Present status and technology of shield tunneling method in Japan

Recently in Japan, it has often been necessary to construct tunnels under more severe conditions and to develop new techniques. However, present design techniques cannot appropriately reflect the construction techniques; and thus, traditional methods are still often used. On account of the well-balanced progress between construction and design in the shield tunneling method, an innovation of the design technique is required. This paper shows an outline of the shield tunnel technique at present, behavior of shield tunnels in-site, and improvements required for design. (C) 2003 Elsevier Science Ltd. All rights reserved.