ABSTRACT
A simulation based procedure is presented for determining the rock mass demand of excavations in blocky rock. The procedure has been developed for use in the design of trial reinforcement and support schemes. It comprises a sequence of deterministic and probabilistic analyses of block shape, size and stability which results in a series of relative frequency distributions for the demand characteristics of the removable unstable blocks of rock that might possibly form at the excavation surface. Geometric constraints on block shape and size, imposed by the rock structure and the excavation, are introduced into the simulation process in an attempt to reduce the number of realisations required and increase simulation efficiency. Guidelines are given on the use of the relative frequency distributions in the selection and dimensioning of trial rock improvement schemes.
