A generalized procedure for the optimum design of nailed soil slopes

A new method is proposed for the optimum design of nailed soil slopes. A rigorous method of stability analysis, namely the Janbu's method, is modified in the limit equilibrium formulation, considering the effect of reinforcement. Only the tensile resistance of the reinforcement is included and the effects of shear and bending neglected. The total reinforcement force required to raise the factor of safety to a desired value has been minimized with the inclinations of the reinforcement and the distribution of the reinforcement forces as decision variables. In order to illustrate the efficacy of the proposed method, the results are compared with the available solutions. The effect of the number and relative locations of the reinforcements on the amount of reinforcement required, is studied. The lengths of reinforcement required to raise the factor of safety to various desired values and the corresponding optimum designs are presented. The acceptability of the critical surface is verified, by ensuring that the shear and normal stresses are positive along the critical surface.