22-09-2014, 01:32 PM
Abstracts: Over the last 20 years, there has been a lot of progress made in understanding the interaction between rock mass behavior and ground support systems. One of the fundamental rules for designing a successful support system is to select support elements best suited to the anticipated ground behavior. For example, highly deformable rock masses and burst-prone conditions require a soft support systems while stiff support should be used in non-brittle ground where low deformation is anticipated. Numerous support elements have been developed to accommodate for a range of rock mass behavior. The theoretical basis for designing support systems is often derived from a demand-capacity analysis whereby the capacity of the support system is extrapolated from laboratory testing while the demand can be estimated using a variety of techniques ranging from simple gravity of wedges to sophisticated discrete element numerical modeling. As a result of the complexity and variability of rock mass such techniques relying on estimation of demand for the support system have important limitations. Rules of thumb and empirical approaches, despite their shortcomings, are still widely used because of their simplicity and robustness.