ABSTRACT
Shaft design receives little attention in the mining and civil engineering literature, and shafts are still constructed predominately on the basis of precedent and prior experience. One of the reasons for this situation is the lack of well established geotechnical design criteria which could define procedures to delineate the disturbed (yielded or fractured) rock zone, DRZ, and support requirements. Determination of stress distributions, and the extend of the DRZ for rectangular and the circular shafts are briefly discussed. In a study of the empirical design methods, adjustments to the basic Rock Mass Rating, RMR, for the effect of the orientation of the discontinuities and induced stresses in shaft structures are introduced. Finally, a general procedure for support design is presented.
