A STUDY ON MECHANICAL BEHAVIOR OF SUPPORT ELEMENTS INDUCED BY SHAFT SINKING

ショートステップ工法による立坑掘削に伴う支保部材の力学挙動に関する研究

Japan Atomic Energy Agency has been excavating three deep shafts through soft sedimentary rock in the Horonobe Underground Research Laboratory. In this paper, the authors discussed change in stress and the stress distribution in a concrete lining and steel arch ribs induced by the 6.5 m diameter shaft sinking. They conducted not only field measurements of stress in support elements at a depth of around 220 m but also three-dimensional numerical analysis which models the shaft excavation procedure such as timing of installation of support elements and setting and removal of a concrete form. As a result, it was clarified that more than 10 MPa difference in circumferential stress occurred in a 2 m high and 400 mm thick concrete lining due to anisotropy of initial stress and three-dimensional effect of an excavation face. It was also found that a concrete lining gradually deformed from an original cylindrical form to a shape of an ellipsis with the long axis parallel to the direction of the minimum horizontal principal stress after a concrete form was removed.　幌延深地層研究所にて新第三紀堆積岩に施工中の東立坑（内径6.5m）の深度約220mを対象として，ショートステップ工法における覆工コンクリートと鋼製リング支保工の応力の変化，分布および発達機構を，現場計測と数値解析によって分析した．現場計測では，支保部材の初期地圧の水平面内の主応力方向の縦断面内に複数個の計器を設置し，応力計測を行った．数値解析では，立坑の施工手順を詳細に再現した三次元逐次掘削解析を実施した．その結果，覆工コンクリート内には，初期地圧の水平面内の異方性と深度方向の応力再配分の程度の差によって，10MPa以上の円周方向応力の差が生じることや，覆工コンクリートは，水平面内にて最小主応力方向を長軸とする楕円形で，上側に比べて下側がすぼむようなすり鉢状の変形モードを呈すことを明らかにした．

• Record URL:
  • https://doi.org/10.2208/jscejte.68.7
• Summary URL:
  • http://scholar.google.com/scholar_lookup?title=A+STUDY+ON+MECHANICAL+BEHAVIOR+OF+SUPPORT+ELEMENTS+INDUCED+BY+SHAFT+SINKING&author=K.+TSUSAKA&author=D.+INAGAKI&author=Y.+HATSUYAMA&author=M.+KOIKE&author=T.+SHIMADA&author=Y.+IJIRI&publication_year=2012
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/21856575
• Authors:
  • TSUSAKA, Kimikazu
  • INAGAKI, Daisuke
  • HATSUYAMA, Yoshihiro
  • KOIKE, Masashi
  • SHIMADA, Tomohiro
  • IJIRI, Yuji
• Publication Date: 2012

Language

• English
• Japanese

Media Info

• Media Type: Digital/other
• Features: Figures; References; Tables;
• Pagination: pp 7-20
• Serial:
  • Journal of Japan Society of Civil Engineers, Ser. F1 (Tunnel Engineering)
  • Volume: 68
  • 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: Concrete; Deformation; Mechanics; Shaft sinking; Stresses; Supporting; Tunnel lining; Underground structures
• Geographic Terms: Japan
• Subject Areas: Bridges and other structures; Construction; Highways; I54: Construction of Tunnels;

Filing Info

• Accession Number: 01504710
• Record Type: Publication
• Source Agency: Japan Science and Technology Agency (JST)
• Files: TRIS, JSTAGE
• Created Date: Jan 27 2014 9:40AM