Assessing Rock Mass Permeability Using Discontinuity Properties

Field measurement of rock mass permeability is essential that numerous factors influence its directional magnitude. Lugeon test is a popularly conducted field instrument in order to measure hydraulic conductivity of a rock mass. Discontinuity orientation, spacing and discontinuity surface quality, infill presence and type play essential role in permeability of the rock mass in addition to rock material itself. Geological Strength Index (GSI) is a parameter used in Gen. Hoek-Brown failure criterion and supporting empirical equations in order to estimate rock mass strength and deformability parameters. Frequently used Rock Quality Designation (RQD) and GSI and Lugeon values were combined in order to generate a relation among them. The proposed relationships are produced by interpretation of geotechnical core logging and Lugeon test results.