STUDY ON SURCHARGE DUE TO BUILDING LOAD IN CONSIDERATION OF TUNNEL FLEXIBILITY AND BOUNDARY CONDITIONS BETWEEN TUNNEL AND GROUND

トンネルと地盤の剛性と境界条件を考慮した上載荷重の影響評価と算定モデルの検討

Deep underground tunnels should be designed with some surcharge in consideration of the building load of overlying structures such as skyscrapers. However, current design methods do not consider the concept of load share between the ground and the tunnel. Therefore, tunnel linings need to be designed such that they have high rigidity and bearing force. To overcome this problem, in this study, the authors conducted centrifuge model tests to clarify the load share mechanism in consideration of tunnel flexibility, ground elasticity, and boundary conditions between the tunnel and the ground. In a rigid tunnel, the surcharge was supported by the tunnel, whereas that in a flexible tunnel was supported by the ground. As a result, the cross-sectional forces of the flexible tunnel were smaller than those of the rigid tunnel. This finding indicates the importance of introducing the load share concept in the model used for calculating the surcharge. A 2D theoretical model that considers the elasticity of the tunnel and the ground was studied for calculating the surcharge. The experimental and FEM (finite element method) analysis results confirmed its applicability to elastic ground such as soft rock but not to soft ground lacking tension strength.　大深度トンネルに適用される建築物荷重の合理的な評価方法の確立と検証を目的として遠心模型実験を行った．実験ではトンネルの曲げ剛性や，トンネルと地盤の境界条件をパラメータとして，上載荷重作用時にトンネルに発生するひずみや変形，周辺地盤の土圧を計測した．その結果，曲げ剛性が低いトンネル模型の場合や，トンネル剛性が同じ条件ではトンネルと地盤が一体となって挙動する場合に断面力変化量が小さくなる傾向が確認できた．また，建築物荷重の評価方法として既往の弾性解の適用性を検討した．その結果，実験結果を一部再現できたものの，弾性体ではない砂地盤を使用した実験結果とは完全には一致しなかった．一方，現行の断面力算定方法では，曲げ剛性の小さいケースで上載荷重を過大に評価する可能性があることを確認した．

• Record URL:
  https://doi.org/10.2208/jscejte.71.54
• Summary URL:
  http://scholar.google.com/scholar_lookup?title=STUDY+ON+SURCHARGE+DUE+TO+BUILDING+LOAD+IN+CONSIDERATION+OF+TUNNEL+FLEXIBILITY+AND+BOUNDARY+CONDITIONS+BETWEEN+TUNNEL+AND+GROUND&author=H.+SUGIYAMA&author=T.+OKUNO&author=K.+NISHIMURA&publication_year=2015
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/21856575
• Authors:
  • SUGIYAMA, Hirokazu
  • OKUNO, Tetsuo
  • NISHIMURA, Kazuo
• Publication Date: 2015

Language

• English
• Japanese

Media Info

• Media Type: Web
• Pagination: pp 54-65
• Serial:
  • Journal of Japan Society of Civil Engineers, Ser. F1 (Tunnel Engineering)
  • Volume: 71
  • Issue Number: 1
  • Publisher: Japan Society of Civil Engineers
  • ISSN: 2185-6575
  • Serial URL: https://www.jstage.jst.go.jp/browse/jscejte/-char/en

Subject/Index Terms

• TRT Terms: Centrifuges; Design; Loads; Structures; Tension; Tunnel lining; Tunneling
• Subject Areas: Bridges and other structures; Construction; Design; Highways; Railroads; I25: Design of Tunnels; I54: Construction of Tunnels;

Filing Info

• Accession Number: 01571539
• Record Type: Publication
• Source Agency: Japan Science and Technology Agency (JST)
• Files: TRIS, JSTAGE
• Created Date: Jul 28 2015 4:01PM