Estimation of natural ground behavior ahead of face by measuring deformation which utilized TBM drift tunnel
In Japan, 3-lane highway is building by Japan Highway Public Corporation. The area of 3-lane tunnel cross-section is about 200 m2 and is about 2 times as large as the cross-sectional area of a standard mountain tunnel in Japan. The tunnel construction method of excavation with which tunnel boring machine (TBM) drift tunnel (the diameter is 5 m) is made preceding was newly adopted as the standard excavation method of mountain tunnel. Then the cross-section of its TBM drift tunnel is enlarging by excavation of NATM. In order to measure all displacement of axial direction of tunnel continually during excavation, the deformation is measured inside TBM drift tunnel until the enlarged excavated tunnel face reached. When the enlarged tunnel face arrived just before monitoring point, the measuring points have been placed at the wall of enlarged tunnel at less than one-round length. Then displacement is measured continually. The following things can be appreciated from the result this time. (1) All amount of displacement can be predicted in general using the displacement until the enlarged tunnel face reaches, and using the distance of changing point. (2) The tendency of displacement, such as quantity of displacement, is caught by prediction. (3) The behavior of a natural ground can appreciate by measurement the displacement of a series from before tunnel face attainment to after passage. (4) The quality of ahead natural ground can be appreciated relatively. (5) The continuous displacement of the tunnel vertical section direction can be appreciated with time by preparing many measuring points. (6) The properties of a natural ground (such as appearance elastic coefficient) can be presumed. (7) Examination in numerical analysis is attained. Therefore, to predict of behavior of natural ground after enlarge becomes possible, utilizing deformation monitoring in TBM drift tunnel, on the basis of behavior of excavated natural ground. By continuous deformation measuring from the enlarged excavation before and after, continuous estimation of natural ground behavior, prediction generally the last displacement from displacement of enlarge excavation immediately and evaluation the good or bad condition of tunnel face and natural ground ahead of face relatively become possible. Besides effect of TBM drift tunnel thought about heretofore, it is possible to add role of estimate of mechanical property of natural ground, evaluate behavior of natural ground ahead of face before enlarge excavation, necessity examination of simple reinforcement and auxiliary method get possible. (A). "Reprinted with permission from Elsevier". For the covering abstract see ITRD E124500.
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Availability:
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Authors:
- ITO, T
- AKAGI, W
- SHIROMA, H
- NAKANISHI, A
- KUNIMURA, S
- Publication Date: 2004-7
Language
- English
Media Info
- Pagination: 527-8
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Serial:
- TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY. UNDERGROUND SPACE FOR SUSTAINABLE URBAN DEVELOPMENT. PROCEEDINGS OF THE 30TH ITA-AITES WORLD TUNNEL CONGRESS SINGAPORE, 22 - 27 MAY 2004
- Volume: 19
- Issue Number: 4-5
- Publisher: Elsevier
- ISSN: 0886-7798
Subject/Index Terms
- TRT Terms: Conferences; Dislocation (Geology); Ground settlement; Highways; Measurement; Tunnels
- Geographic Terms: Japan
- ITRD Terms: 8525: Conference; 2755: Highway; 8053: Japan; 6136: Measurement; 5483: Movement; 5792: Settlement; 3374: Tunnel
- Subject Areas: Bridges and other structures; Design; Highways; I25: Design of Tunnels;
Filing Info
- Accession Number: 01011673
- Record Type: Publication
- Source Agency: Transport Research Laboratory
- Files: ITRD
- Created Date: Dec 19 2005 3:24PM