Zoned Excavation of an Oversized Pit Close to an Existing Metro Line in Stiff Clay: Case Study
Publication: Journal of Performance of Constructed Facilities
Volume 29, Issue 6
Abstract
Because greenfields available for new developments in congested urban areas are scarce in China, more and more excavations for building basements or other underground facilities (e.g., new metro lines, underground shopping malls, parking garages) have to be carried out in the close proximity of existing metro lines. To ensure project safety, it is essential to know potential adverse effects of excavations on adjacent metro lines in service. Until now, many studies have contributed to the cases of excavations overlying existing tunnels. In contrast, only a few were known for excavations parallel to adjacent existing tunnels. With regard to the responses of existing metro stations to adjacent excavations, few case studies were reported in the literature. Through an extensive field instrumentation program in combination of numerical simulations, this study examines the performance of an oversized deep excavation in stiff clayey deposits and the corresponding responses of the adjacent metro station and twin shield tunnels in service. Taking advantage of the adopted zoned-construction procedure, both wall deflections and ground settlements of this oversized pit were not as significant as those reported in the literature, even smaller than those of long and narrow metro station pits. Consequently, both deformations and displacements of the existing metro line were within acceptable limits, and no obvious structural damage was observed. Throughout the excavation, the two-level island-type metro station exhibited a good structural integrity, which settled uniformly along the transverse direction and tilted slightly along the longitudinal direction. As to the twin shield tunnel linings, the one located within the primary ground influence zone developed considerably larger settlements and deformations than the other one within the secondary influence zone. As a product of the lateral stress relief attributable to soil removal, the tunnel lining experienced apparent elongations in the horizontal direction.
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Acknowledgments
The financial support from the Innovation Program of Shanghai Municipal Education Commission (No. 13ZZ027) is gratefully acknowledged. The great comments and suggestions from the two anonymous reviewers and the Editor are sincerely appreciated.
References
ABAQUS [Computer software]. ABAQUS user manual, ABAQUS.
Brinkgreve, R. B. J., et al. (2002). PLAXIS finite element code for soil and rock analyses, Balkema, Rotterdam, The Netherlands.
Chang, C. T., Suna, C. W., Duannb, S. W., and Hwang, R. N. (2001a). “Response of a taipei rapid transit system (TRTS) tunnel to adjacent excavation.” Tunnelling Underground Space Technol., 16(3), 151–158.
Chang, C. T., Wang, M. J., Chang, C. T., and Sun, C. W. (2001b). “Repair of displaced shield tunnel of the Taipei rapid transit system.” Tunnelling Underground Space Technol., 16(3), 167–173.
Clough, G. W., and O’Rourke, T. D. (1990). “Construction induced movements of in-situ walls.” Geotechnical Special Publication: Design and Performance of Earth Retaining Structures (GSP 25), ASCE, Reston, VA, 439–470.
Devriendt, M., Douthty, L., Morrison, P., and Pillai, A. (2010). “Displacement of tunnels from a basement excavation in London.” Geotech. Eng., 163(3), 131–145.
Di, G. E. (2009). “Design and construction of an over-sized deep excavation by central-island technique.” M.S. thesis, Tongji Univ., Shanghai, China (in Chinese).
Han, J., Zhou, H. T., and Ye, F. (2002). “State of practice review of deep soil mixing techniques in China.”, Transportation Research Board, Washington, DC, 49–57.
Hsieh, P. G., and Ou, C. Y. (1998). “Shape of ground surface settlement profiles caused by excavation.” Can. Geotech. J., 35(6), 1004–1017.
Hu, Z. F., Yue, Z. Q., Zhou, J., and Tham, L. G. (2003). “Design and construction of a deep excavation in soft soils adjacent to the Shanghai metro tunnels.” Can. Geotech. J., 40(5), 933–948.
Huang, X., Huang, H. W., and Zhang, D. M. (2014). “Centrifuge modelling of deep excavation over existing tunnels.” Geotech. Eng., 167(1), 3–18.
Huang, X., Schweiger, H. F., and Huang, H. W. (2013). “Influence of deep excavations on nearby existing tunnels.” Int. J. Geomech., 170–180.
Liao, S. M., Fan, Y. Y., Shi, Z. H., Shao, W., and Kong, X. P. (2013). “Optimization study on the reconstruction and expansion of an underground rail transit center in Shanghai soft ground.” Tunneling Underground Space Technol., 38, 435–446.
Liao, S. M., Liu, J. H., Wang, R. L., and Li, Z. M. (2009). “Shield tunneling and environment protection in Shanghai soft ground.” Tunneling Underground Space Technol., 24(4), 454–465.
Liao, S. M., Peng, F. L., and Shen, S. L. (2008). “Analysis of shearing effect on tunnel induced by load transfer along longitudinal direction.” Tunneling Underground Space Technol., 23(4), 421–430.
Liu, G. B., Jiang, R. J., Ng, C. W. W., and Hong, Y. (2011). “Deformation characteristics of a 38 m deep excavation in soft clay.” Can. Geotech. J., 48(12), 1817–1828.
Liu, G. B., Ng, C. W. W., and Wang, Z. W. (2005). “Observed performance of a multipropped excavation in Shanghai soft clays.” J. Geotech. Geoenviron. Eng., 1004–1013.
Peng, F. L., Wang, H. L., Tan, Y., Xu, Z. L., and Li, Y. L. (2011). “Field measurements and FEM simulation of a tunnel shaft constructed by pneumatic caisson method in Shanghai soft ground.” J. Geotech. Geoenviron. Eng., 516–524.
Shanghai Municipal Engineering Authority. (2000). “Specification for excavation in Shanghai metro construction.” SZ-08-2000, Shanghai, China (in Chinese).
Sharma, J. S., Hefny, A. M., Zhao, J., and Chan, C. W. (2001). “Effect of large excavation on deformation of adjacent MRT tunnels.” Tunnelling Underground Space Technol., 16(2), 93–98.
Shen, S., Han, J., and Du, Y. (2008). “Deep mixing induced property changes in surrounding sensitive marine clays.” J. Geotech. Geoenviron. Eng., 845–854.
Shen, S., Wang, Z., Yang, J., and Ho, C. (2013). “Generalized approach for prediction of jet grout column diameter.” J.Geotech. Geoenviron. Engineering, 2060–2069.
Shen, S. L., Wu, H. N., Cui, Y. J., and Yin, Z. Y. (2014). “Long-term settlement behaviour of metro tunnels in the soft deposits of Shanghai.” Tunneling Underground Space Technol., 40, 309–323.
Sun, Y., Xu, Y. S., Shen, S. L., and Sun, W. J. (2012). “Field performance of underground structures during shield tunnel construction.” Tunneling Underground Space Technol., 28(1), 272–277.
Tan, Y., and Li, M. W. (2011). “Measured performance of a 26 m deep top-down in excavation in downtown Shanghai.” Can. Geotech. J., 48(5), 704–719.
Tan, Y., and Wang, D. (2013a). “Characteristics of a large-scale deep foundation pit excavated by the central-island technique in Shanghai soft clay. I: Bottom-up construction of the central cylindrical shaft.” J. Geotech. Geoenviron. Eng., 1875–1893.
Tan, Y., and Wang, D. (2013b). “Characteristics of a large-scale deep foundation pit excavated by the central-island technique in Shanghai soft clay. II: Top-down construction of the peripheral rectangular pit.” J. Geotech. Geoenviron. Eng., 1894–1910.
Tan, Y., and Wang, D. (2013c). “Structural behaviors of large underground earth-retaining systems in Shanghai. I: Unpropped circular diaphragm wall.” J. Perform. Constr. Facil., 04014058.
Tan, Y., and Wang, D. (2013d). “Structural behaviors of large underground earth-retaining systems in Shanghai. II: Multipropped rectangular diaphragm wall.” J. Perform. Constr. Facil., 04014059.
Tan, Y., and Wei, B. (2012a). “Observed behaviors of a long and deep excavation constructed by cut-and-cover technique in Shanghai soft clay.” J. Geotech. Geoenviron. Eng., 69–88.
Tan, Y., and Wei, B. (2012b). “Performance of an overexcavated metro station and facilities nearby.” J. Perform. Constr. Facil., 241–254.
Tan, Y., Wei, B., Diao, Y. P., and Zhou, X. (2014a). “Spatial corner effects of long and narrow multi-propped deep excavations in Shanghai soft clay.” J. Perform. Constr. Facil., 04014015(17).
Tan, Y., Wei, B., Zhou, X., and Diao, Y. P. (2014b). “Lessons learned from construction of Shanghai metro stations—Importance of quick excavation, promptly propping, timely casting and segmented construction.” J. Perform. Constr. Facil., 04014096.
Wei, S. (2014). “Investigation on safety and protection criteria of metro stations adjacent to deep excavations.” M.S. thesis, Dept. of Geotechnical Engineering, Tongji Univ., Shanghai, China (in Chinese).
Wei, S., Liao, S., Zhu, Y., Li, X., and Tan, Y. (2013). “Parametric study on the effect of deep excavation on the adjacent metro station in Suzhou.” IACGE 2013, ASCE, Chengdu, China, 223–230.
Zhang, D. F., Tong, L. Y., Liu, S. Y., Gao, X. N., and Lou, C. B. (2013b). “Deformation behavior of supporting structures of deep excavations in Suzhou subway line 1.” Chin. J. Underground Space Eng., 9(s2), 1961–1965.
Zhang, J. F., Chen, J. J., Wang, J. H., Zhu, Y. F. (2013a). “Prediction of tunnel displacement induced by adjacent excavation in soft soil.” Tunnelling Underground Space Technol., 36, 24–33.
Zheng, G., and Wei, S. W. (2008). “Numerical analyses of influence of overlying pit excavation on existing tunnels.” J. Cent. South Univ. Technol., 15(s2), 069–075.
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Published In
Journal of Performance of Constructed Facilities
Volume 29 • Issue 6 • December 2015
Copyright
© 2014 American Society of Civil Engineers.
History
Received: Mar 8, 2014
Accepted: Jul 10, 2014
Published online: Sep 23, 2014
Discussion open until: Feb 23, 2015
Published in print: Dec 1, 2015
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