Finite element analysis of jointed rock masses reinforced by fully-grouted bolts and shotcrete lining

This paper presents the formulation of an equivalent constitutive model for jointed rock masses reinforced by fully-grouted bolt and shotcrete lining and its implementation in a finite element program. This model takes into consideration the elasto-viscoplastic behavior of the rock masses as well as the contribution of the bolt and lining to both the stiffness and shear resistance of the jointed rock masses. The equivalent model and corresponding software are verified by comparison to conventional numerical models which consider the individual contribution of the reinforcement. The relationship between the constitutive parameter “effective height” and the thickness of the lining is evaluated using the ANN approach. Finally, the interest of the proposed model is illustrated through its application for the analysis of the excavation of an underground cavern in a hydropower project.