Rock mass characterization along the tunnel axis for Golen Gol hydropower project Chitral,Pakistan

The characterization of rock mass is an essential part of the preliminary engineering design in the field of civil and mining engineering. it is considered very beneficial when limited geological and geotechnical data of site is available. in the present research,the empirical methods i.e. rock mass rating (rmr),tunneling quality index (q-system) and geological strength index (gsi) classification systems for assessment and classification of rock mass along the axis of tunnel. these empirical methods were applied on the geological and geotechnical data collected along the axis of tunnel. the strength properties and intrinsic properties of rock samples,which are important for characterization,were determined in the laboratory. the rock mass along tunnel axis was characterized based on the empirical methods,intrinsic and strength properties of the rock mass. after characterization,the rock mass was divided into three geotechnical units i.e. gu-1,gu-2 and gu-3. different support systems for each geotechnical unit were recommended to stabilize the tunnel. the conventional drilling and blasting technique was proposed for driving of the tunnel. © 2016,national centre of excellence in geology. all rights reserved.