1999 Fiscal Year Final Research Report Summary
On the Tunnel Support Mechanism of Shotcrete
| Project/Area Number |
10555168
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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 |
Geotechnical engineering
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
TAMURA Takeshi Fiaculty of Eng., Kyoto University Prof., 工学研究科, 教授 (30026330)
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| Co-Investigator(Kenkyū-buntansha) |
KIMURA Makoto Fiaculty of Eng., Kyoto Univesity Assoc. Prof., 工学研究科, 助教授 (30177927)
TATEYAMA Kazuyoshi Fiaculty of Eng., Kyoto University Assoc. Prof., 工学研究科, 助教授 (10179731)
ADACHI Toshihisa Fiaculty of Eng., Kyoto University Prof., 工学研究科, 教授 (20026173)
KOBAYASHI Shun-rchi Fiaculty of Eng., Kyoto Univesity Res. Assoc., 工学研究科, 助手 (10243065)
KISHIDA Kiyoshi Fiaculty of Eng., Kyoto Univesity Res. Assoc., 工学研究科, 助手 (20243066)
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| Project Period (FY) |
1998 – 1999
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| Keywords | Tunnel / NATM / Earth Pressure / Shotcrete / Lining / Overburden / Loothening / Ground Reaction |
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| Research Abstract |
The mechanical effect of the interaction between the shotcreting and the ground is studied from a view point of the tunnel support stability. A serial set of rigid bars jointed through the bending springs are adopted for a model of the lining while the constant coefficient of subgrade reaction is assumed for the ground. A lot of parametric numerical analyses are done by changing the width of shotcreting, the coefficient of the lateral earth pressure, the overburden and the shape of tunnel section. It is shown that the subgrade reaction is essential for the tunnel stability and that even a thin shotcrete lining supports the surrounding ground if an adequate amount of the subgrade reaction is expected. Other conclusions are as follows.
1) The sugrade reaction reduces the bending moment of the shotcrete lining by controlling the deformation around the tunnel.
2) The thin shotcrete lining may cause a large amount of bending moment.
3) The thin shotcrete lining is preferred unless the buckling occurs.
4) Even when bending failure occurs in the shotcrete lining, no serious damage is resulted if a sufficient ground reaction is expected.
A further research is required concerning the tunnel stability since the present study was done through a very simple mechanical model.
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