تأثیر شرایط زهکشی بر رفتار مکانیکی ماسه شماره 161 فیروزکوه تحت آزمایش‌های سه‌محوری

نوع مقاله : مقاله کامل پژوهشی

نویسندگان

دانشکده مهندسی عمران، دانشگاه تبریز

10.22034/ceej.2025.69554.2458

چکیده

رفتار تنش- کرنش خاک‌ها نقش اساسی در تحلیل پایداری و پیش‌بینی نشست سازه‌های ژئوتکنیکی دارد و شرایط زهکشی در این میان اهمیت ویژه‌ای پیدا می‌کند. پس از رخداد زلزله، معمولاً شرایط کاملاً زهکشی‌شده یا زهکشی‌نشده در طبیعت حاکم نیست؛ زیرا خاک‌های دانه‌ای به‌دلیل نفوذپذیری بالا مستعد تغییرات حجمی بوده و اغلب از یک رفتار نسبتاً زهکشی‌شده پیروی می‌کنند. با وجود این، اثر چنین شرایطی هنوز در مطالعات ژئوتکنیکی به‌طور کامل درک نشده است. این پژوهش، به بررسی اثر مسیرهای کرنش برشی- حجمی کنترل‌شده بر رفتار مونوتونیک ماسه شماره 161 فیروزکوه پرداخته ‌است. بدین منظور، آزمایش‌های سه‌محوری فشاری و کششی اشباع در چهار حالت کاملاً زهکشی‌شده، زهکشی‌نشده و دو حالت نسبتاً زهکشی‌شده با نرخ کرنش حجمی انقباضی و انبساطی انجام شد. نتایج نشان داد که زاویه اصطکاک مؤثر بحرانی مستقل از شرایط زهکشی بوده و تقریباً ثابت باقی می‌ماند. با‌‌این‌حال، پاسخ فشار آب حفره‌ای و مقاومت برشی به‌شدت تحت تأثیر شرایط زهکشی قرار گرفت. در حالت زهکشی نسبی انقباضی، کاهش قابل توجه فشار آب حفره‌ای و بهبود سخت‌شوندگی کرنشی موجب دستیابی نمونه‌ها به بیشترین مقاومت برشی شد. در مقابل، مسیر زهکشی نسبی انبساطی با افزایش تخلخل و تجمع فشار آب حفره‌ای، افت چشمگیری در سختی و مقاومت ایجاد کرد؛ به‌ویژه در بارگذاری کششی که نمونه رفتاری کاملاً انقباضی و نزدیک به روانگرایی بروز داد. در مجموع، یافته‌ها نشان می‌دهند که کنترل زهکشی می‌تواند نقش کلیدی در بهبود پایداری شیب‌های ماسه‌ای ایفا کند.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Effect of Drainage Conditions on the Mechanical Behavior of Firoozkuh No. 161 Sand under Triaxial Tests

نویسندگان [English]

  • Vahid Abazari Oskouei
  • Masoud Hajialilue Bonab
Faculty of Civil Engineering, University of Tabriz, Tabriz, Iran
چکیده [English]

The investigation of soil stress–strain behavior plays a fundamental role in the stability analysis and settlement prediction of geotechnical structures. Among the influencing factors, drainage conditions are of particular importance; previous studies indicate that soil mechanical behavior following an earthquake cannot be fully represented by the two limiting cases of fully drained or undrained conditions. Instead, it predominantly occurs under partially drained conditions, resulting from the simultaneous changes in pore water pressure and soil volume. The present study was designed to investigate the effect of partial drainage on the monotonic behavior of Firoozkuh No. 161 sand through a series of triaxial compression and extension tests. For analysis, effective stress paths, stress–strain curves, and excess pore water pressure responses obtained under partially drained conditions were compared with those from fully drained and undrained cases. The findings indicate that partial drainage has a significant influence on the shear behavior of sand.

کلیدواژه‌ها [English]

  • Granular soil
  • Triaxial test
  • Partial drainage
  • Shear strength
  • Critical state
  • Stress path
Abazari Oskouei V, Maleki Tabrizi E, Hajialilue Bonab M, “An experimental study on triaxial compression tests considering coupled volumetric–shear strain paths”, The International Conference on Nature-Inspired Solutions for Built Environment, 2025. https://doi.org/10.26392/SSM.NlSE.24.052
Adamidis O, Madabhushi SPG, “Experimental investigation of drainage during earthquake-induced liquefaction”, Géotechnique, 2018, 68 (8), 655-665.
Ampadu SK, Tatsuoka F, “Effect of setting method on the behaviour of clays in triaxial compression from saturation to undrained shear”, Soils and Foundations, 1993, 33 (2), 14-34.
ASTM D5311, “Standard test method for load controlled cyclic triaxial strength of soil”, ASTM International, West Conshohocken, PA, 2011.
ASTM D2487, “Standard practice for classification of soils for engineering purposes (Unified Soil Classification System)”, ASTM International, West Conshohocken, PA, 2011.
ASTM D7181, “Standard test method for consolidated drained triaxial compression test for soils”, ASTM International, West Conshohocken, PA, 2011, 1-12.
Chen WB, Liu K, Feng WQ, Yin JH, “Partially drained cyclic behaviour of granular fill material in triaxial condition”, Soil Dynamics and Earthquake Engineering, 2020, 139, 106355.
Dai F, Lee CF, Wang S, Feng Y, “Stress-strain behaviour of a loosely compacted volcanic-derived soil and its significance to rainfall-induced fill slope failures”, Engineering Geology, 1999, 53 (3-4), 359-370.
Eliadorani AA, “The response of sands under partially drained states with emphasis on liquefaction”, Doctoral Dissertation, University of British Columbia, 2000.
Farahmand K, Lashkari A, Ghalandarzadeh A, “Firoozkuh sand: introduction of a benchmark for geomechanical studies”, Iranian Journal of Science and Technology, Transactions of Civil Engineering, 2016, 40 (2), 133-148.
Gananathan N, “Partially drained response of sands”, Doctoral dissertation, University of British Columbia, 2002.
Irani AE, Hajialilue-Bonab M, Assadi-Langroudi A, Tabrizi EM, “Pore-pressure-dependent performance of rocking foundations”, Soil Dynamics and Earthquake Engineering, 2024, 183, 108772. https://doi.org/10.1016/j.soildyn.2024.108772
Lashkari A, Falsafizadeh SR, Rahman MM, “Influence of linear coupling between volumetric and shear strains on instability and post-peak softening of sand in direct simple shear tests”, Acta Geotechnica, 2021, 16 (11), 3467-3488.
Lashkari A, Yaghtin MS, “Sand flow liquefaction instability under shear–volume coupled strain paths”, Géotechnique, 2018, 68 (11), 1002-1024. https://doi.org/10.1680/jgeot.17.P.164
Logeswaran P, “Behaviour of sands under simultaneous changes in volume and pore pressure”, Doctoral dissertation, Carleton University, 2005. https://doi.org/10.22215/etd/2005-07628
Maleki Tabrizi E, Dibazar AA, Hajialilue-Bonab M, Esmatkhah Irani A, Assadi-Langroudi A, “The partially drained behaviour of dense fibre-reinforced sands”, Sustainability, 2023, 15 (23), 16286. https://doi.org/10.3390/su152316286
Miura S, Toki S, “A sample preparation method and its effect on static and cyclic deformation-strength properties of sand”, Soils and Foundations, 1982, 22 (1), 61-77.
Roscoe KH, Schofield AN, Wroth AP, “On the yielding of soils”, Géotechnique, 1958, 8 (1), 22-53.
Salomon J, Patino-Ramirez F, O’Sullivan C, “Stress-dilatancy and micromechanics of sand under partially drained conditions”, Computers and Geotechnics, 2025, 183, 107200.
Sivathayalan S, Logeswaran P, “Behaviour of sands under generalized drainage boundary conditions”, Canadian Geotechnical Journal, 2007, 44 (2), 138-150. https://doi.org/10.1139/t06-110
Sivathayalan S, Logeswaran P, “Experimental assessment of the response of sands under shear-volume coupled deformation”, Canadian Geotechnical Journal, 2008, 45 (9), 1310-1323. https://doi.org/10.1139/T08-068
Tabrizi EM, Tohidvand HR, Hajialilue-Bonab M, Mousavi E, Ghassemi S, “An investigation on the strain accumulation of the lightly EICP-cemented sands under cyclic traffic loads”, Journal of Road Engineering, 2023, 3 (2), 203-217.
Tohidvand HR, Maleki Tabrizi E, Esmatkhah Irani A, Hajialilue-Bonab M, Farrin M, “Effects of the fiber reinforcement on the monotonic behavior of sands considering coupled volumetric–shear strain paths”, International Journal of Geosynthetics and Ground Engineering, 2023, 9 (4), 39. https://doi.org/10.1007/s40891-023-00462-x
Umehara Y, Zen K, Hamada K, “Evaluation of soil liquefaction potentials in partially drained conditions”, Soils and Foundations, 1985, 25 (2), 57-72. https://doi.org/10.3208/sandf1972.25.2_57
Vaid YP, Eliadorani A, “Instability and liquefaction of granular soils under undrained and partially drained states”, Canadian Geotechnical Journal, 1998, 35 (6), 1053-1062. https://doi.org/10.1139/t98-061
Vaid YP, Eliadorani A, “Undrained and drained (?) stress-strain response”, Canadian Geotechnical Journal, 2000, 37 (5), 1126-1130. https://doi.org/10.1139/t00-036
Yamamoto Y, Hyodo M, Orense RP, “Liquefaction resistance of sandy soils under partially drained condition”, Journal of Geotechnical and Geoenvironmental Engineering, 2009, 135 (8), 1032-1043. https://doi.org/10.1061/(ASCE)GT.1943-5606.0000051
Yoshimine M, Ishihara K, “Flow potential of sand during liquefaction”, Soils and Foundations, 1998, 38 (3), 189-198. https://doi.org/10.3208/sandf.38.3_189
Yoshimine M, Robertson PK, Wride CE, “Undrained shear strength of clean sands to trigger flow liquefaction: Reply”, Canadian Geotechnical Journal, 2001, 38 (3), 654-657. https://doi.org/10.1139/t00-114
Zhu J, Leung AK, Wang Y, “Partially drained uplift behaviour of plant roots in dilative soils”, Canadian Geotechnical Journal, 2023, 61 (3), 500-518. https://doi.org/10.1139/cgj-2023-0104
Zürn J, Mugele L, Stutz HH, “Novel experimental method for rate-independent triaxial tests under partial drainage condition”, Géotechnique Letters, 2024, 14 (3), 100-105. https://doi.org/10.1680/jgele.23.00120