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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Maciços rochosos em projetos hidrelétricos : proposta de classificação geomecânica /

Mesquita, João Batista de. January 2008 (has links)
Resumo: Desenvolveu-se proposta de classificação geomecânica de maciços rochosos para uso em projetos e obras de hidrelétricas a céu aberto, tendo como base estrutural o sistema Rock Mass Ration (RMR), proposto por Bieniawski (1989), para aplicação nas fases de: viabilidade e projeto básico, e projeto executivo (obras civis), direcionado, sobretudo para as atividades de preparo, tratamento e liberação das fundações. Os parâmetros classificatórios, simples e consagrados no meio técnico, são obtidos por meio de procedimentos metodológicos e pesquisa comumente empregados, tendo como estudo de casos os Aproveitamentos Hidrelétricos Jirau e Serra do Facão, localizados no rio Madeira, município de Porto Velho- RO e rio São Marcos em Catalão-Go, Brasil. O sistema básico foi testado e avaliado nos dois projetos hidrelétricos citados e ainda foram demonstradas incoerências do sistema RMR, na obtenção e aplicação dos pesos relativos dos parâmetros fraturamento e Rock Quality Designation (RQD), tendo sido solucionadas na presente tese. Introduziu-se de forma inédita como parâmetro de ajuste com pesos positivos, os tratamentos de fundação aplicados, que deverá ser objeto de calibração em projetos e obra em curso, que poderá servir para avaliar o coeficiente de segurança de determinada estrutura, por meio do ganho que é submetido o maciço rochoso tratado dos índices e parâmetros geotécnicos Os parâmetros e pesos da classificação da fase de projeto são revistos e ou determinados para a classificação fase de obras, durante o preparo e liberação da fundação, e nessa oportunidade pode-se reavaliar as especificações técnicas e aplicabilidade do projeto executivo, nessa área específica. Demonstrou-se a metodologia de obtenção de parâmetros geomecânicos, testou-se e avaliouse nos casos citados a Proposta Classificação Geomecânica e, finalmente... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: There has been developed geomechanic classification of rock mass for outdoors use in projects and works of hydroelectrics, having as structural basis the Rock Mass Ration (RMR) System, proposed by Bieniawski (1989), for application in the phases of viabilitiy and basic project, and executive project (civil works) mainly directed for the activities of preparation, treatment and liberation of the foundations. The classificatory parameters, simple and consecrated in technical environment, are obtained from methodological procedures and researches, having as cases of study Jirau and Serra do Facão Hydroelectric Uses located in the Madeira River, in the region of the city of Porto Velho-RO and in São Marcos River, in Catalão-GO, Brazil. The basic system was tested and appraised in the two mentioned hydroelectric projects and incoherences of the system were still demonstrated RMR, in the obtaining and application of the relative weights of the parameters Fracturement and Rock Quality Designation (RQD), having been solved in the present thesis. It was introduced in an unpublished way as adjustment parameter with positive weights, the applied foundation treatments, that should be calibration object in projects and work in course, that it can be to evaluate safety's certain structure coefficient, through the earnings that is submitted the rocky solid agreement of the indexes and parameters geotecnics. The parameters and weights of the classification of the project phase are reviewed and or certain for the classification phase of works, during the preparation and liberation of the foundation, and in that opportunity it can be revalued the technical specifications and aplicabilidade of the executive project, in that specific area. The methodology of obtaining of parameters geomechanics was demonstrated, it was tested and it was evaluated in the mentioned cases the developed geomechanic... (Complete abstract click electronic access below) / Orientador: José Alexandre de Jesus Perionotto / Coorientador: André Pacheco de Assis / Banca: Adalberto Aurélio Azevedo / Banca: Fábio Soares Guimarães / Banca: Leandro Eugênio da Silva Cerri / Banca: Vanderlei Maniesi / Doutor
2

Stability Investigations Along The Ordu Peripheral Highway

Sopaci, Evrim 01 December 2003 (has links) (PDF)
The Eastern Black Sea region of Turkey accomodates indecent residence conditions for people owing to ground conditions comprising of volcanics and concurrent flysch, and its related irregular geomorphology. One of the important difficulties in this region is transportation. Accordingly, the ordu peripheral highway which encompasses various structures such as, open cuts, bridges, viaducts and junctions and double tubed tunnel sections which will be driven in these geological and geomorphological conditions is palnned to be constructed. In regional scale, volcanics, pyroclastics and flysch deposits often intertounge with each other even over very short distances. The accurate determination of the shear strength parameters of these lithologies is vital for the assessment of portal slope stability and support design in regards to tunnel design. Rock mass classification systems, namley, RMR, NGI Q system and GSI, have been employed to obtain the rock mass shear strength parameters. Stress analyses around the tunnel opennings have been executed through employing 2D finite element analysis in an attempt to design tunnel support. The results of the analysis have been correlated with the results obtained from the emprical methods. The overall analyses and interpretations led to the determination of the support systems to be employed during tunnel construction.
3

Maciços rochosos em projetos hidrelétricos: proposta de classificação geomecânica

Mesquita, João Batista de [UNESP] 17 November 2008 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:32:18Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-11-17Bitstream added on 2014-06-13T18:43:33Z : No. of bitstreams: 1 mesquita_jb_dr_rcla.pdf: 5875287 bytes, checksum: db2a8395dcb44ca32fbf3d80e933e123 (MD5) / Desenvolveu–se proposta de classificação geomecânica de maciços rochosos para uso em projetos e obras de hidrelétricas a céu aberto, tendo como base estrutural o sistema Rock Mass Ration (RMR), proposto por Bieniawski (1989), para aplicação nas fases de: viabilidade e projeto básico, e projeto executivo (obras civis), direcionado, sobretudo para as atividades de preparo, tratamento e liberação das fundações. Os parâmetros classificatórios, simples e consagrados no meio técnico, são obtidos por meio de procedimentos metodológicos e pesquisa comumente empregados, tendo como estudo de casos os Aproveitamentos Hidrelétricos Jirau e Serra do Facão, localizados no rio Madeira, município de Porto Velho- RO e rio São Marcos em Catalão-Go, Brasil. O sistema básico foi testado e avaliado nos dois projetos hidrelétricos citados e ainda foram demonstradas incoerências do sistema RMR, na obtenção e aplicação dos pesos relativos dos parâmetros fraturamento e Rock Quality Designation (RQD), tendo sido solucionadas na presente tese. Introduziu-se de forma inédita como parâmetro de ajuste com pesos positivos, os tratamentos de fundação aplicados, que deverá ser objeto de calibração em projetos e obra em curso, que poderá servir para avaliar o coeficiente de segurança de determinada estrutura, por meio do ganho que é submetido o maciço rochoso tratado dos índices e parâmetros geotécnicos Os parâmetros e pesos da classificação da fase de projeto são revistos e ou determinados para a classificação fase de obras, durante o preparo e liberação da fundação, e nessa oportunidade pode-se reavaliar as especificações técnicas e aplicabilidade do projeto executivo, nessa área específica. Demonstrou-se a metodologia de obtenção de parâmetros geomecânicos, testou-se e avaliouse nos casos citados a Proposta Classificação Geomecânica e, finalmente... / There has been developed geomechanic classification of rock mass for outdoors use in projects and works of hydroelectrics, having as structural basis the Rock Mass Ration (RMR) System, proposed by Bieniawski (1989), for application in the phases of viabilitiy and basic project, and executive project (civil works) mainly directed for the activities of preparation, treatment and liberation of the foundations. The classificatory parameters, simple and consecrated in technical environment, are obtained from methodological procedures and researches, having as cases of study Jirau and Serra do Facão Hydroelectric Uses located in the Madeira River, in the region of the city of Porto Velho-RO and in São Marcos River, in Catalão-GO, Brazil. The basic system was tested and appraised in the two mentioned hydroelectric projects and incoherences of the system were still demonstrated RMR, in the obtaining and application of the relative weights of the parameters Fracturement and Rock Quality Designation (RQD), having been solved in the present thesis. It was introduced in an unpublished way as adjustment parameter with positive weights, the applied foundation treatments, that should be calibration object in projects and work in course, that it can be to evaluate safety's certain structure coefficient, through the earnings that is submitted the rocky solid agreement of the indexes and parameters geotecnics. The parameters and weights of the classification of the project phase are reviewed and or certain for the classification phase of works, during the preparation and liberation of the foundation, and in that opportunity it can be revalued the technical specifications and aplicabilidade of the executive project, in that specific area. The methodology of obtaining of parameters geomechanics was demonstrated, it was tested and it was evaluated in the mentioned cases the developed geomechanic... (Complete abstract click electronic access below)
4

Distinct element modelling of jointed rock masses : algorithms and their verification

Boon, Chia Weng January 2013 (has links)
The distinct element method (DEM) is a useful tool in rock engineering to model jointed rock masses. To simulate a jointed rock mass realistically, the main challenge is to be able to capture its complex geometry which consists of blocks with various shapes and sizes, and to model the interactions between these blocks. The main contribution of this thesis is the development of novel algorithms in the DEM to model jointed rock masses, namely rock slicing procedures for block generation, and algorithms for contact detection between polygonal blocks in 2-D or polyhedral blocks in 3-D. These algorithms make use of convex optimisation techniques, for which there exist efficient solution procedures. They do not rely on conventional vertex-edge-face hierarchical data structures and tedious housekeeping algorithms. The algorithms have been verified against analytical and numerical solutions, as well as validated against experimental results published in the literature. Among those, the results of DEM simulations were compared against the experimental model tests and numerical simulations of jointed beams carried out by Talesnick et al. (2007) and Tsesarsky & Talesnick (2007) respectively. Emphasis was placed on modelling the stiffness of the block interfaces accurately, and this was accomplished by reinterpreting the laboratory data published by the investigators. The capabilities of the numerical tools are also examined and demonstrated in areas for which the DEM has found practical application. A substantial fraction of this thesis is devoted to illustrating how these tools can assist the engineer in designing support systems; for example, designing the length and spacing of rock bolts and the lining thickness for a tunnel. Algorithms to model rock bolt and lining support were implemented for this purpose. Interesting comparisons with elastic solutions for supported openings were obtained. Further, it is shown that the relative benefit of introducing more rock bolts or thicker lining can be evaluated using the numerical tools with the aid of an interaction diagram. In the final part of this thesis, the case history of the 1963 Vaiont rock slide in Italy is studied. The 2-D analyses led to useful insights concerning the influence of the reservoir water level, the rock mass strength and deformability, and the slide surface shear stiffness. 3-D analyses were undertaken to investigate the influence of the eastern boundary of the slope, and interesting insights were obtained concerning the slope kinematics. Overall, the case study shows that the tools are capable of modelling problems with specific physical and geometrical detail in both 2-D and 3-D.

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