The design of retaining walls supported by tiebacks is often based on approximate limit equilibrium calculations. In this Paper the results of conventional limit equilibrium free and fixed earth support methods are compared with those of a finite element study. Predictions of both maximum bending moments and final anchor forces are compared, while the finite element study is also used to isolate and reveal the influence of initial soil stress conditions, construction procedure and initial prestressing force level. Generally it was found that for the case of an active initial stress condition K_a or in low K_o soils limit equilibrium approaches provided an overestimate of almost 50 percent of the anchor force. The wall bending moment predictions of finite element and fixed earth support method on the other hand, are approximately of the same magnitude but 45 percent lower than the one predicted by the free earth support method. Moreover, the level of initial prestressing force of the tiebacks plays a significant role for both displacement vector, wall bending moment and final anchor force. It was found that an initial prestressing level of approximately 35 percent can be considered as an optimal solution.

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