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Keywords: conventional tunnelling, lining performance, fine-grained soil, fragile failure.

Summary

This paper presents a numerical study regarding the actual load taken by the primary and secondary tunnel lining in cemented fine-grained stiff soils, for several construction conditions aiming at establishing more rational design criteria. A 3.5 km long tunnel to be built in a densely populated northwest area of Mexico City, was considered as a case study. As a result of the lack of experimental data, the strength and deformability parameters were established indirectly through empirically-derived correlations. Then, a series of tri-dimensional finite difference models, developed with the program FLAC3D, were used to simulate the tunnel construction, and to compute the ground settlements and internal forces and displacements acting both at the primary and secondary tunnel linings. Interaction diagrams were used to study the lining performance. Several advancement lengths were evaluated, as well as primary and secondary lining thicknesses. From the results gathered in this study, three key construction stages were identified and analyzed: 1) when the tunnel has no lining, 2) when only the primary lining is working, and 3) when the secondary lining is placed. The corresponding displacements in each of these stages are on average 50, 47, and 3 percent of the total displacement respectively. Therefore, most of the load is taken by the primary lining. In order to optimize the lining design, it is recommended to have a more robust primary lining, and a thinner secondary lining.

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Front Page Browse CCP CSETS CTR IJRT Other Authors Search Purchase Guide FAQ Contact us	Civil-Comp Proceedings ISSN 1759-3433 CCP: 108 PROCEEDINGS OF THE FIFTEENTH INTERNATIONAL CONFERENCE ON CIVIL, STRUCTURAL AND ENVIRONMENTAL ENGINEERING COMPUTING Edited by: J. Kruis, Y. Tsompanakis and B.H.V. Topping Paper 253 Lining Performance in Conventional Excavating Tunnels J.M. Mayoral, D. Vital, N. Sarmiento and D. de la Rosa Institute of Engineering, National University of Mexico, Mexico doi:10.4203/ccp.108.253 purchase the full-text of this paper Full Bibliographic Reference for this paper J.M. Mayoral, D. Vital, N. Sarmiento, D. de la Rosa, "Lining Performance in Conventional Excavating Tunnels", in J. Kruis, Y. Tsompanakis, B.H.V. Topping, (Editors), "Proceedings of the Fifteenth International Conference on Civil, Structural and Environmental Engineering Computing", Civil-Comp Press, Stirlingshire, UK, Paper 253, 2015. doi:10.4203/ccp.108.253 Keywords: conventional tunnelling, lining performance, fine-grained soil, fragile failure. Summary This paper presents a numerical study regarding the actual load taken by the primary and secondary tunnel lining in cemented fine-grained stiff soils, for several construction conditions aiming at establishing more rational design criteria. A 3.5 km long tunnel to be built in a densely populated northwest area of Mexico City, was considered as a case study. As a result of the lack of experimental data, the strength and deformability parameters were established indirectly through empirically-derived correlations. Then, a series of tri-dimensional finite difference models, developed with the program FLAC3D, were used to simulate the tunnel construction, and to compute the ground settlements and internal forces and displacements acting both at the primary and secondary tunnel linings. Interaction diagrams were used to study the lining performance. Several advancement lengths were evaluated, as well as primary and secondary lining thicknesses. From the results gathered in this study, three key construction stages were identified and analyzed: 1) when the tunnel has no lining, 2) when only the primary lining is working, and 3) when the secondary lining is placed. The corresponding displacements in each of these stages are on average 50, 47, and 3 percent of the total displacement respectively. Therefore, most of the load is taken by the primary lining. In order to optimize the lining design, it is recommended to have a more robust primary lining, and a thinner secondary lining. purchase the full-text of this paper (price £20) go to the previous paper go to the next paper return to the table of contents return to the book description purchase this book (price £75 +P&P)
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