SPATIAL SIMULATION OF ROCK STRENGTH PROPERTIES USING A MARKOV-BAYES METHOD

In most rock engineering projects, actual measurements of rock strengt hs often are limited to a few observations over large volumes of the r ock mass. However, these few data can be complemented by secondary inf ormation such as qualitative lithology descriptions or drilling charac teristics, which typically are available across much of the study regi on. A Markov-Bayes method can be used to combine these types of inform ation to produce spatial simulations of rock strength properties. A ca se study that illustrates this simulation procedure has been completed for the siltstone roof in a selected 6x18-m area of an underground co al mine. Three-dimensional simulations, or stochastic images, of the u niaxial compressive strength and the modulus of elasticity were genera ted using hard data from four core holes and secondary data in the for m of averaged specific energy of drilling values (SED) from 95 rock-bo lt holes. Such images not only provide a probabilistic model of rock s trength, but also describe the natural variability and spatial fluctua tions as well.