Hydraulic three-dimensional tests - Comparison of concepts and results with single packer tests

Special three dimensional (3-D) hydraulic tests can be used to determine the hydraulic directional properties of anisotropic jointed rock masses in foundations and abutments of dams, mines, tunnels, caverns and other engineering subterraneous work. These tests are an advanced version of single hole packer tests often performed to characterise the permeability of fractured rock masses. This paper discusses the importance of these special hydraulic three dimensional (borehole-to borehole) tests to characterise the anisotropic directional permeability of the jointed medium, and demonstrates some of the advantages of these tests. In view of the strong anisotropy of most fractured rock masses, three dimensional tests provide much better and precise information about the directional hydraulic properties of jointed media than routine single hole packer tests which results provides only an "isotropic equivalent coefficient" of permeability.