2002 Fiscal Year Final Research Report Summary
Some Investigations on Cracking of the Tunnel in Cold Region
| Project/Area Number |
12555131
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
構造工学・地震工学
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| Research Institution | HOKKAIDO UNIVERSITY |
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Principal Investigator |
MIKAMI Takashi Hokkaido Univ., Grad. School of Eng., Prof., 大学院・工学研究科, 教授 (00002303)
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| Co-Investigator(Kenkyū-buntansha) |
SUTOH Atsush Chizaki Kogyo Co., Ltd, Struc. Div., Chief Engineer, 土木技術部, 主任研究員
KOIKE Akio Docon Consultants, Soil Div., Engineer., 地質部, 研究員
NAWA Toyoharu Hokkaido Univ., Grad. School of Eng., Assoc. Prof., 大学院・工学研究科, 助教授 (30292056)
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| Project Period (FY) |
2000 – 2002
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| Keywords | Road tunnel / Cold region / Tunnel lining / Thermal cracking / Data mining / Heat insulator / Semi-variogram / Design method |
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| Research Abstract |
The project is summarized as follows :
(1) Temperature can be defined from homogeneous spatial processes by means of a linear transformation, and the design temperature for tunnel heat insulator can be interpolated by Semi-Variogram using a stochastic algorithm. A comparison of the estimated design temperature and the observed temperature of actual data shows that the proposed method yields very good results.
(2) The periodic changes of atmospheric temperature can be transformed to a moving mean value and narrowing amplitude due to distance from the entrance of the tunnel.
(3) It is found that data mining procedure using neural network is useful for finding the cause of cracks in the tunnel lining.
(4) A numerical method is developed for analyzing for the one-dimensional moving boundary problem in semi-infinite region. The method is useful for determining the depth of the frozen ground behind tunnel lining. A comparison with other solutions suggests that the proposed method provide satisfactory accuracy.
(5) In order to investigate the mechanics of thermal cracking in the tunnel lining, heat transfer and stresses are determined using the two-dimensional finite element method and employing interface element for the heat insulator. A concrete model including ageing effects and time-dependent properties is adopted. It is made clear that the elastic modulus of concrete in early ages and thermal conductivity of concrete are sensitive to thermal cracking.
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Research Products
(24 results)
