Abstract
Nowadays, articulated shield becomes popular to construct tunnels with curved alignments. To steer the articulated shield, it is necessary to determine the operation on jack, copy cutter and articulation mechanism. But since these three functions have a high co-linearity to shield behaviour, it is difficult to obtain unique operational parameters at once. Therefore, the authors developed a numerical method to determine the copy cutter length and the articulation angle uniquely, based on geometric conditions under some constraint conditions. This paper shows an example of the application of the proposed method to a 3 dimensional compound alignment and discusses the validity of the proposed model. As conclusions, the followings were found: 1) the articulation angle depends on shield dimension, tunnel alignment and operation rules of shield rotation; 2) the copy cutter length distributes across the major normal direction of the tunnel about a half of the skin plate area; and 3) the analysis results demonstrate that the proposed method can provide articulation angle and copy cutter length and range reasonably from the view point of geometric conditions.
