Measuring the shore platform width might be an effective way to measure the rate of coastal retreat. The processes controlling shore platforms are a highly debated topic throughout the coastal science community. Some researchers believe that marine processes control them and other researchers believe that physical weathering is responsible. This study determined the relationship between rock mass classification systems and shore platform widths as a diagnostic tool to predict the rate of recession. Testing took place along the Mahia Peninsula and Tatapouri on the East Coast of New Zealand. A Garmin eTrex hand-held GPS unit was used to map both the cliff base position and the edge boundary of the shore platform. Data analysis for Mahia Peninsula showed a linear relationship with a r2 value of 68% with a negative regression line. The data for Tatapouri showed that there was no linear relationship, but has an r2 value of 68% when a polynomial fit to the 2nd order was apply to the data (appendix). The estimated rate of erosion, ranges from 0.61 to 17.8 0.06 mm y-1 for Mahia Peninsula and 1.32 to 16.45 0.08 mm y-1 for Tatapouri.

Characterization of rock masses and evaluation of their mechanical properties are important and challenging tasks in rock mechanics and rock engineering. Since in many cases rock quality designation (RQD) is the only rock mass classification index available, this paper outlines the key aspects on determination of RQD and evaluates the empirical methods based on RQD for determining the deformation modulus and unconfined compressive strength of rock masses. First, various methods for determining RQD are presented and the effects of different factors on determination of RQD are highlighted. Then, the empirical methods based on RQD for determining the deformation modulus and unconfined compressive strength of rock masses are briefly reviewed. Finally, the empirical methods based on RQD are used to determine the deformation modulus and unconfined compressive strength of rock masses at five different sites including 13 cases, and the results are compared with those obtained by other empirical methods based on rock mass classification indices such as rock mass rating (RMR), Q-system (Q) and geological strength index (GSI). It is shown that the empirical methods based on RQD tend to give deformation modulus values close to the lower bound (conservative) and unconfined compressive strength values in the middle of the corresponding values from different empirical methods based on RMR, Q and GSI. The empirical methods based on RQD provide a convenient way for estimating the mechanical properties of rock masses but, whenever possible, they should be used together with other empirical methods based on RMR, Q and GSI. (C) 2016 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Production and hosting by Elsevier B.V.

Empirical design methods are commonly used for rock mechanics evaluations. An appropriate method of rock mass classification is required to use these empirical methods. There are limitations for rock mass classification methods when access to the ore zone is restricted. The Cameco Corporation Eagle Point Mine in northern Saskatchewan, Canada, uses the longhole open stope mining method for the recovery of uranium ore. The Modified Dilution graph is used for the prediction of stope hanging wall dilution. The mine currently uses a rock mass classification based on an estimate of the alteration and strength of a rock mass from geological drift mapping. Since this method is highly subjective, point load testing of diamond drill hole core was completed to attempt to correlate the alteration and strength of different rock types to remove the user subjectivity. The results of the testing indicated a general trend of decreasing rock strength with increasing alteration, albeit with considerable scatter. A repeatable, standardized method of evaluating the stope geometry and inferred rock mass classification for reconciliation purposes was developed. The standardized stope evaluation method removes significant subjectivity currently involved in estimates of stope geometries and the magnitude of dilution. A new lithology based method for interpreting the mine specific geological alteration and strength classification system was developed based on several sources of rock mass classification observations. This resulted in a correlation linking individual rock mass property descriptions between different classification systems for an improved estimate of the Q’ classification value. This improved method of estimating the rock classification Q’ value, as well as conventional techniques for linking classification systems, was used in a stope reconciliation process to predict open stope dilution. Twenty-seven stope reconciliation case histories were documented and used to compare predicted and measured dilution, based on three different approaches for estimating rock mass classification values. The results showed a minor improvement in dilution prediction using the approach developed in this study. The systematic stope reconciliation and rock mass classification approach did highlight areas in the weak pegmatoidal rocks where improved rock classification estimates should be investigated.

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.

Orientador: Persio Leister de Almeida Barros / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-11T23:10:02Z (GMT). No. of bitstreams: 1 D'Alessandro_JulioRomuloPessoa_M.pdf: 4451701 bytes, checksum: d9c3d36b93799d07470f6bbc8779853b (MD5) Previous issue date: 2007 / Resumo: Este trabalho apresenta um estudo de estabilidade através da análise cinemática, para o maciço rochoso da Mineração Casa de Pedra em Congonhas, Minas Gerais, utilizando mapeamento na escala 1:4000. Os parâmetros de resistência e o caimento dos planos das descontinuidades principais foram levantados a partir de um mapeamento geológico geotécnico detalhado. Foram coletados dados nas bancadas de todos os setores da mina a cada quatro metros. Os dados relativos aos pesos da classificação geomecânica de Bieniawski foram compilados em tabelas e posteriormente foram gerados mapas geotécnicos com o auxilio do software ArcView. A classificação geomecânica foi utilizada juntamente com a estimativa da compressão uniaxial de campo para a determinação da resistência do maciço rochoso com o auxilio do software RocLab da Rocscience. Na análise cinemática foram utilizados os ângulos de atrito das litologias predominantes em cada setor, definidas como campos homogêneos e foi realizada uma setorização das cavas em função das descontinuidades principais e da orientação da face do talude em relação a descontinuidade. Com os resultados obtidos pôde-se identificar os setores susceptíveis e aqueles não susceptíveis à ruptura. / Abstract: This work presents the study of the rock mass stability at the Mineração Casa de Pedra , Minas Gerais, using kinematic analisys and maps in 1:4000 scale. The geological structures, the friction angle and cohesion of the rock mass were evaluated through a geological geotecnical mapping technique. Data collected from each bench of the mine were relateded with the rock mass classification RMR and tables were compilled with them. Geotecnical maps were then plotted with the software ArcView. The rock mass classification along with the uniaxial compressive strength estimated in the field were used to determine the shear strength of the rock mass with the software RocLab by Rocscience. The friction angle in each zone, considered as homogeneous field, was used in the kinematic analisys and divisions were done in each mine pit as a function of the major feature and the wall orientation. With the results, the zones could be identified as susceptible or not susceptible to sliding. / Mestrado / Geotecnia / Mestre em Engenharia Civil

The focus on slope stability has increased rapidly in Norway over the last years due to several unwanted landslides. In Norway, the most used method today to classify the rock mass and to determine the required reinforcement, is the Q-system. In addition to that the RMR method is also a commonly used method. However, since both the RMR and the Q-system is created to be used for underground constructions, their slope adaptations (Q-slope and SMR) has been developed. These adaptations will also be evaluated in this thesis. They will be used to examine if there is a correlation between the classification systems and the installed support on site. This thesis will only focus on slopes and not tunnels, as a limit to the scope investigated.  The joints properties at the investigated sites are taken both from engineering geologist reports and field mapping. The mapped joints will be analyzed in Dips to determine the major joint sets and by using the kinematic analysis tool determine what failure mechanisms these joint sets may create. These joint sets will be further evaluated through numerical analysis (with e.g. RocPlane, Swedge or RocTopple) dependent on their failure mechanism. The rock and joint data for calculation is gathered from three different sites, which are all part of the same project where the traffic capacity of the European route E18 through Porsgrunn, outside of Oslo, is increased. In both Blåfjell and Bjønnås the rock mass is larvikite, but in Grenland the rock mass investigated is sandstone. However, the sandstone in the Grenland has undergone contact metamorphosis, which changes the characteristics of the rock mass and creating a much stronger sandstone.  Generally, the rock mass investigated is classified to be of similar quality which gives them the same strength. Consequently, it is difficult to determine any kind of correlation between the sites. The results do not indicate the expected relationship that a stronger rock mass would need less reinforcement. In addition, it is also observed that the classification systems generally recommend more shotcrete that what is installed on site. When comparing the different classification systems, it can be seen that the Q-system generally categorize the rock mass in a lower category, indicating a weaker rock mass, compared to RMR and SMR. This then results in that the rock masses investigated is classified to be ranging from Poor to Good, dependent on the classification method.   Keywords: Rock mass classification, Q-slope, SMR, Slope stability.

The three most common rock mass classification systems in use in the South African mining industry today are Bieniawski’s (1976) Geomechanics or RMR System, Barton et al.’s (1974) Q-System and Laubscher’s (1990) MRMR System respectively. Of these three systems, only the MRMR Classification System was developed specifically for mining applications, namely caving operations. In response to the increased use of the MRMR Classification System in the mining industry, and concerns that the MRMR System does not adequately address the role played by discontinuities, veins and cemented joints in a jointed rock mass, Laubscher and Jakubec introduced the In-Situ Rock Mass Rating System (IRMR) in the year 2000. A quantitative comparison of the MRMR and IRMR Classification Systems has been undertaken to determine a correlation between the two classification systems, the results of which indicate that there is not a major difference between the resultant rock mass rating values derived from the two Classification Systems. Therefore, although the IRMR System is more applicable to a jointed rock mass than the MRMR System, the MRMR System should not be regarded as redundant, as it still has a role to play as a mine design tool.

A implantação segura e a viabilidade de um projeto de barragem dependem de se conhecer, com o máximo de clareza, as características geotécnicas do substrato rochoso do local de implantação. Para tanto, são realizadas campanhas de investigação geotécnica para a elaboração de modelos geológicos e geomecânicos, os quais podem apresentar erros devido à variabilidade natural, amostragem insuficiente, interpretação bidimensional e subjetividade das interpretações. Visando diminuir a subjetividade das interpretações acerca das características geomecânicas, a mecânica das rochas utiliza classificações de maciço rochoso, tais como sistema Q, de Barton, e RMR, de Bieniawski. Surgida por volta de 1960, a geoestatística permite analisar fenômenos que não são totalmente aleatórios e cujos valores dependem de sua posição no espaço. Este trabalho consistiu em desenvolver modelos numéricos tridimensionais a partir da aplicação da classificação de maciço rochoso pelo sistema RMR (Rock Mass Rating), utilizando técnicas geoestatísticas para a interpolação em regiões não amostradas. Os objetivos foram identificar feições e zonas com características geotécnicas de menor qualidade, verificar a representatividade dos modelos numéricos frente as estruturas geológicas mapeadas, observar a influência de fatores de redução nas classificações de RMR e analisar a variação de resultados quando são usadas malhas de amostragem diferentes. Os resultados obtidos foram satisfatórios, tanto do ponto de vista geoestatístico quanto do ponto de vista geotécnico. Foram delimitadas as regiões de atenção e identificadas as principais estruturas e feições geológicas nos modelos de RMR. Foi possível avaliar a influência dos fatores de redução na classificação de maciço, assim como a influência da malha de amostragem nos resultados estatísticos, geoestatísticos e de interpolação. Os dados amostrais foram comparados entre si e evidenciaram a importância e superioridade da classificação por RMR em detectar as principais feições e características geológicas, assim como demonstraram a variação da sensibilidade quando se utiliza diferentes fatores de redução. / A safe dam installation and its project feasibility, necessarily, depends on knowing, to the clearest, the geotechnical rock substrate characteristics in the installation place. Therefore, geotechnical investigation campaigns are undertaken to elaborate geological and geomechanics models, which may present errors due to natural variability, insufficient sampling, two-dimensional interpretation and subjectivityes. Aiming to decrease the subjectivism in the interpretations regarding the geomechanics characteristics, the rock mechanics makes use of rock mass classifications such as Q, by Barton, and RMR, by Bieniawski. Developed about 1960, geostatistics allows to analyze phenomena not completely random and whose values depend on its special position. This study consisted in developing three-dimensional numerical models from the rock mass assessment with RMR, using geostatistics to interpolate data in regions without sampling. The objectives were to identify features and zones with poor geotechnical characteristics, to evaluate how representative the numerical models are compared to the mapped geological structures, to observe the influence of reduction factors in the RMR classification and to analyze the variation of the results when different sampling grids are used. The obtained results were satisfactory, both in the geostatistical and geotechnical aspects. The critical regions were delimitated and the main geological structures and features were identified in the RMR model. It was possible to evaluate the influence of the reduction factors in the rock mass assessment, as well as the influence caused by the sampling grids in the statistic, geostatistics and interpolated results. Sampled data were compared and demonstrated how important and how superior the RMR assessment is to detect the major features and geological characteristics, as well as to demonstrate how sensitive the variation of the results is when different reduction factors are used.

Os sistemas de classificação maciços rochosos e as redes neurais artificiais possuem diversas similaridades. Existem características que estão presentes nos dois tipos de sistemas: bases de dados são usadas para o seu desenvolvimento; e pesos são parte da representação do conhecimento. Os principais sistemas de classificação geomecânicas (Sistema Q e RMR) podem ser escritos como representações neurais locais. Tais representações permitem uma melhor compreensão do processo de classificação e identificação de padrões realizado pelas classificações convencionais. Experimentos convencionais foram realizados com modelos de redes neurais não-supervisionados. Os modelos não supervisionados permitiriam uma melhor compreensão da distribuição dos dados no espaço de feições. Um modelo supervisionado para escavações subterrâneas em todo domínio do espaço de feições. Importantes relações entre características foram encontradas. / Rock mass classification systems and artificial neural networks have several similarities. There is some characteristics present in both systems: data bases are used in they development, and weights are part of the knowledge representation. The main rock mass classification systems (Q-system and RMR) can be written as local neural network representations. This representation helps a better understanding of the pattern classification and identification process made by the conventional classifications. Computational experiments were made with unsupervised and supervised neural networks models. Unsupervised models allow a better understanding of the data in the feature space. A supervised model allow to make a mapping of the support type used in underground excavation in all feature space domain. Important relations between domain regions characteristics and type of support used were found.

A implantação segura e a viabilidade de um projeto de barragem dependem de se conhecer, com o máximo de clareza, as características geotécnicas do substrato rochoso do local de implantação. Para tanto, são realizadas campanhas de investigação geotécnica para a elaboração de modelos geológicos e geomecânicos, os quais podem apresentar erros devido à variabilidade natural, amostragem insuficiente, interpretação bidimensional e subjetividade das interpretações. Visando diminuir a subjetividade das interpretações acerca das características geomecânicas, a mecânica das rochas utiliza classificações de maciço rochoso, tais como sistema Q, de Barton, e RMR, de Bieniawski. Surgida por volta de 1960, a geoestatística permite analisar fenômenos que não são totalmente aleatórios e cujos valores dependem de sua posição no espaço. Este trabalho consistiu em desenvolver modelos numéricos tridimensionais a partir da aplicação da classificação de maciço rochoso pelo sistema RMR (Rock Mass Rating), utilizando técnicas geoestatísticas para a interpolação em regiões não amostradas. Os objetivos foram identificar feições e zonas com características geotécnicas de menor qualidade, verificar a representatividade dos modelos numéricos frente as estruturas geológicas mapeadas, observar a influência de fatores de redução nas classificações de RMR e analisar a variação de resultados quando são usadas malhas de amostragem diferentes. Os resultados obtidos foram satisfatórios, tanto do ponto de vista geoestatístico quanto do ponto de vista geotécnico. Foram delimitadas as regiões de atenção e identificadas as principais estruturas e feições geológicas nos modelos de RMR. Foi possível avaliar a influência dos fatores de redução na classificação de maciço, assim como a influência da malha de amostragem nos resultados estatísticos, geoestatísticos e de interpolação. Os dados amostrais foram comparados entre si e evidenciaram a importância e superioridade da classificação por RMR em detectar as principais feições e características geológicas, assim como demonstraram a variação da sensibilidade quando se utiliza diferentes fatores de redução. / A safe dam installation and its project feasibility, necessarily, depends on knowing, to the clearest, the geotechnical rock substrate characteristics in the installation place. Therefore, geotechnical investigation campaigns are undertaken to elaborate geological and geomechanics models, which may present errors due to natural variability, insufficient sampling, two-dimensional interpretation and subjectivityes. Aiming to decrease the subjectivism in the interpretations regarding the geomechanics characteristics, the rock mechanics makes use of rock mass classifications such as Q, by Barton, and RMR, by Bieniawski. Developed about 1960, geostatistics allows to analyze phenomena not completely random and whose values depend on its special position. This study consisted in developing three-dimensional numerical models from the rock mass assessment with RMR, using geostatistics to interpolate data in regions without sampling. The objectives were to identify features and zones with poor geotechnical characteristics, to evaluate how representative the numerical models are compared to the mapped geological structures, to observe the influence of reduction factors in the RMR classification and to analyze the variation of the results when different sampling grids are used. The obtained results were satisfactory, both in the geostatistical and geotechnical aspects. The critical regions were delimitated and the main geological structures and features were identified in the RMR model. It was possible to evaluate the influence of the reduction factors in the rock mass assessment, as well as the influence caused by the sampling grids in the statistic, geostatistics and interpolated results. Sampled data were compared and demonstrated how important and how superior the RMR assessment is to detect the major features and geological characteristics, as well as to demonstrate how sensitive the variation of the results is when different reduction factors are used.