Chapter 10 - Rock Mass Index

Abstract

There is no single parameter that can fully designate the properties of jointed rock masses. Various parameters have different significance, and only in an integrated form can describe a rock mass satisfactorily. The rock material is also important if the joints are discontinuous. In addition, the rock description includes the geology and the type of material at the site, although rock properties in many cases are downgraded by joints. The properties of rocks have a profound influence on the formation and development of joints. Petrological data can make an important contribution toward the prediction of mechanical performance, provided that one looks beyond the rock names at the observations on which they are based. This chapter discusses the benefits of rock mass index in mechanics and rock engineering: enhances the accuracy of the input data required in rock engineering by its systematic approach of rock mass characterizations and easily used for rough estimates when limited information about the ground condition is available, for example, in early stages of a feasibility design of a project where rough estimates are sufficient.