La construction d’un ouvrage hydraulique commence par le choix des matériaux devant le constituer. Les sols employés pour la construction d’ouvrages hydrauliques en terre peuvent être constitués de matériaux perméables tels que les sables ou les graves ou de matériaux peu perméables tels que les argiles ou les limons. En fonction de la disponibilité des matériaux à proximité du chantier, il est alors possible d’opter pour différents types d’ouvrages (ouvrages homogènes, à noyau ou zonés). Dans tous les cas, le coût d’un ouvrage tel qu’une digue est d’autant moins élevé que les sols utilisés pour sa construction sont issus de zones proches du chantier. Lorsque des sols sont disponibles en quantité suffisante à proximité du chantier mais que leur utilisation soit risquée pour la stabilité de l’ouvrage, il peut être opportun de chercher à modifier leurs caractéristiques pour qu’ils puissent être utilisés dans les mêmes conditions de sécurité que les matériaux traditionnels. C’est autour de cette problématique que ce travail de thèse a vu le jour. En particulier, ce travail vise à étudier les améliorations apportées par un traitement à la chaux appliqué sur un sol grossier soumis à un écoulement interne afin de le stabiliser contre le phénomène de l’érosion interne. La compréhension des améliorations apportées a nécessité la mise en place d’une analyse multicritère au travers d’essais dédiées. Dans la première partie de la thèse, nous nous sommes employés à développer un dispositif d’essais permettant de réaliser des essais d’érosion interne sur ce type de sol. Ce dispositif nous a permis de réaliser une étude phénoménologique sur le comportement du sol considéré, soumis à des écoulements, en fonction du sens de l’écoulement et de l’application ou pas du traitement. Par la suite une étude paramétrique a été réalisée afin de mettre en évidence l’influence des paramètres principaux : dosage de traitement, temps de cure, hauteur de l’éprouvette et surcharge. Dans une seconde partie, nous nous sommes intéressés à l’influence de l’immersion des échantillons dans l’eau sur leur stabilité. A cet effet, l’essai de dispersion, adapté à ce type de sol, a pu être utilisé et exploité. Des essais complémentaires de résistance à la compression simple ont été réalisés afin d’estimer la perte de résistance après immersion. Ce qui nous a poussés à examiner l’existence de corrélations entre les propriétés à l’érosion et les propriétés mécaniques du sol traité / The construction of a hydraulic structure starts with the selection of the materials that will constitute it. The soils used in the construction of hydraulic earthen structures may be made of permeable materials such as sands or low permeability materials such as clay or silt. Depending on the availability of materials near the site, it is possible to choose different types of structures (homogeneous structures, core or zoned). In all cases, the cost of such a structure as a dike is even lower than the soils used for its construction come from areas near the site. When soils are sufficiently available near the construction site, but their use is risky for the stability of the structure, it may be appropriate to seek to modify their characteristics so they can be used in the same security conditions than traditional materials. It is around this issue that this thesis was born. More particularly, this research aims to study the improvements made by a lime treatment on a coarse soil subjected to internal flow to stabilize against the phenomenon of internal erosion. Understanding improvements requires the establishment of a multi-criteria analysis through dedicated tests. In the first part, we are interested in developing a testing device for performing internal erosion tests on this type of soil. This device has enabled us to realize a phenomenological study of the phenomena observed with the direction of flow and the presence or not of the treatment. Subsequently a parametric study was conducted to highlight the influence of the main parameters: treatment dosage, treatment time, height of the specimen and overload. In the second part, we studied the influence of immersion samples in water for this purpose the crumb test test was adapted for this type of soil. Additional unconfined compression tests were conducted to estimate the loss of strength after immersion. This allowed us to try couplings between the properties to erosion and soil treated mechanical properties

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第20324号 / 工博第4261号 / 新制||工||1660(附属図書館) / 京都大学大学院工学研究科社会基盤工学専攻 / (主査)教授 木村 亮, 教授 三村 衛, 准教授 木元 小百合 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

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京都大学 / 新制・課程博士 / 博士(工学) / 甲第23489号 / 工博第4901号 / 新制||工||1766(附属図書館) / 京都大学大学院工学研究科都市社会工学専攻 / (主査)教授 岸田 潔, 教授 木村 亮, 准教授 音田 慎一郎 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

Master of Science / Department of Computing and Information Sciences / Mitchell L. Neilsen / In recent years, headline news has been overwhelmed with stories about dam and levee failures including the 2005 levee breaches in New Orleans and the 2006 Kaloko Damfailure in Hawaii that resulted in seven deaths. Since 2000, state and federal agencies have reported 92 dam failures in the United States to the National Performance of Dams Program. Incidents such as these have brought both national and worldwide attention to the need for improved flood warning systems and breach prediction tools for dam embankment and levee failures. (G. J. Hanson, 2010) IESIMBA 2012 is an upgraded version of SIMBA, which has been upgraded from VB6 to C#.NET. The Microsoft Windows-based SIMplified Breach Analysis software (SIMBA) was developed by the USDA Agricultural Research Service in cooperation with Kansas State University. The software was developed for the purpose of analyzing internal erosion, earth embankment breach test data and extending the understanding of the underlying physical processes of breach of an overtopped earth embankment. It is a research tool that is modified routinely to test the sensitivity of the output to various sub-models and assumptions. This software is a test version for use in validation testing of the simplified breach model based on stress and mass failure driven headcut movement. It runs under Microsoft Windows 98SE, Windows 2000, NT, XP, or Vista. The following Input Screens are used to guide the user through development of input data sets.  Model Properties , Dam Profile , Structure Table, Spillway Rating and Hydrograph Data After an input data set has been entered, the data is saved and simulation can be performed on the data stored in memory at any time by selecting Build option. Input and output files are stored in a fixed ASCII text format. The results of the simulation can be viewed in graphical format which are of interest to the researchers at Oklahoma State University, Stillwater by selecting View option.

Ce travail de thèse porte sur l'étude des mécanismes de blocage d'un écoulement d'eau dans un milieu granulaire par injection d'un produit de colmatage, et s'inscrit plus généralement dans la problématique de l'érosion interne des sols (Projet National ERINOH). Cette recherche, à dominante expérimentale, s'appuie sur une modélisation physique unidimensionnelle. Pour cela, une conduite d'écoulement de 18 cm de diamètre intérieur et 300 cm de longueur maximale, constituée par plusieurs tronçons de 50 cm de longueur assemblés, a été développée. Celle-ci est tout d'abord remplie du matériau granulaire perméable à étudier ; on établit ensuite un écoulement d'eau permanent à pression imposée à l'amont ; finalement on vient injecter localement un produit de colmatage pour essayer de bloquer l'écoulement. Le dispositif est équipé de plusieurs capteurs de pression, de débitmètres, d'un turbidimètre afin de mettre en évidence les paramètres significatifs qui contrôlent le processus de blocage. Les paramètres expérimentaux sont les caractéristiques du milieu granulaire (type de sol, conductivité hydraulique, état de compacité…), les caractéristiques de l'écoulement (vitesses, gradients hydrauliques, régime de l'écoulement…), les propriétés rhéologiques du coulis d'injection (densité, viscosité, seuil de cisaillement…) et la technique d'injection associée. Sur la base des résultats obtenus, on propose des critères de blocage de l'écoulement combinant ces derniers paramètres sous une forme suffisamment simple, utilisable dans la pratique, pour répondre à la demande des industriels impliqués dans le projet de recherche ERINOH, qui sont confrontés à ces pathologies / The present PhD thesis focuses on the mechanisms of blocking permanent water flow through a granular soil by injection of a grout. This work is part of the more general problem of internal erosion of soils (French National Project ERINOH). This research, mainly experimental, is based on a one-dimensional physical modelling. For this, a new original prototype setup, allowing to generate permanent flow in a 18 cm inner diameter and 3 m long plexiglas pipe, has been developed. It is first filled with a highly permeable granular medium, then permanent flow of water is generated at controlled upstream pressure, and finally the grout is injected locally in order to try to block the water flow. The set-up is equipped with multiple pressure sensors, flowmeters, a turbidimeter to monitor the significant parameters that control the clogging process. The experimental parameters are the characteristics of the granular medium (soil type, hydraulic conductivity, density ...), the flow characteristics (flow rate, hydraulic gradient, flow regime ...), the rheological properties of the grout (density, viscosity, yield stress ...) and the associated injection technique. Based on the results obtained, clogging criteria are proposed, as a function of the parameters involved, in a simple form for use in practice.Key-words: internal erosion, clogging, injection, grout, bentonite, yield stress, viscosity.

Submitted by Pedro Lemos Camarero null (camarero@folha.com.br) on 2016-05-23T22:57:01Z No. of bitstreams: 1 Análise de integridade Física de Barragens de Terra a partir da integração do método geofísico da eletrorresistividade com ensaios geotécnicos.pdf: 5497568 bytes, checksum: 87ea6f438628a89617555e0a6fb716dc (MD5) / Rejected by Ana Paula Grisoto (grisotoana@reitoria.unesp.br), reason: Solicitamos que realize uma nova submissão seguindo a orientação abaixo: O arquivo submetido não contém a Folha de aprovação. A versão submetida por você é considerada a versão final da dissertação/tese, portanto não poderá ocorrer qualquer alteração em seu conteúdo após a aprovação. Corrija esta informação e realize uma nova submissão contendo o arquivo correto. Agradecemos a compreensão. on 2016-05-25T19:40:42Z (GMT) / Submitted by Pedro Lemos Camarero null (camarero@folha.com.br) on 2016-05-26T17:51:45Z No. of bitstreams: 1 Análise de integridade Física de Barragens de Terra a partir da integração do método geofísico da eletrorresistividade com ensaios geotécnicos.pdf: 5603284 bytes, checksum: 57cc0506d6e9e96bea9a3ed5dc59a2e7 (MD5) / Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-05-30T17:17:09Z (GMT) No. of bitstreams: 1 camarero_pl_me_rcla.pdf: 5603284 bytes, checksum: 57cc0506d6e9e96bea9a3ed5dc59a2e7 (MD5) / Made available in DSpace on 2016-05-30T17:17:09Z (GMT). No. of bitstreams: 1 camarero_pl_me_rcla.pdf: 5603284 bytes, checksum: 57cc0506d6e9e96bea9a3ed5dc59a2e7 (MD5) Previous issue date: 2016-04-15 / Dams are structures that dam rivers and streams for a variety of purposes. These structures, often need to be sturdy to withstand the force of the impoundment and the high values of accumulated water load. The constant maintenance of these structures is essential, since a possible accident can lead to damage of catastrophic proportions. This study presents an inexpensive alternative, simple and quick application for investigation of seepage of water in Earth dams, built with distinct loan material. The research methods used were: geotechnical tests as granulometric analysis, determination of the physical indexes of soil, permeability test with permeameter of Guelph and the geophysical method of electric resistivity, from electrical resistivity tomography. At each dam, were acquired three geophysical lines parallel to the longitudinal axis of the dam. The spacing between electrodes was 2m and the array used in the study was Wenner. The results are presented from geophysical images with 2D and 3D electrical resistivity values measured and modeled, where it was possible to identify areas of low relative values of electrical resistivity, interpreted as saturated areas and likely infiltration of the body of the dam. The quantitative data of the Geotechnical testing contribute to greater understanding of the internal water flow. / Barragens são estruturas que represam rios e córregos para diversas finalidades. Essas estruturas, geralmente precisam ser robustas para suportar a força do represamento e os altos valores de carga de água acumulados. A constante manutenção dessas estruturas é imprescindível, uma vez que um acidente eventual pode gerar danos de proporções catastróficas. Esse estudo apresenta uma alternativa barata, de simples e rápida aplicação para investigação de zonas de percolação de água em barragens de terra, construídas com material de empréstimo distintos. Os métodos de investigação utilizados foram: ensaios geotécnicos como análise granulométrica, determinação dos índices físicos do solo, ensaio de permeabilidade com o permeâmetro de Guelph e, o método geofísico da eletrorresistivade, a partir da técnica do imageamento elétrico. Em cada barragem, foram adquiridas três linhas geofísicas paralelas ao eixo longitudinal da barragem. O espaçamento entre eletrodos foi de 2m e o arranjo utilizado no estudo foi o Wenner. Os resultados são apresentados a partir de imagens geofísicas 2D e 3D com valores de resistividade elétrica medida e modelada, onde foi possível identificar zonas de baixos valores relativos de resistividade elétrica, interpretadas como zonas saturadas e de provável infiltração no corpo da barragem. Os dados quantitativos dos ensaios geotécnicos contribuem para maior entendimento do fluxo hídrico interno.

The Lossen dam is an embankment dam in the Swedish river Ljusnan. The dam is founded on thick layers of stratified glaciofluvial sediments and till. Ever since construction, there have been problems with high pore pressures, large seepage flows and springs downstream of the right part of the dam. After the first filling of the reservoir, a large drainage trench was constructed downstream of the dam to lower pore pressures. Sinkholes and settlements downstream of the dam have occurred repeatedly over the lifetime of the dam, particularly in the area surrounding the large drainage trench. This study aims to investigate the causes of the sinkholes and assess the risks of internal erosion in the foundation and in the soil downstream of the dam. A model of the groundwater flow has been created in Visual MODFLOW. Calculations for assessing the soils susceptibility for contact erosion and suffusion have been performed, using soil gradation curves (both from the 1960s and from new samples). The results from the erosion calculations show that the probability of contact erosion being the sole cause of the internal erosion is minor. However, a majority of the soil samples tested are internally unstable (susceptible for suffusion). The possibility of backward erosion piping can not be dismissed but would need further investigation in order to be properly assessed. Due to the very heterogeneous structure of the soil in the area downstream of the dam, it is hard to predict the extent of the eroding soil layers and, thus, the future development of the erosion. A conclusion is that the soil downstream of the dam is subject to internal erosion, which is also the cause of the observed sinkholes and settlements. The internal erosion is probably not a threat to dam safety at the moment, but can possibly evolve as a problem in the future. Therefore close monitoring of the changes in seepage patterns and sediment transport is recommended. Possible solutions to stop the erosion include extending the drainage system with more pressure relief wells, and placing a filter blanket in the seepage exit area. / Lossendammen är en jorddamm i älven Ljusnan.  Dammen är byggd ovanpå tjocka lager av morän och isälvssediment. Sedan första dämningen 1962 har problem med höga portryck, stora läckageflöden och källsprång nedströms dammen uppkommit. Efter första dämningen grävdes ett stort dränagedike (kallat Slits 19) ut nedströms om dammen, för att sänka portrycken i området. Sjunkhål och sättningar har uppkommit återkommande under dammens livstid, speciellt i området kring slitsen. Målet med denna studie är att undersöka orsaken till de uppkomna sjunkhålen och sättningarna, samt att bedöma risken för fortsatt intern erosion i dammens undergrund och i jorden nedströms dammen. En modell över grundvattenflödet i området har skapats i Visual MODFLOW. Jordens fallenhet för kontakterosion och suffusion har beräknats med hjälp av kornfördelningskurvor från jordprover (majoriteten av vilka är från 60-talet, samt några nya). Resultaten från beräkningarna visar att risken för att kontakterosion initieras är liten. Däremot visar en majoritet av de testade kornfördelningskurvorna att jorden är internt instabil (har fallenhet för suffusion). Sannolikheten för att bakåtskridande erosion initieras kan inte uteslutas baserat på det underlag som förelegat, men en pålitlig bedömning skulle kräva ytterligare undersökningar. Eftersom jorden under och nedströms dammen är väldigt heterogen, och de olika lagrens storlek och utbredning är okänd, är det svårt att förutspå hur erosionen kommer att utvecklas i framtiden. Slutsatsen är att jorden nedströms dammen utsätts för fortlöpande inre erosion. Inre erosion är också orsaken till de uppkomna sjunkhålen och sättningarna. I nuläget är erosionen ingen risk för dammsäkerheten, men kan komma att bli det i framtiden. Noggrann övervakning av eventuella förändringar i läckagemönstren och sedimenttransport är viktig. Bland möjliga lösningar för att avstanna erosionen finns utökning av dränagesystemet med nya filterbrunnar, samt att lägga ett filtrerande skyddslager över området där källsprången sker.

Seepage-related erosion is one of the predominant mechanisms responsible for incidents and failures of dams and levees. Current geotechnical engineering practice consists of comparing expected exit gradients with the critical gradient of the soil at the seepage exit point. The critical gradient is generally considered as the ratio of soil buoyant unit weight and the unit weight of water, suggesting that the critical gradient only depends on the void ratio and specific gravity of the solids. However, in the field and in research, it has been observed that piping can initiate at average gradients much lower than unity due to concentrations in flow and non-vertical exit faces. Therefore, there is a need for deeper understanding of the granular scale mechanisms of the piping erosion process. This thesis presents the results of a laboratory study to assess the effects that soil properties and exit face configurations have on the potential for initiation of piping and the piping mechanisms. By using a laboratory device designed and constructed specifically for this study, the critical gradients needed to initiate piping in a variety of sandy soils were measured to assess the effects that parameters such as gradation, grain size, and grain shape have on the critical gradients. The tests are also used to observe the grain scale mechanisms of piping erosion initiation. The ultimate goal of the study is to develop an empirical, but mechanism-based, grain-scale model that can take into account the effects of converging flows, non-horizontal exit faces, and soil properties while assessing the potential for piping erosion to occur.

<p>Dams that comprise broadly and widely graded glacial materials, such as moraines, have been found to be susceptible to internal erosion, perhaps more than dams of other soil types. Internal erosion washes out fine-grained particles from the filling material; the erosion occurs within the material itself or at an interface to another dam zone, depending on the mode of initiation. Whether or not internal erosion proceeds depend on the adequacy of the filter material. If internal erosion is allowed, it may manifest itself as sinkholes on the crest, increased leakage and muddy seepage once it surfaces, which here is called surfacing internal erosion (i.e. internal erosion in the excessive erosion or continuation phase). In spite of significant developments since the 1980s in the field of internal erosion assessment, the validity of methods developed by others on broadly graded materials are still less clear because most available criteria are based on tests of narrowly graded granular soils. This thesis specifically addresses dams that are composed of broadly graded glacial soils and investigates typical indicators, signs and behaviors of internal erosion prone dams. Based on a review of 90+ existing moraine core dams, which are located mainly in Scandinavia as well as North America and Australia/New Zealand, this thesis will show that not only the filter’s coarseness needs to be reviewed when assessing the potential for internal erosion to surface (i.e., erosion in the excessive or continuing phase); in addition, the grading stability of the filter and the core material as well as non-homogeneities that are caused by filter segregation need to be studied. Cross-referencing between these aspects improves the assessment of potential for internal erosion in dams of broadly graded soils and furthermore it provides aid-to-judgment.</p> / QC 20100715