بررسی تاثیر فشار جبهه‌کار بر نشست سطح زمین در تونلسازی مکانیزه در زمین نرم- مطالعه‌ی موردی: تونل قطعه‌ی شرقی- غربی خط 7 متروی تهران

نوع مقاله: مقاله پژوهشی

نویسندگان

1 دانش‌آموخته‌ی کارشناسی‌ارشد مهندسی معدن؛ گرایش استخراج؛ دانشگاه صنعتی شاهرود

2 استادیار؛ دانشکده‌ی مهندسی معدن، نفت و ژئوفیزیک؛ دانشگاه صنعتی شاهرود

3 کارشناس مطالعات مهندسی حین ساخت پروژه تونل قطعه شرقی غربی خط 7 متروی تهران، مهندسین مشاور ساحل

چکیده

در تونل‌های مناطق شهری که بیش‌تر در عمق کم و در بستر خاکی حفر می‌شوند، فشار جبهه‌کار می‌تواند یکی از عوامل پیشگیری کننده‌ی نشست سطح زمین باشد. در پروژه‌ی خط 7 متروی تهران، تونل با ماشین حفاری مکانیزه از نوع متعادل کننده‌ی فشار زمین (EPB) حفر می‌شود. در این تحقیق با تمرکز بر روی چهار مقطع از این تونل، تاثیر فشار جبهه‌کار بر نشست سطح زمین مورد تحلیل قرار گرفته است. فشار جبهه‌کار در چهار حالت فشار اولیه، 5/1، 2 و 4 برابر فشار اولیه و فشار تزریق در 5 حالت بدون اعمال تزریق، برابر فشار جبهه‌کار، 5/0، 1 و 2 بار بیش‌تر از فشار جبهه‌کار با استفاده از نرم‌افزار اجزا محدود PLAXIS3D مورد ارزیابی قرار گرفته است. اعتبارسنجی نتایج با استفاده از ابزاربندی در سطح زمین و بر روی دو مقطع از تونل انجام گرفته است. مقایسه‌ی نتایج مدلسازی و نتایج حاصل از ابزاربندی بیانگر صحت روند مدلسازی است. برای حالت H2D است. همچنین نتایج نشان می‌دهد افزایش 4 برابری فشار جبهه‌کار، حداکثر سبب کاهش 5 میلی‌متری بیش‌ترین نشست می‌شود. بنابراین افزایش فشار جبهه‌کار، میزان نشست را کاهش می‌دهد اما این مقدار بسیار ناچیز است.

کلیدواژه‌ها


عنوان مقاله [English]

Numerical Study of Face Pressure Effect on Surface Settlement in Soft Ground Mechanized Tunneling- A Case Study: Tehran Metro Line 7

نویسندگان [English]

  • Reza Heidari Sheibani 1
  • Shokroullah Zare 2
  • Hosein Mirzaei 2
  • Mohammad Foroughi 3
1 M.Sc. in Mining Engineering; Shahrood University of Technology
2 Assistant Professor; Faculty of Mining Eng., Petroleum and Geophysics; Shahrood University of Technology
3 M.Sc.; Sahel Consulting Engineers
چکیده [English]

Tehran's metro line 7 project has been excavated by an Earth Pressure Balance (EPB) machine. Four sections of the line 7 tunnel have been selected in this study, and the influence of face and backfill grout pressures on surface settlement has been numerically investigated. The obtained numerical results have been confirmed by the monitoring data using the installed instruments on site. Then, the results of various numerical models for different amounts of face pressure and backfill grouting pressure have been discussed. In this research, the influence of backfill grouting pressure is found to be significant.
 
Introduction
Various underground spaces such as tunnels are constructed in urban areas for different purposes. These spaces are often located in soil media near the ground surface. Therefore surface settlement control is a critical task in the construction of these spaces. In EPB mechanized tunneling, the face pressure and backfill grouting pressure are the most important factors to prevent surface settlement.
 
Methodology and Approaches
In this study, the PLAXIS3D software has been employed for carrying out 3D numerical modeling of face pressure influence on the surface settlement. In addition, the Mohr-Coulomb criterion has been considered for geo-mechanical behavior of soil material surrounding the tunnel. In two sections of the tunnel, the results of numerical models have been verified by the data obtained from monitoring instruments installed in the site. In the other two sections of tunnel, four states of face pressure: P=P0 (estimated initial pressure), P=1.5P0, P=2P0 and P=4P0 and for each state, five states of backfill grouting pressure: G=0, G=P, G=P+0.5 bar, G=P+1 bar and G=P+2 bar have been considered and surface settlement in each case has been analyzed.
 
Results and Conclusions
The obtained numerical results show that a %400 increase of face pressure, leads to a decrease of maximum 5 mm in the surface settlement. Thus, the influence of face pressure seems to be trivial but the influence of backfill grouting pressure appears to be significant.

کلیدواژه‌ها [English]

  • Settlement
  • EPB
  • Tehran Subway Tunnel
  • Instruments’ Data
  • Numerical Modeling
[1]     Guglielmetti, V., Grasso, P., Mahtab, A., & Xu, S. (2007). Mechanized Tunneling in Urban Areas: Design Methodology and Construction Control. (V. Guglielmetti, Ed.) London: Taylor and Francis e-Library. ISBN: 978-0-203-393851-5 (eBook).

[2]     Mohkam, M., & Wong, Y. W. (1989). Three Dimensional Stability Analysis of The Tunnel Face Under Fluid Pressure. Numerical Methods in Geomechanics (pp. 2271-2287). Rotterdam: A. A. Balkema.

[3]     Jancsecz, S., & Steiner, W. (1994). Face Support for a Large Mix-Shield in Heterogeneous Ground Conditions. Tunnelling '94: Seventh International Symposium Organized by the Institution of Mining and Metallurgy and the British Tunnelling Society (pp. 531-541). London: Chapman and Hall. ISBN: 9780412598609.

[4]     Broere, W. (1998). Face Stability Calculation for a Slurry Sheild in Hetrogeneous Soft Soils. In Nego, & Ferreira (Ed.), Proceedings of the World Tunnel Congress'98 on Tunnels and Metropolises (pp. 215-218). Sao Paolo, Brazil. Taylor & Francis. ISBN: 9789054109365.

[5]     Atkinson, J. H., & Potts, D. M. (1977). Subsidence above Shallow Tunnels in Soft Ground. Journal of the Geotechnical Engineering Division, 103(4), 307-325.

[6]     Attewell, P. B., & Woodman, J. P. (1982). Predicting the Dynamics of Ground Settlement and its Derivatives Caused by Tunneling in Soil. Ground Engineering, 15(8), 13-22.

[7]     Baligh,  M. (1985). Strain Path Method. Journal of Geotechnical Engineering, 111(9), 1108-1136. http://dx.doi.org/10.1061/(ASCE)0733-9410(1985)111:9(1108).

[8]     Chambon, P., & Corte, J. F. (1994). Shallow Tunnels in Cohesionless Soil: Stability of Tunnel Face. Journal of Geotechnical Engineering, 120(7), 1148–1165. http://dx.doi.org/10.1061/(ASCE)0733-9410(1994)120:7(1148).

[9]     Clough, G. W., Sweeney, B. P., & Finno, R. J. (1983). Measured Soil Response to EPB Shield Tunneling. Journal of Geotechnical Engineering, 109(2), 131-149. http://dx.doi.org/10.1061/(ASCE)0733-9410(1983)109:2(131).

[10] Leca, E. (1989). Analysis of NATM and Shield Tunneling in Soft Ground. Blacksburg: Doctoral Thesis, Virginia Institute and State University.

[11] Hwang, R. N., & Moh, Z. C. (1996). Pore Pressures Induced in Soft Ground due to Tunneling. In R. J. Mair, & R. N. Taylor (Ed.), Proceedings of the International Symposium on Geotechnical Aspects of Underground Construction in Soft Ground (pp. 695-700). Rotterdam: A. A. Balkema. ISBN: 9789054108566.

[12] Matsushita, Y., Iwasakl, Y., Hashimoto, T., & Imanishi, H. (1994). Behavior of Subway Tunnel Driven by Large Slurry Shield. Proceedings of the International Symposium on Geotechnical Aspects of Underground Construction in Soft Ground  (pp. 253-256). Rotterdam: A. A. Balkema.

[13] Chiorboli, M. A., & Marchesili, P. P. (1996). Analysis and Control of Subsidence due to Earth Pressure Shield Tunneling in Pass ante Ferroviario of Milano. In L. Ozdemr (Ed.), Proceedings of the International Conference on North American Tunneling'96 (pp. 97-106). Rotterdam: A. A. Balkema. ISBN: 9054108037.

[14] Suchatvee, S. (2002). Earth Pressure Balance (EPB) Shield Tunneling in Bangkok: Ground Response and Prediction of Surface Settlements Using Artificial Neural Networks. Doctoral Thesis, Massachusetts Institute of Technology (MIT), Department of Civil and Environmental Engineering. http://hdl.handle.net/1721.1/32222.

[15] Crow, M., & Holzhäuser, J. (2003). Performance of Four EPB-TBMs Above and Below the Groundwater Table on the ECIS Project, Los Angeles, CA, USA. In R. A. Robinson, & J. M. Marquardt (Ed.), Rapid Excavation and Tunneling Conference Proceedings (pp. 905-926). New Orleans: Society for Mining, Metallurgy and Exploration. ISBN: 9780873352307.

[16] Unlutepe, A., Tellioglu, V., & Arioglu, B. (2009). Redicted and Observed Ground Deformations due to TBM Tunnel Excavations on the IZMIR Metro Project (Stage 1).  In P. Kocsonya (Ed.), ITA-AITES World Tunnel Congress: Safe Tunnelling for the City and Environment Conference Proceedings(pp. 234-240). Budapest, Hungary: Hungarian Tunnelling Association. ISBN: 9789630672399.

[17] Greenwood, J. D. (2003). Three Dimension Analysis of Surface Settlement in Soft Ground Tunneling. Master of Engineering Thesis, Massachusetts Institute of Technology (MIT), Department of Civil and Environmental Engineering. http://hdl.handle.net/1721.1/29558.

[18] Kasper, T., & Meschke, G. (2006). On the Influence of Face Pressure, Grouting Pressure and TBM Design in soft Ground Tunneling . Tunnelling and Underground Space Technology, 21(2), 160-171. http://dx.doi.org/10.1016/j.tust.2005.06.006.

[19] Lambrughi, A., Rodríguez, L. M., & Castellanza, R. (2012). Development and validation of a 3D Numerical Model for TBM–EPB Mechanized Excavations. Computers and Geotechnics Journal, 40, 97-113. http://dx.doi.org/10.1016/j.compgeo.2011.10.004.

[20] Nicolas, B., Branque, D., Subrin, D., Wong, H., & Humbert, E. (2012). Face Failure in Homogeneous and Stratified Soft Ground: Theoretical and Experimental Approaches on 1g EPBS Reduced Scale Model. Tunnelling and Underground Space Technology, 30, 25–37. http://dx.doi.org/10.1016/j.tust.2012.01.005.

[21] موسسه‌ی مهندسین مشاور ساحل

[1]     Guglielmetti, V., Grasso, P., Mahtab, A., & Xu, S. (2007). Mechanized Tunneling in Urban Areas: Design Methodology and Construction Control. (V. Guglielmetti, Ed.) London: Taylor and Francis e-Library. ISBN: 978-0-203-393851-5 (eBook).

[2]     Mohkam, M., & Wong, Y. W. (1989). Three Dimensional Stability Analysis of The Tunnel Face Under Fluid Pressure. Numerical Methods in Geomechanics (pp. 2271-2287). Rotterdam: A. A. Balkema.

[3]     Jancsecz, S., & Steiner, W. (1994). Face Support for a Large Mix-Shield in Heterogeneous Ground Conditions. Tunnelling '94: Seventh International Symposium Organized by the Institution of Mining and Metallurgy and the British Tunnelling Society (pp. 531-541). London: Chapman and Hall. ISBN: 9780412598609.

[4]     Broere, W. (1998). Face Stability Calculation for a Slurry Sheild in Hetrogeneous Soft Soils. In Nego, & Ferreira (Ed.), Proceedings of the World Tunnel Congress'98 on Tunnels and Metropolises (pp. 215-218). Sao Paolo, Brazil. Taylor & Francis. ISBN: 9789054109365.

[5]     Atkinson, J. H., & Potts, D. M. (1977). Subsidence above Shallow Tunnels in Soft Ground. Journal of the Geotechnical Engineering Division, 103(4), 307-325.

[6]     Attewell, P. B., & Woodman, J. P. (1982). Predicting the Dynamics of Ground Settlement and its Derivatives Caused by Tunneling in Soil. Ground Engineering, 15(8), 13-22.

[7]     Baligh,  M. (1985). Strain Path Method. Journal of Geotechnical Engineering, 111(9), 1108-1136. http://dx.doi.org/10.1061/(ASCE)0733-9410(1985)111:9(1108).

[8]     Chambon, P., & Corte, J. F. (1994). Shallow Tunnels in Cohesionless Soil: Stability of Tunnel Face. Journal of Geotechnical Engineering, 120(7), 1148–1165. http://dx.doi.org/10.1061/(ASCE)0733-9410(1994)120:7(1148).

[9]     Clough, G. W., Sweeney, B. P., & Finno, R. J. (1983). Measured Soil Response to EPB Shield Tunneling. Journal of Geotechnical Engineering, 109(2), 131-149. http://dx.doi.org/10.1061/(ASCE)0733-9410(1983)109:2(131).

[10] Leca, E. (1989). Analysis of NATM and Shield Tunneling in Soft Ground. Blacksburg: Doctoral Thesis, Virginia Institute and State University.

[11] Hwang, R. N., & Moh, Z. C. (1996). Pore Pressures Induced in Soft Ground due to Tunneling. In R. J. Mair, & R. N. Taylor (Ed.), Proceedings of the International Symposium on Geotechnical Aspects of Underground Construction in Soft Ground (pp. 695-700). Rotterdam: A. A. Balkema. ISBN: 9789054108566.

[12] Matsushita, Y., Iwasakl, Y., Hashimoto, T., & Imanishi, H. (1994). Behavior of Subway Tunnel Driven by Large Slurry Shield. Proceedings of the International Symposium on Geotechnical Aspects of Underground Construction in Soft Ground  (pp. 253-256). Rotterdam: A. A. Balkema.

[13] Chiorboli, M. A., & Marchesili, P. P. (1996). Analysis and Control of Subsidence due to Earth Pressure Shield Tunneling in Pass ante Ferroviario of Milano. In L. Ozdemr (Ed.), Proceedings of the International Conference on North American Tunneling'96 (pp. 97-106). Rotterdam: A. A. Balkema. ISBN: 9054108037.

[14] Suchatvee, S. (2002). Earth Pressure Balance (EPB) Shield Tunneling in Bangkok: Ground Response and Prediction of Surface Settlements Using Artificial Neural Networks. Doctoral Thesis, Massachusetts Institute of Technology (MIT), Department of Civil and Environmental Engineering. http://hdl.handle.net/1721.1/32222.

[15] Crow, M., & Holzhäuser, J. (2003). Performance of Four EPB-TBMs Above and Below the Groundwater Table on the ECIS Project, Los Angeles, CA, USA. In R. A. Robinson, & J. M. Marquardt (Ed.), Rapid Excavation and Tunneling Conference Proceedings (pp. 905-926). New Orleans: Society for Mining, Metallurgy and Exploration. ISBN: 9780873352307.

[16] Unlutepe, A., Tellioglu, V., & Arioglu, B. (2009). Redicted and Observed Ground Deformations due to TBM Tunnel Excavations on the IZMIR Metro Project (Stage 1).  In P. Kocsonya (Ed.), ITA-AITES World Tunnel Congress: Safe Tunnelling for the City and Environment Conference Proceedings(pp. 234-240). Budapest, Hungary: Hungarian Tunnelling Association. ISBN: 9789630672399.

[17] Greenwood, J. D. (2003). Three Dimension Analysis of Surface Settlement in Soft Ground Tunneling. Master of Engineering Thesis, Massachusetts Institute of Technology (MIT), Department of Civil and Environmental Engineering. http://hdl.handle.net/1721.1/29558.

[18] Kasper, T., & Meschke, G. (2006). On the Influence of Face Pressure, Grouting Pressure and TBM Design in soft Ground Tunneling . Tunnelling and Underground Space Technology, 21(2), 160-171. http://dx.doi.org/10.1016/j.tust.2005.06.006.

[19] Lambrughi, A., Rodríguez, L. M., & Castellanza, R. (2012). Development and validation of a 3D Numerical Model for TBM–EPB Mechanized Excavations. Computers and Geotechnics Journal, 40, 97-113. http://dx.doi.org/10.1016/j.compgeo.2011.10.004.

[20] Nicolas, B., Branque, D., Subrin, D., Wong, H., & Humbert, E. (2012). Face Failure in Homogeneous and Stratified Soft Ground: Theoretical and Experimental Approaches on 1g EPBS Reduced Scale Model. Tunnelling and Underground Space Technology, 30, 25–37. http://dx.doi.org/10.1016/j.tust.2012.01.005.

[21]موسسه‌ی مهندسین مشاور ساحل. (1389). گزارش مطالعات زمین‌شناسی مهندسی و ژئوتکنیک مسیر تونل خط 7 متروی تهران، قطعه‌ی شرقی- غربی. تهران، ایران.