Evaluation of Deformation Modulus for the Jointed Rock Masses Using Equivalent Continuum Approach

Abstract

The rock masses are intercepted by several geological discontinuities that make them different from other engineering materials. The response of rock masses during excavation of ground for development of large engineering structures such as dams, tunnels, underground caverns etc. is very complicated. As the engineering structures are significantly larger than the rock blocks with discontinuities, therefore the rock masses may be represented in form of an equivalent continuum. Rock masses in this form are being utilized to determine important engineering properties such as compressive strength and modulus of deformation by means of empirical relationships. These properties have been used as an alternative for in-situ testing for designing of engineering structures. This paper evaluates the deformation modulus (Ed) of jointed rock masses by means of various available relationships for three rock types namely metavolcanics, dolomite and slate occurring extensively in Lesser Himalayan region of northern India. The determined empirical results are validated with the field investigation outputs. An attempt has also been made to work out new empirical relationships based on the field results.