ABSTRACT
The effectiveness of a particular reinforcement scheme in terms of its density and length can be assessed using empirical strategies, theoretical methods and geotechnical instrumentation (Windsor and Thompson, 1993). In addition, detailed stability analysis may now also include the calibration of a numerical model program to simulate the excavation sequences in order to assess the role of stress change on the rock mass environment. Three dimensional numerical modelling results can then be used to determine the overall stability around underground excavations, where zones of damage, or failure can be estimated and then used to determine the required length and capacity of a reinforcement scheme. The required input parameters consist of the in-situ stress profile with depth, the strength and deformational properties of the rock mass as well as the excavation steps and their sequence.
