A statistical comparison between the pre-investigations and the detailed site characterization while tunneling was performed in three areas of different rock quality in the Södermalm’s Tunnel. An overview of the site investigations performed prior to the construction works and the consequences in the tunneling method are also presented in this study. The statistical analyses in this study showed low correlation within the results obtained from the geotechnical investigations performed prior and while tunneling. The correlation diminishes as the rock mass quality decreases; however, in areas where the rock mass quality is high, the correlation is not as elevated as expected. The low association within those results may be due to diverse factors: the concentration of the pre-investigations in mostly three areas along the trace of the tunnel, and the extension of those results to the rest of the tunnel; the inappropriate utilization of the investigation techniques; and the lack of geotechnical data in the regional areas of Stockholm. The inaccurate geological characterization given by the pre-investigations leaded to great challenges in the most fractured and altered areas of the tunnel. A collapse occurred where the glaciofluvial sediments were in contact with the rock. The excavation had to be stopped and additional rock reinforcement had to be applied. Therefore, an increase of the expenses in terms of time and budget were the major consequences of the inaccurate predictions.

O maciço granítico Teles Pires localizado ao norte do estado do Mato Grosso será escavado para a construção de três túneis de desvio utilizados na construção de uma usina hidrelétrica. Para a realização desta escavação, foram realizadas investigações geológicas a fim de se conhecer a condição do substrato rochoso e suas propriedades geomecânicas. Por meio da utilização das classificações geomecânicas RMR e Q, o maciço rochoso foi analisado de modo a se definir as possíveis áreas de instabilidade que poderiam surgir durante as escavações. A utilização de classificações geomecânicas é uma prática difundida na Geologia de Engenharia e utilizada pela maioria das empresas para prever o tipo de tratamento a ser utilizado durante e após a escavação dos túneis. Os métodos abordados neste trabalho levam em consideração parâmetros semelhantes entre si, seguindo cada um uma metodologia distinta. Por considerarem somente alguns parâmetros, as classificações geomecânicas devem ser utilizadas juntamente com as análises de campo e as interpretações geológicas. Neste trabalho, foram analisadas as correlações entre estas duas classificações assim como o quanto elas refletem o contexto geológico ao qual o maciço está inserido. / The Teles Pires granitic massif located north of Mato Grosso State will be excavated for the construction of three detour tunnels used in the construction of a hydroelectric plant. For the realization of this excavation, geological investigations were performed in order to know the condition of the bedrock and its geomechanical properties. Through the use of geomechanical classifications RMR and Q, the rock mass has been analyzed in order to define potential areas of instability that could arise during the excavations. The use of geomechanical classifications are a widespread practice in Engineering Geology and used by most companies to predict the type of treatment to be used during and after excavation of the tunnels. The methods discussed in this paper take into consideration parameters similar to each other, each following a distinct methodology. By considering only a few parameters, geomechanical classifications should be used along with field analysis and geological interpretations. In this study, we analyze the correlations between these two classifications as well as how they reflect the geological context to which the mass is inserted.

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.

O maciço granítico Teles Pires localizado ao norte do estado do Mato Grosso será escavado para a construção de três túneis de desvio utilizados na construção de uma usina hidrelétrica. Para a realização desta escavação, foram realizadas investigações geológicas a fim de se conhecer a condição do substrato rochoso e suas propriedades geomecânicas. Por meio da utilização das classificações geomecânicas RMR e Q, o maciço rochoso foi analisado de modo a se definir as possíveis áreas de instabilidade que poderiam surgir durante as escavações. A utilização de classificações geomecânicas é uma prática difundida na Geologia de Engenharia e utilizada pela maioria das empresas para prever o tipo de tratamento a ser utilizado durante e após a escavação dos túneis. Os métodos abordados neste trabalho levam em consideração parâmetros semelhantes entre si, seguindo cada um uma metodologia distinta. Por considerarem somente alguns parâmetros, as classificações geomecânicas devem ser utilizadas juntamente com as análises de campo e as interpretações geológicas. Neste trabalho, foram analisadas as correlações entre estas duas classificações assim como o quanto elas refletem o contexto geológico ao qual o maciço está inserido. / The Teles Pires granitic massif located north of Mato Grosso State will be excavated for the construction of three detour tunnels used in the construction of a hydroelectric plant. For the realization of this excavation, geological investigations were performed in order to know the condition of the bedrock and its geomechanical properties. Through the use of geomechanical classifications RMR and Q, the rock mass has been analyzed in order to define potential areas of instability that could arise during the excavations. The use of geomechanical classifications are a widespread practice in Engineering Geology and used by most companies to predict the type of treatment to be used during and after excavation of the tunnels. The methods discussed in this paper take into consideration parameters similar to each other, each following a distinct methodology. By considering only a few parameters, geomechanical classifications should be used along with field analysis and geological interpretations. In this study, we analyze the correlations between these two classifications as well as how they reflect the geological context to which the mass is inserted.