Mechanical model for operational loads prediction on shield cutter head during excavation

This paper presents a mechanical model to predict the operational loads acting on the cutter head of shield tunnel machine during excavation based on contact mechanics theory, in which the cutter head is considered as a rigid cylinder punch and the soil to be excavated is simplified as an elastic half-space. Then the estimation formulae of the operational loads are obtained and the influence of some key factors including the geological parameters, the radius of the cutter head and especially the excavation penetration can be analyzed based on the proposed model. The results show that the operational loads increase linearly when the machine works with a deeper excavation penetration. The prediction presented in this paper agrees with experimental results given by other researcher. It also can be seen that the geological condition affects both the quantity and the changing rate of loads with the excavation penetration. The proposed model may be a possible and feasible way to predict loads of shield tunnel machine.