In this work the pure bending mode was assumed. It is likely that the true mode contains eithercompression or tension as well. This may change the behaviour of the shotcrete layer(compression makes it stronger for bending and for shear while tension weakens it in both). Whenshotcreting is done reasonable distance away from the excavation end then the linear elasticassumption is reasonable. The jaggedness of the rock surface causes local concentration pointsfor stresses which may generate localized failures. If the jaggedness is random, this effect shouldbe negated by the low probability of them occurring in a large enough area. However, they maycause small scale damage to the shotcrete layer