Study on shield behaviour by 3-D shield simulator

Automatic shield control systems have been developed based on empirical relationships during the past decade. But they do not have a precise theoretical background. Therefore, it is difficult to predict the shield behaviour. A model of loads acting on a shield has been developed to address this problem. The model was extended to study the effect of using a copy cutter attached on the cutter face, which can adjust in length and position to increase the competence of the excavation. The copy cutter effect was evaluated by adding the excavation area of the copy cutter to that of the cutter face. The shield behaviour was obtained by considering of equilibrium conditions. The results show reasonable simulations of shield position and shield behaviour.