Reasonable design method of shield tunnel lining under internal water pressure

N. OKANO¹, S. KONISHI¹, K. KOBAYASHI², A. KOENUMA², K. OHISHI³, A. DAN⁴
1.Railway Technical Research Institute; 2. Tokyo Metropolitan Government; 3. Teito Rapid Transit; 4. Nippon Civic Consulting Engineers Co., Ltd.
Modern Tunneling Science and Technology: Proceedings of the International Symposium on Modern Tunneling Science and Technology. Swets & Zeitlinger. October, 2001. ISBN 90 2651 860 9

Key words: shield tunnel, segment lining, underground reservoir, internal water pressure, beam-spring model, lining design

Background
The Tokyo Metropolitan Government plans to construct the Kanda River/Loop 7 Underground Regulation Pond Work (2nd phase). The pond will be constructed by the shield tunneling method and the completed tunnel will occasionally be under internal water pressure. Therefore, the shield tunnel will have a different load condition from that of regular railway, transmission line, or other tunnels.

Research Summary
We focused on the sub-grade response and spring and tensile rigidity of segment joints in a beam-spring analysis model for the structural design of segments under internal water pressure. Using the beam-spring analysis model, we prepared an economical cross-sectional design for the shield tunnel. The dimensions were: external diameter 13.7 m, internal diameter 12.5 m, depth of overburden 41.4 m.