The New Ulus Tunnel will be constructed within the andesitic terrain at Hidirliktepe (Ankara). Excavation of the tunnel will be accomplished through blast and drill method. Emprical methods will be consulted during the design of the support systems as well as the slope of the portal rock face. Therefore it is essential to perform detailed rock mass characterization studies. In this thesis it is aimed to determine the rock mass characteristics in order to design the rock slope of the portals and to assess the reliable support systems for the tunnel. For this purpose laboratory tests and field investigations were conducted. Field investigations involved detailed discontinuity measurements and borehole drillings. In respect of laboratory tests / point load index, unit weight and uniaxial compression strength tests were used. The field and laboratory test results were utilized in the Rock Mass Classification Systems (RMR, Q-system) in order to ascertain the rock mass characteristics. By all accounts, necessary tunnel support systems were determined. As for the portal areas, the rock face design was accomplished through kinematical analyses. Consequently, no failure is expected at the portal rock slopes.

Com a abertura do setor de geração de energia elétrica no país houve um aumento do número de projetos para pequenas centrais hidrelétricas - PCHs. Os estudos geológico-geotécnicos necessários para este tipo de obra tiveram que se adaptar às necessidades deste novo setor, sem haver perda da qualidade. O objetivo deste trabalho foi o aprimoramento dos estudos de compartimentação geológico-geotécnicos, utilizando um dos sistemas de classificação de maciços rochosos mais conhecidos: o Sistema RMR - rock mass rating - (Bieniawski, 1973), analisando as vantagens, as desvantagens, e o potencial de aplicação do método. A pesquisa foi aplicada na PCH Morro Grande, localizada no Rio Grande do Sul, que apresenta uma grande homogeneidade geológica, sendo o embasamento constituído por derrames basálticos da Formação Serra Geral. Foram propostas algumas modificações na forma de aplicação do sistema RMR, como não pré-compartimentar o maciço, aplicar a classificação diretamente nos testemunhos de sondagem e de forma parcial nos afloramentos, e substituir o RQD (rock quality designation) pelo IQR (índice de qualidade da rocha). Para caracterizar a resistência da rocha foram feitos ensaios de compressão puntual, associados aos diferentes graus de alteração da rocha. O resultado foi apresentado em seções do eixo da barragem e do circuito hidráulico. A metodologia proposta resultou na compartimentação detalhada do maciço rochoso, na área das estruturas da PCH, mostrando-se uma ferramenta útil para a determinação da compartimentação de maciços rochosos, principalmente de maciços homogêneos, podendo ser aplicadas de forma rápida e a um custo baixo para o projeto. / The opening of the electric production sector in Brazil causes an increase amount of Small Hydroelectric Power Station - PCH\'s - project. The necessaries geological-geotechnical studies for this kind of construction had to be adapted to this new sector necessity, without quality losses. This research aim was the improvement of the geological-geotechnical studies, using one of the most well-known rock mass classification systems: the RMR system - rock mass rating - (Bieniawski, 1973), and analyze the advantage, the disadvantage, and potential of this method application. This research was applied to Morro Grande PCH, located on Rio Grande do Sul state - Brazil, which has great geologic homogeneity, and its rock foundation is basaltic rocks of the Serra Geral Formation. Some modification in the RMR application way has been proposal, like don\'t pre-divide the rock mass, apply the system directly in the core logging and partially to the outcrops, and change RQD (rock quality designation) by IQR (rock quality index). To rock strength have been established by point-load test, for the different weathering degrees of the rock samples. The results are presented on profiles of the structures axis. The propose method resulted in detailed compartimentalization of the structures areas, turning into an useful tool to assist the rock mass analyses, mainly to homogeneous rock masses, been applied quickly and at low costs.

Com a abertura do setor de geração de energia elétrica no país houve um aumento do número de projetos para pequenas centrais hidrelétricas - PCHs. Os estudos geológico-geotécnicos necessários para este tipo de obra tiveram que se adaptar às necessidades deste novo setor, sem haver perda da qualidade. O objetivo deste trabalho foi o aprimoramento dos estudos de compartimentação geológico-geotécnicos, utilizando um dos sistemas de classificação de maciços rochosos mais conhecidos: o Sistema RMR - rock mass rating - (Bieniawski, 1973), analisando as vantagens, as desvantagens, e o potencial de aplicação do método. A pesquisa foi aplicada na PCH Morro Grande, localizada no Rio Grande do Sul, que apresenta uma grande homogeneidade geológica, sendo o embasamento constituído por derrames basálticos da Formação Serra Geral. Foram propostas algumas modificações na forma de aplicação do sistema RMR, como não pré-compartimentar o maciço, aplicar a classificação diretamente nos testemunhos de sondagem e de forma parcial nos afloramentos, e substituir o RQD (rock quality designation) pelo IQR (índice de qualidade da rocha). Para caracterizar a resistência da rocha foram feitos ensaios de compressão puntual, associados aos diferentes graus de alteração da rocha. O resultado foi apresentado em seções do eixo da barragem e do circuito hidráulico. A metodologia proposta resultou na compartimentação detalhada do maciço rochoso, na área das estruturas da PCH, mostrando-se uma ferramenta útil para a determinação da compartimentação de maciços rochosos, principalmente de maciços homogêneos, podendo ser aplicadas de forma rápida e a um custo baixo para o projeto. / The opening of the electric production sector in Brazil causes an increase amount of Small Hydroelectric Power Station - PCH\'s - project. The necessaries geological-geotechnical studies for this kind of construction had to be adapted to this new sector necessity, without quality losses. This research aim was the improvement of the geological-geotechnical studies, using one of the most well-known rock mass classification systems: the RMR system - rock mass rating - (Bieniawski, 1973), and analyze the advantage, the disadvantage, and potential of this method application. This research was applied to Morro Grande PCH, located on Rio Grande do Sul state - Brazil, which has great geologic homogeneity, and its rock foundation is basaltic rocks of the Serra Geral Formation. Some modification in the RMR application way has been proposal, like don\'t pre-divide the rock mass, apply the system directly in the core logging and partially to the outcrops, and change RQD (rock quality designation) by IQR (rock quality index). To rock strength have been established by point-load test, for the different weathering degrees of the rock samples. The results are presented on profiles of the structures axis. The propose method resulted in detailed compartimentalization of the structures areas, turning into an useful tool to assist the rock mass analyses, mainly to homogeneous rock masses, been applied quickly and at low costs.

Manual fracture mapping in tunnels, caverns, mines or other underground spaces is a time intensive and sometimes dangerous process. A system that can automate this task could minimize human exposure to rockfalls, rockbursts or instabilities and facilitate the use of new methods of data visualization such as virtual environments. This research was undertaken to develop VTtrace; a semi-automatic fracture mapping algorithm based on image processing and analysis techniques. Images of a rock exposure surface are made using a "prosumer" grade digital camera. The grayscale images are preprocessed to remove color information and any noise or distortion. The smoothed images are converted into binary images. The binary images are then thinned to extract the fracture map. The fractures are then separated and stored as different images. Fracture properties such as the length, width, orientation and large-scale roughness are determined using photogrammetric techniques. Results from test images shows the VTtrace is effective in extracting rock discontinuity traces. Additional enhancements to the program are proposed to allow feature attributes from the three-dimensional surface to be determined. / Master of Science

Construction of rock slopes is needed in many civil work projects. It is for example very common in road and railway cuts, but other applications include excavation for tunneling or building foundations, where perhaps sensitive constructions are present in the immediate vicinity. In Sweden the majority of the rock is hard crystalline bedrock of relatively good quality, and the fracture orientation have a large effect of the stability of the rock slope.If the geology is not properly considered for when the design of the slope is carried out, it can result in slope failure, with severe consequences. This applies especially if the rock slope is high, but unwanted effects like increased excavation and construction costs, could occur also in smaller slopes if the risks are not identified and managed. However, it is difficult to standardize design of rock slopes in fractured hard crystalline rock because of the uncertainties and variations in the geological conditions during the design phase.Rock mass characterization systems like Rock mass rating, RMR (Bieniawski 1989) and the Qsystem (Barton, Lien och Lunde 1974) are commonly used to describe the general rock mass quality. Whilst a good rock mass quality is generally easier to construct in, stability problems do occur due to structural geology in rock slopes even in good rock mass quality. The application of these systems in rock slopes can be problematic as they do not describe the geometry of the slope and how the fractures daylight in the slope face. Instead, stereonets can be used to visualize this, but fracture parameters of large importance for stability (persistence, roughness and alteration) are traditionally not presented in a stereonet analysis. Additionally, these parameters and the structural geological conditions can be difficult to predict and can vary significantly over short distances, why it can be difficult to forecast and predict failure in the design face.Slope instability due to large sliding and wedge failures have been observed in a large number of slopes in crystalline rock, and a standard method for design of rock slopes is lacking. This has given rise to the research question of how best to describe rock mass conditions, how to design slopes in crystalline rock and how to manage these risks during construction.To investigate this, three rock slopes where large failure had occurred were selected for the case study and were mapped, characterized and analyzed. The results from the case study showed that all rock slopes investigated had in common that failure had occurred along fractures of large persistence. This highlights the importance of evaluating the geology in the correct scale and suggest that lineament studies and other elevation based interpretation are perhaps more useful than previously thought. It also came to light that the planning and design process is inflexible which in many cases lead to large risks being overlooked or left unnoticed.A flow chart for risk classification was produced and suggested for aid in decision making aiming at simplifying project management of rock slopes, as well as aiding in visualization of the risk that rock slopes can be associated to.

The sublevel caving mining method is a mass production method with potentially very low operational costs. The success of this method is dependent on, among other factors, the cavability of the orebody and the overlying rock mass. However, caving of the surrounding rock mass also results in deformations in the cap rock as well as on the ground surface above the orebody being mined. From this follows that any existing infrastructure on the ground surface must be relocated as not to be affected by the mining-induced deformations.This thesis work was undertaken to bring about a better understanding of the rock mass behavior in the cap rock of non-daylighting orebodies, with particular application to the Printzsköld orebody as part of the LKAB Malmberget Mine. Rock testing, field observations and underground mapping was conducted to characterize the rock mass in the caving environment. A methodology for identifying the caving front based on seismic monitoring data was derived by studying the Fabian orebody (which has caved to surface), and using laser scanning data for validation. The methodology was then applied to the Printzsköld orebody to identify the caving front.Numerical modeling was performed for various scenarios of the rock mass as mining proceeded. Modeling included (i) stress analysis to understand stress changes and their effects on the rock mass behavior, (ii) discontinuum numerical modeling to quantify the influence of large-scale geological structures on the cave progression, and (iii) discontinuum cave modeling to simulate possible cave mechanisms in the cap rock more explicitly. Laser scanning together with seismic event data were used to calibrate the numerical models.The numerical simulation results showed that as mining progresses, the cap rock and hangingwall were exposed to stress changes that resulted in yielding. Two failure mechanisms were predominantly at play (i) shear failure (dominant in the cap rock) and (ii) tensile failure (dominant in the hangingwall). The presence of the large-scale structures affected thenearfield stresses through slip along the cave boundaries. The effect of the structures on the far field stresses were less significant.Discontinuum modeling to explicitly simulate failure and caving involved simulating the rock mass as a jointed medium using Voronoi tessellations in 2D, and bonded block modeling (BBM) in 3D. Both the 2D and the 3D modeling results showed fair agreement when comparing the inferred boundary of the seismogenic zone, with that identified from seismic monitoring data. Predictive numerical modeling was conducted for future planned mining to assess future cave development in the cap rock. The results from 3D modeling indicated that cave breakthrough for the Printzsköld orebody is expected when mining the 1023 m level, corresponding to approximately year 2022, as per current mining plans. The 2D model was non-conservative with cave breakthrough predicted to occur when mining the 1109 m level, corresponding to the year 2028.The estimated boundary between the seismogenic and yielded zones, as defined in the Duplancic and Brady conceptual model of caving, was coinciding with, or was close to, the cave boundary in the Printzsköld orebody. This may imply that in some areas the yielded zone was not present and that the Duplancic and Brady model may not be universally applicable. Additional work is required to verify this indication, as well as to fine-tune the modeling methodology.