Analytical Design of Rock - Bolt Systems

1.INTRODUCTION Some forty years ago, most opening supports and reinforcements were designed using empirical rules defining ground loads acting on the supporting structures. This approach is still popular and interest in it has been renewed by the use of rock mass classification systems (Barton et al. 1974, Bieniawski, 1974,1976,1989). Correlations between rock mass conditions and the type of support used are based on case histories. This approach perpetuates existing practice, even if over-conservative or unsatisfactory. Most recent underground excavation design relies on more elaborate analysis of the complex rock –support interaction. Moreover, the effect of geometry of opening has to be allowed for. A new concept of RRE (Rock-mass, Rock-bolt, Excavation) which will be developed in thesis, is intended to cover all parameters involving in design of a proper reinforcement system. This concept must take into account not only the properties of rock mass, but also the structure behavior of the reinforcing structure (element) and the opening geometry. Stresses and displacements in the rock mass surrounding openings depend upon the rock mass properties, the in-situ initial stress field, opening shape, and the type (stiffness) of This technical article has been submitted to Rock Mechanics’ research and development (R&D) of mining engineering department of Middle East Techical University as an advanced study.