph, ensaios com piezômetros de tubo aberto e infiltrômetro de anel duplo. Em laboratório foram realizados ensaios utilizando dois diferentes permeâmetros de parede flexível. Foi feita também a determinação da curva característica do solo através do método do papel-filtro. A partir das propriedades hidráulicas do solo, da geometria do talude e espessura dos materiais, obtidas a partir de topografia, foram realizadas análises de fluxo utilizando o programa Seep/W simulando a precipitação medida de 148 mm/2 h que deflagrou as corridas de detritos de dezembro de 2000. As análises mostraram que, como o solo coluvionar tem uma condutividade hidráulica bastante elevada, ocorre a infiltração de toda a chuva ocorrida. As análises de fluxo mostraram uma elevação progressiva do nível freático com o tempo, o qual atinge a superfície do terreno no trecho crítico do talude (trecho de maior inclinação) após cerca de 95 minutos de precipitação. Análises de estabilidade simplificadas (talude infinito) mostram fatores de segurança próximos da unidade com o nível freático em 80% da camada de solo coluvionar, considerando o trecho mais íngreme do talude. Embora com algumas simplificações de análise, estes resultados mostram que as análises de fluxo e de ruptura, utilizando dados reais medidos em campo, são muito promissores pois conseguem modelar de forma adequada a ruptura ocorrida (FS=1,0). / This dissertation presents an experimental study and a simulation of hydraulic flow in a slope at São Vendelino region, to investigate the effects of torrential rains on the existing soil. A natural slope was selected in which two shallow slope failures had occurred in December 2000 during a serious debris flow event. Soil characterization tests and hydraulic properties have been determined in the laboratory on soil samples taken close to one of the scars left by the failures. The field tests involved Guelph permeameter, stand pipe piezometers and doublering infiltrometer tests. Tests on two different flexible wall permeameter tests and the determination of the moisture-suction characteristic curve have also been carried out in the laboratory. Using the measured soil hydraulic properties, the slope geometry and soil covering depths obtained through topography, some hydraulic flow analyses have been carried out. The SEEP/W software was used and the measured precipitation of 148mm/ 2h, which caused the debris flow event of December 2000, was simulated. The analyses have shown that all the precipitation can infiltrate, as the soil has a large hydraulic conductivity, and there is a progressive rising of the phreatic line with time. This level of water reaches the soil surface in the critical length of the slope (the length with the larger inclination) after 95 min of rain. Simplified slope stability analysis (infinite slopes) had shown values of safety factors close to one in the critical length of the slope when the phreatic line is at 80% depth of the colluvium soil. Although there are some simplifications in the analysis, these results show that the flow and the stability analyses using the real data collected from field tests modeled in an appropriate way the real failure (FS~1,0).

O crescimento econômico acarreta na necessidade de aumento de capacidade de rodovias existentes. Quando localizadas em meia-encostas, muitas vezes estão vinculadas a ocorrências de instabilidade de modo que obras de aumento da capacidade geram grande impacto. O objetivo desta pesquisa é avaliar o aumento de capacidade de um trecho da Rodovia ERS/122, minimizando os impactos através da definição da seção-tipo com dimensões mínimas, segurança para o usuário, e utilização de um material leve como aterro a ser construído na meia encosta. O principal material avaliado para utilização como aterro são restos de pneus triturados, já encontrados no mercado atual. A avaliação desta solução de aterro em meia encosta decorre principalmente do fato de evitar desmontes de rocha que ocasionariam a interrupção do tráfego em uma importante rodovia do estado. Aliado a isso, é baixa a ocorrência de solos de boa qualidade no trecho, de modo que o aterro é geralmente realizado com materiais rochosos de ocorrência local ou materiais importados. A possibilidade de diminuir a utilização de um material nobre a ser explorado na natureza, juntamente com a utilização de materiais que ainda não possuem 100% de destinação adequada, aliada ao baixo peso específico e adequada resistência ao cisalhamento, incentivaram a realização dos estudos. Ensaios de resistência ao cisalhamento e comportamento de compressão foram realizados para avaliar os parâmetros geotécnicos, a fim de obter um modelo geomecânico. Devido aos resultados de teste satisfatórios, tem sido considerado possível o uso de tais materiais. Os parâmetros obtidos em condições de confinamento foram aceitáveis para aterros de rodovias especialmente quando as aparas de pneus foram misturadas com agregados rochosos. Seu uso como um material de aterro pode ser incentivado, a fim de reduzir o uso de rochas naturais, para obter uma utilização adequada de restos de pneus e para gerar uma maior estabilidade dos aterros com a substituição de solos com comportamento geotécnico pobre. Isto é conseguido principalmente pela diminuição do peso do aterro, pela melhoraria das condições de drenagem e pela definição de uma seção transversal geometricamente segura. / Economic growth leads to the need to increase the capacity of existing highways. When crossing natural slopes often are linked to occurrences of instability so that increased work capacity generate big impact. The objective of this research is to evaluate the increase in capacity of a highway stretch ERS / 122, minimizing impacts by setting the standard section with minimum dimensions, but safe for the user, using a lightweight material as fill. The main material evaluated for use as embankment is shredded tire debris, already found on the market. The evaluation of this embankment solution on natural slopes is mainly to avoid rock blasting which would interrupt the traffic on this important State highway. As there is few occurrences of good quality soil near the construction sites, the fills are usually built with local or imported rock materials. The ability to reduce the use of rock to be exploited from nature by the use of recycled materials combined with its low specific weight and adequate shear strength encouraged this study. Tests of shear strength and compression behavior were carried out to evaluate geotechnical parameters in order to obtain a geomechanical model. Due to satisfactory test results the use of such materials has been considered possible. The parameters obtained on confined conditions were acceptable for road fills especially when scrab tires were mixed with rock aggregates. Its use as an embankment material can be incentivatedf in order to reduce the use natural rocks, to obtain an adequate use for tire scraps and to generate a greater stability for embankments as replacement of soils with poor geotechnical behavior. This is achieved mainly by decreasing landfill weight, improving the drainage conditions and definition of geometrically safe embankment cross-section.