ABSTRACT
Discontinuities have a profound effect on the deformability and strength of rock masses. Characterization of a rock mass depends not only on the nature of the rock material, but also on the discontinuities which are pervasive throughout almost all natural rock. The presence of discontinuities has long been recognized as an important factor influencing the mechanical behavior of rock masses. The existence of one or several discontinuity sets in a rock mass creates anisotropy in its response to loading and unloading. Also, compared to intact rock, jointed rock shows reduced shear strength along planes of discontinuity, increased deformability parallel to those planes, and increased deformability and negligible tensile strength in directions normal to those planes.
