ABSTRACT

Rock discontinuities are characterized by their orientations, spacing and persistency, and surface topography. Water content is a ratio to indicate the amount of water a rock contains. Water content can be either the volumetric or the gravimetric fraction of the total rock that is filled with liquid water. Rock discontinuity spacing is also measured though direct measurement of scan lines on the outcrops of rock mass or photogrammetric methods. The photos of the surface are used to quantify the surface morphology of rock discontinuities. The clayey materials as filling in discontinuities are related either to shearing of discontinuities in the geological past or to weathering or hydrothermal alteration of rock material adjacent to the discontinuity walls. The number of discontinuity sets plays a major role on the overall behavior of rock mass as well as its stability and thermo-hydro-mechanical properties.