بررسی پایداری جبهه‌ی حفاری تونل در محیط غیر اشباع با روش تحلیل حدی

نوذری, محمد امین; ملکی, محمد; یوسفی, بهنام

doi:10.22044/tuse.2014.444

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بررسی پایداری جبهه‌ی حفاری تونل در محیط غیر اشباع با روش تحلیل حدی

مقاله 2، دوره 3، شماره 1، بهار و تابستان 1393، صفحه 1-15 اصل مقاله (1773 K)

نوع مقاله: مقاله پژوهشی

شناسه دیجیتال (DOI): 10.22044/tuse.2014.444

نویسندگان

محمد امین نوذری¹؛ محمد ملکی

²؛ بهنام یوسفی³

¹دانشجوی دکترای تخصصی مکانیک خاک و پی؛ گروه مهندسی عمران؛ دانشگاه بین‌المللی امام خمینی

²دانشیار؛ گروه مهندسی عمران؛ دانشکده‌ی مهندسی؛ دانشگاه بوعلی سینا

³دانش‌آموخته کارشناسی‌ارشد عمران؛ دانشکده‌ی مهندسی؛ دانشگاه بوعلی سینا

چکیده

در این پژوهش در چارچوب روش تحلیل حدی، با بکارگیری یک مکانیسم گسیختگی سه‌بعدی با شکل اسپیرال لگاریتمی یکپارچه، پایداری جبهه‌ی حفاری تونل در محیط غیر‌ اشباع مورد بررسی قرار گرفته است. برای استخراج معادلات سینماتیک حاکم از یک معیار گسیختگی خاک غیر اشباع استفاده شده است. پس از وارد‌‌سازی پارامترهای غیر اشباع در معادلات حاکم و اکسترمم‌سازی، یک مجموعه تحلیل‌های پارامتری انجام شده است. بر اساس نتایج حاصل، مکش بافتی تاثیر بسزایی در پایداری جبهه‌ی حفاری تونل دارد. با افزایش مکش بافتی، فشار حدی لازم برای تامین پایداری جبهه کاهش یافته که این موضوع می‌تواند در موارد کاربردی، مد نظر مهندسین قرار گیرد. در انتها با شبیه‌سازی عددی مسئله، نتایج حاصل از روش‌های تحلیل حدی و عددی مقایسه شده است. بر اساس نتایج بدست آمده روش تحلیل حدی، هر ‌چند که روند گسیختگی برای هر دو روش شبیه است، فشار بیشتری را برای تامین پایداری جبهه‌ی حفاری پیش‌بینی می‌کند. بعلاوه اثرات مکش موجب تغییر در شکل گوه‌ی گسیختگی بخصوص در قسمت تاج می‌شود.

کلیدواژه ها

تحلیل حدی؛ گسیختگی اسپیرال؛ مکش بافتی؛ جبهه‌ی حفاری؛ خاک غیر اشباع

موضوعات

تحلیل پایداری؛ مدلسازی و تحلیل عددی؛ مکانیک خاک

عنوان مقاله [English]

Assessment of Tunnel Face Stability in Unsaturated Media Based on Limit Analysis Method

نویسندگان [English]

Mohammad Amin Nozari¹؛ mohammad maleki²؛ Behnam Yousefi³

¹PhD Candidate in Geotechnical Engineering; Imam Khomeini International University

²Associate Professor; Faculty of Engineering; Bu-Ali Sina University

³M.Sc. in Geotechnical Engineering; Faculty of Engineering; Bu-Ali Sina University

چکیده [English]

In this research, in the framework of limit analysis method with consideration of a 3-D continuous failure mechanism, stability of tunnel excavation face in unsaturated media was studied. Governing kinematic equations were adapted for unsaturated conditions with introducing unsaturated form of Mohr Coulomb failure criteria. Afterward, a set of parametric analyses, in different form of suction distribution and tunnel geometry were performed. Based on obtained results, matric suction and its distribution considerably influence tunnel face stability. Therefore, increase in matric suction leads to decrease in limit pressure exerted on tunnel face. In the final section of paper, finite element numerical analyses in the same conditions of material and geometry were executed. The results indicate that limit analysis predict a limit pressure more than finite element method.

Introduction
There are numerous studies in the literature concerning application of upper bond limit analysis for evaluation of tunnel face stability in soft ground. These works have used conventional soil mechanics theory. However, a large part of surface soils are in unsaturated condition. For many engineering problems especially in construction phase, the principle of unsaturated soil mechanics can be used. This can be more efficient for unloading problems such as Tunnelling or excavation. This approach describes the role of unsaturated parameters on tunnel face stability using limit analysis method.

Methodology and Approaches
Governing kinematic equations were firstly adapted to the unsaturated condition. Then, parametric study was performed using direct calculations on kinematic equations. In the final step of paper PLAXIS3D was used for numerical analyses.

Results and Conclusions

Increase of matric suction leads to more dissipated energy in sliding surfaces of failure mechanism (decrease in limit pressure).
Presence of matric suction in the analysis do not change the general form of failure mechanism.
Limit pressures exerted on tunnel face obtained from limit analysis method are less than those obtained from finite element methods.

The continuous spiral logarithmic form of limit analysis are confirmed qualitatively by finite element method.

کلیدواژه ها [English]

Limit analysis, Spiral failure, Matric suction, Tunnel face, Unsaturated soil

مراجع

[1] Chen, W. F. (2007). Limit Analysis and Soil Plasticity. J. Ross Publishing. ISBN-13: 978-1932159738.

[2] Kimura, T., & Mair, R. J. (1981). Centrifugal Testing of Model Tunnels in Soft Clay. Proceedings of the 10th International Conference on Soil Mechanics and Foundation Engineering (pp. 319-322). A. A. Balkema.

[3] Broms, B. B., & Bennermark, H. (1967). Stability of Clay at Vertical Openings. Journal of the Soil Mechanics and Foundations Division, 93(1), 71-94.

[4] Ellstein, A. R. (1986). Heading Failure of Lined Tunnels in Soft Soils. Tunnels and Tunnelling, 18(6), 51-54. http://dx.doi.org/10.1016/0148-9062(86)92603-3.

[5] Soubra, A. H. (2000). Three-Dimensional Face Stability Analysis of Shallow Circular Tunnels. International Conference on Geotechnical and Geological Engineering (pp. 1-6). Technomic. ISBN: 1587160676.

[6] Leca, E., & Dormieux, L. (1990). Upper and Lower Bound Solutions for The Face Stability of Shallow Circular Tunnels in Frictional Material. Geotechnique, 40(4). 581-606. http://dx.doi.org/10.1680/geot.1990.40.4.581.

[7] Lyamin, A. V., & Sloan, S. W. (2002). Upper Bound Limit Analysis Using Linear Finite Elements and Nonlinear Programming. International Journal for Numerical and Analytical Methods in Geomechanics, 26(2), 181-216. http://dx.doi.org/10.1002/nag.198.

[8] Vermeer, P. A, Ruse, N., & Marcher, T. (2002). Tunnel Heading Stability in Drained Ground. FELSBAU, 20(6), 8-18. http://www.ilf.com/Tunnel Heading Stability in Drained Ground.pdf.

[9] Vermeer, P. A., & Ruse, N. (2001). On the Stability of The Tunnel Excavation Front. Proceeding of First MIT Conference on Computational Fluid and Solid Mechanics (pp. 521-523). Elsevier Science Ltd. ISBN: 0080439446.

[10] Li, Y., Emeriault, F., Kastner, R., & Zhang, Z. X. (2009). Stability Analysis of Large Slurry Shield-Driven Tunnel in Soft Clay. Tunnelling and Underground Space Technology, 24(4), 472-481. http://dx.doi.org/10.1016/j.tust.2008.10.007.

[11] Anagnostou, G., & Kovari, K. (1994). The Face Stability of Slurry-Shield-Driven Tunnels. Tunnelling and Underground Space Technology, 9(2), 165-174. http://dx.doi.org/10.1016/0886-7798(94)90028-0.

[12] Horn, M. K., & Adams, J. A. S. (1966). Computer-Derived Geochemical Balances and Element Abundances. Geochimica et Cosmochimica Acta, 30(3), 279-297. http://dx.doi.org/10.1016/0016-7037(66)90003-2.

[13] Jancsecz, S., & Steiner, W. (1994). Face Support for a Large Mix-Shield in Heterogeneous Ground Conditions. Tunnelling'94, 531-550. http://dx.doi.org/10.1007/978-1-4615-2646-9_32.

[14] Broere, W. (1998). Face Stability Calculation for a Slurry Shield in Heterogeneous Soft Soils. Proceedings of the World Tunnel Congress'98 on Tunnels and Metropolises (pp. 215-218). A. A. Balkema. ISBN: 9789054109365.

[15] Klar, A., Osman, A. S., & Bolton, M. (2007). 2D and 3D Upper Bound Solutions for Tunnel Excavation Using Elastic Flow Fields. International Journal for Numerical and Analytical Methods in Geomechanics, 31(12): 1367-1374. http://dx.doi.org/10.1002/nag.597.

[16] Davis, E. H., Gunn, M. J., Mair, R. J., & Seneviratne, H. N. (1980). The Stability of Shallow Tunnels and Underground Openings in Cohesive Material. Geotechnique, 30(4), 397-416. http://dx.doi.org/10.1680/geot.1980.30.4.397.

[17] Osman, A. S., Mair, R. J., & Bolton, M. D. (2006). On The Kinematics of 2D Tunnel Collapse in Undrained Clay. Geotechnique, 56(9), 585-595. http://dx.doi.org/10.1680/geot.2006.56.9.585.

[18] 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).

[19] Subrin, D., & Wong, H. (2002). Tunnel Face Stability in Frictional Material: A New 3D Failure Mechanism. Comptes Rendus Mecanique, 330(7), 513-519. http://dx.doi.org/10.1016/S1631-0721(02)01491-2.

[20] Augarde, C. E., Lyamin, A. V., & Sloan, S. W. (2003). Stability of an Undrained Plane Strain Heading Revisited. Computers and Geotechnics, 30(5), 419-430. http://dx.doi.org/10.1016/S0266-352X(03)00009-0.

[21] Mollon, G., Dias, D., & Soubra, A. H. (2010). Face Stability Analysis of Circular Tunnels Driven by a Pressurized Shield. Journal of Geotechnical and Geoenvironmental Engineering, 136(1), 215-229. http://dx.doi.org/10.1061/(ASCE)GT.1943-5606.0000194.

[22] Yamamoto, K., Lyamin, A. V., Wilson, D. W., Sloan, S. W., & Abbo, A. J. (2011). Stability of a Circular Tunnel in Cohesive-Frictional Soil Subjected to Surcharge Loading. Computers and Geotechnics, 38(4), 504-514. http://dx.doi.org/10.1016/j.compgeo.2011.02.014.

[23] Fredlund, D. G., & Morgenstern, N. R. (1977). Stress State Variables for Unsaturated Soils. Journal of the Geotechnical Engineering Division, 103(5), 447-466. http://www.soilvision.com/ Stress State Variables for Unsaturated Soils.pdf.

[24] Zhang, L. L., Fredlund, D. G., Fredlund, M. D., & Wilson, G. W. (2014). Modeling the Unsaturated Soil Zone in Slope Stability Analysis. Canadian Geotechnical Journal, 51(12), 1384-1398. http://dx.doi.org/10.1139/cgj-2013-0394.

[25] Calo, E., Sako, K., Kitamura, R., & Tabata, M. (2012). Slope Stability Analysis with Change in Apparent Cohesion and Seepage. Proceeding of 5th Asia-Pacific Conference on Unsaturated Soils (pp. 588-593). Bangkok: Geotechnical Engineering Research and Development Center.ISBN: 978-1-62276-264-4.

[26] Bishop, A. W. (1959). The principle of effective stress. Teknisk Ukeblad I Samarbeide Med Teknik, 106(39), 859-863. http://geotekhne.com.co/EstructurasPDF/PrincipioEsfuerzosEfectivos.pdf.

[27] Fredlund, D. G., Morgenstern, N. R., & Widger, R. A. (1978). The Shear Strength of Unsaturated Soil. Canadian Geotechnical Journal, 15(3), 313-321. http://dx.doi.org/10.1139/t78-029.

[28] Sheng, D., Gens, A., Fredlund, D. G., & Sloan, S. W. (2008). Unsaturated soils: From Constitutive Modelling to Numerical Algorithms. Computers and Geotechnics, 35(6), 810-824. http://dx.doi.org/10.1016/j.compgeo.2008.08.011.

[29] Coussy, O. (2007). Revisiting the Constitutive Equations of Unsaturated Porous Solids Using a Lagrangian Saturation Concept. International Journal for Numerical and Analytical Methods in Geomechanics, 31(15), 1675-1694. http://dx.doi.org/10.1002/nag.613.

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