تأثیر اندازه ذرات و درجه اشباع بر پتانسیل روانگرایی خاک ماسه‌ای

نوع مقاله : مقاله پژوهشی

نویسندگان

دانشکده فنی مهندسی، دانشگاه بین‌المللی امام خمینی (ره)، قزوین، ایران

چکیده

در سال‌های اخیر، بررسی خصوصیات مقاومتی خاک‌های غیراشباع با توجه به اهمیت مکش در این نوع خاک‌ها بیشتر محدود به خاک‌های ریزدانه چسبنده یا خاک‌های ماسه‌ای با تراکم بالا بوده است و تحقیقات کمی در مورد روانگرایی خاک‌های ماسه‌ای سست در حالت غیراشباع و تاثیر اندازه ذرات بر این رفتار انجام شده است. در این تحقیق سعی شده است تا با انجام یک سری آزمایش‌های سه محوری سیکلیک در شرایط زهکشی نشده بر روی سه نوع ماسه با دانه‌بندی‌های مختلف، تأثیر اندازه ذرات و درجه اشباع بر مقاومت روانگرایی خاک‌های ماسه‌ای سست غیراشباع بررسی گردد. نتایج تحقیق نشان می‌دهد که تغییرات فشار آب حفره‌ای و مقاومت روانگرایی در ماسه‌های مورد مطالعه تا حدود زیادی وابسته به اندازه ذرات و نسبت تخلخل بین دانه‌ای می‌باشد، به ‌طوری که ماسه 131 فیروزکوه به دلیل بیشتر بودن نسبت تخلخل بین دانه‌ای دارای کمترین مقاومت روانگرایی در حالت اشباع بین ماسه‌های مورد مطالعه می‌باشد. همچنین طبق نتایج به دست آمده، افزایش اندازه دانه‌های ماسه، مکش بافتی ایجاد شده در توده خاک به دلیل کاهش درجه اشباع را کاهش می‌دهد. افزایش تعداد سیکل‌های وقوع روانگرایی و در نتیجه آن مقاومت روانگرایی نمونه‌های ماسه مورد مطالعه در اثر کاهش درجه اشباع به خصوص در ماسه‌های دارای دانه‌های ریزتر از دیگر نتایج این تحقیق می‌باشد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

The effect of particle size and degree of saturation on liquefaction potential of sandy soil

نویسندگان [English]

  • Gholam Ali Jafarzadeh emenabadi
  • Seyed abolhasan Naeini
  • reza ziaie moayed
Imam Khomeini international university, Qazvin, Iran
چکیده [English]

In recent years, studies on strength characteristics of unsaturated soils due to the importance of suction in these types of soils have been more focused on cohesive fine-grained soils or compacted sandy soils and limited research on liquefaction of loose unsaturated sandy soils and the effect of particle size on this behavior have been done. In this paper, it has been aimed to investigate the effect of particle size and degree of saturation on liquefaction resistance of loose unsaturated sandy soils by performing a series of cyclic triaxial tests under undrained conditions on three types of sand with different grain size distributions. The results show that variation of pore water pressure and liquefaction resistance in studied sands are largely dependent on particle size and intergranular void ratio, so #131 Firoozkooh sand has the lowest liquefaction resistance in the saturated state due to its higher intergranular void ratio. Also, according to the obtained results, increasing the size of sand grains reduces the matric suction created in the soil mass due to a reduction in the degree of saturation. An increase in the number of cycles to liquefaction and, consequently the liquefaction resistance of the studied sand samples due to a decrease in saturation, especially in sands with finer grains, is another result of this study.

کلیدواژه‌ها [English]

  • Unsaturated soil
  • Particle size
  • Liquefaction potential
  • Cyclic triaxial test
  • Loose sand
[1] D.G. Fredlund, H. Rahardjo, Soil mechanics for unsaturated soils, A Wiley inter-science publication, (1993), New York.
[2] J. Xu, C. Liu, Liquefaction potential of unsaturated nevada sand at different initial conditions, Thesis for University of South Carolina, (2012).
[3] D.G. Fredlund, N.R. Morgenstern, R.A. Widger, The shear strength of unsaturated soils, Canadian Geotechnical Journal, 15(3) (1978) 313–321.
[4] Y.J. Cui, P. Delage, Yielding and plastic behaviour of an unsaturated compacted silt, Geotechnique, 46(2) (1996) 291-311.
[5] H. Toyota, K. Nakamura, N. Sakai, W. Sramoon, Mechanical Properties of Unsaturated Cohesive Soil in Consideration of Tensile Stress, Soils and Foundations, 43(2) (2003) 115-122.
[6] N. Nishimatsu, Y.S. Kim, T. Kodaka, S. Kimoto, triaxial compressive behavior of low saturated compacted silt under constant volume and unexhuasted air conditions, Proc . of 44th annual meeting of JGS, Japan, (2004) 831-832.
[7] F. Geiser, L. Laloui, L. Vulliet, Elasto-Plasticity of Unsaturated Soils: Laboratory Test Results on a Remoulded Silt, Soils and Foundations, 46(5) (2006) 545-556.
[8] T. Yabuki, F. Oka, S. Kimoto, Mechanical behavior of unsaturated silt under cyclic loading , Proc . of 42nd annual meeting of JGS, Japan, (2007) 771-772.
[9] T. Unno, M. Kazama, N. Sento, Liquefaction of Unsaturated Sand Considering the Pore Air Pressure and Volume Compressibility of the Soil Particle Skeleton, Soils and Foundations, 48(1) (2008) 87-99.
[10] T. Nishimura, J. Koseki, Attempt of cyclic triaxial test for an unsaturated silty soil under undrained condition, Proc . of 44th annual meeting of JGS, Japan, (2009) 641-642.
[11] S. Kimoto, F. Oka, J. Fukutani, T. Yabuki, K. Nakashima, Monotonic and Cyclic Behavior of Unsaturated Sandy Soil Under Drained and Fully Undrained Conditions, Soils and Foundations, 51(4) (2011) 663-681.
[12] Y. Tsukamoto, S. Kawabeb, Jo. Matsumoto, S. Hagiwara, Cyclic resistance of two unsaturated silty sands against soil liquefaction, Soils and Foundations, 54(6) (2014) 1094-1103.
[13] M. Vernay, M. Morvan, P. Breul, Influence of saturation degree and role of suction in unsaturated soils
behaviour: application to liquefaction, E3S Web of Conferences, 9 (2016) 1-6.
[14] Y. Tsukamoto, Degree of saturation affecting liquefaction resistance and undrained shear strength of silty sands, Soil Dynamics and Earthquake Engineering, https://doi.org/10.1016/j.soildyn.2018.04.041.
[15] L. Mele, J.T. Tian, S. Lirer, A. Flora, J. Koseki, Liquefaction resistance of unsaturated sands: experimental evidences and theoretical interpretation, Geotechnique, 69(6) (2019) 541-553.
[16] L. Mele, A. Flora, On the prediction of liquefaction resistance of unsaturated sands, Soil Dynamics and Earthquake Engineering, 125 (2019) 105689.
[17] K.H. Tran, S. Imanzadeh, S. Taibi, D.L. Dao, Liquefaction Behavior of Dense Sand Relating to the Degree of Saturation. In: Duc Long P., Dung N. (eds) Geotechnics for Sustainable Infrastructure Development, Lecture Notes in Civil Engineering, 62 (2020) 879-886.
[18] R. Ladd, Preparing Test Specimens Using Undercompaction, Geotechnical Testing Journal, 1(1) (1978) 16-23.
[19] K. Been, M.G. Jefferies, J. Hachey, The critical state of sands, Géotechnique, 41(3) (1991) 365-381.
[20] M. Okamura, K. Noguchi, Liquefaction resistances of unsaturated non-plastic silt, Soils and Foundations, 49(2) (2009) 221–229.
 [21] صادق زادگان، ر. "رفتار دینامیکی ماسه رس دار غیراشباع"، رساله دکتری، دانشگاه بین‌المللی امام خمینی (ره)، 1396.‌
[22] M. Okamura, Y. Soga, Effects Of Pore Fluid Compressibility On Liquefaction Resistance Of Partially Saturated Sand, Soils and Foundations, 46(5)  (2006) 695–700.
[23] H. Wang, J. Koseki, T. Sato, G. Chiaro, J.T. Tian, Effect of saturation on liquefaction resistance of iron ore fines and two sandy soils, Soils and Foundations, 56(4) (2016) 732–744.
[24] K. Ishihara, Liquefaction and Flow Failure during Earthquakes. Geotechnique, 43(3) (1993) 351-415.
[25] A. Shafiee, Cyclic Resistance, Pre and Post-Liquefaction Behavior of Dry Pluviated Silty Sands, Journal of Seismology and Earthquake Engineering, 8(3) (2006) 163-175.
[26] S.S. Kumar, A. Dey, A.M. Krishna, Liquefaction Potential Assessment of Brahmaputra Sand Based on Regular and Irregular Excitations Using Stress-Controlled Cyclic Triaxial Test, KSCE Journal of Civil Engineering, 24 (2020) 1070–1082.
[27] Y.B. Sonmezer, A. Akyuz, K. Kayabali, Investigation of the effect of grain size on liquefaction potential of sands, Geomechanics and Engineering, 20(3) (2020) 243-254.
[28] P. Chakrabortty, A. Das, Anil, Effect of Soil Grain Size on Liquefaction Strength of Sandy Soil. In: Latha Gali M., Raghuveer Rao P. (eds) Geohazards. Lecture Notes in Civil Engineering, 86 (2021) Springer, Singapore. https://doi.org/10.1007/978-981-15-6233-4_38.
[29] S. Yasuda, T. Kobayashi, Y. Fukushima, M. Kohari, T. Simazaki, Effect of degree of saturation on the liquefac-tion strength of Masa, Proc. 34th Jpn. Nat. Conf. Geotech. Engrg., (1999) 2071-2072.
[30] S. Huang, S.L. Barbour, D.G. Fredlund, Development and verification of a coefficient of permeability function for a deformable unsaturated soil, Canadian Geotechnical Journal, 35(3) (1998) 411–425.
[31] Y. Yoshimi, K. Tanaka, K. Tokimatsu, Liquefaction resistance of a partially saturated sand, Soils and Foundations, 29(3) (1989) 157-162.