پیوندهای مفید
آمار
| تعداد نشریات | 8 |
| تعداد شماره‌ها | 414 |
| تعداد مقالات | 5,478 |
| تعداد مشاهده مقاله | 6,010,619 |
| تعداد دریافت فایل اصل مقاله | 5,299,932 |
مدلسازی عددی سه بعدی پاسخ گروه شمع در برابر گسترش جانبی ناشی از روانگرایی | ||
| نشریه مهندسی عمران امیرکبیر | ||
| مقاله 3، دوره 52، شماره 5، مرداد 1399، صفحه 1061-1078 اصل مقاله (2.01 M) | ||
| نوع مقاله: مقاله پژوهشی | ||
| شناسه دیجیتال (DOI): 10.22060/ceej.2018.15184.5848 | ||
| نویسندگان | ||
| علی کاوند* 1؛ علی صادقی میبدی2 | ||
| 1دانشکده مهندسی عمران دانشگاه تهران | ||
| 2دانش آموخته کارشناسی ارشد سازه های دریایی، دانشکده مهندسی عمران، دانشگاه تهران، تهران، ایران | ||
| چکیده | ||
| در این مقاله رفتار گروه شمع در برابر گسترش جانبی ناشی از روانگرایی با استفاده از تحلیل المان محدود سه‌بعدی همبسته خاک-آب بررسی شده است. به منظور صحت سنجی مدل عددی، از نتایج یک مدل آزمایشگاهی بزرگ مقیاس میزلرزه 1g استفاده شده است. مدل عددی با دقت قابل قبولی پاسخ خاک در میدان آزاد شامل شتاب، فشار آب حفره‌ای اضافی و جابجایی و همچنین پاسخ گروه شمع شامل جابجایی و لنگر خمشی را شبیه‌سازی نموده است. نتایج نشان می‌دهد که روانگرایی در خاک، در لحظات ابتدایی لرزش در اعماق سطحی آغاز شده و با وقوع روانگرایی، دامنه شتاب خاک کاهش یافته است. بیشترین مقدار جابجایی جانبی خاک حین گسترش جانبی در فواصل دور از شمع‌ها رخ داده و جابجایی خاک در مجاورت شمع‌ها کاهش یافته است. تغییرات لنگر خمشی در شمع‌ها با عمق و به خصوص بیشینه لنگر خمشی در شمع‌ها نیز با دقت قابل قبولی شبیه‌سازی شده است. بیشینه لنگر خمشی منفی در نزدیکی کلاهک شمع و بیشینه لنگر خمشی مثبت در نزدیکی کف مدل رخ داده و مقدار بیشینه لنگر خمشی در شمع پایین دست گروه حدود 70 %بیشتر از بیشینه لنگر خمشی در شمع بالادست می‌باشد. نتایج مطالعه پارامتری نشان می‌دهد که با افزایش سختی خمشی شمع و همچنین کاهش تراکم ماسه، میزان جابجایی و لنگر خمشی در شمع کاهش می‌یابد. دامنه شتاب تحریک بیشترین تاثیر را بر پاسخ شمع داشته به گونه‌ای که با افزایش آن به 3/5 برابر مقدار اولیه، بیشینه لنگر خمشی در شمع3/6 برابر افزایش می‌یابد. | ||
| کلیدواژه‌ها | ||
| روانگرایی؛ گسترش جانبی؛ گروه شمع؛ مدلسازی عددی؛ OpenSees | ||
| موضوعات | ||
| پی های عمیق و ریز شمع ها؛ ژئو تکنیک لرزه ای | ||
| عنوان مقاله [English] | ||
| 3-Dimensional Numerical Modelling of Pile Group Response to Liquefaction-induced Lateral Spreading | ||
| نویسندگان [English] | ||
| Ali Kavand1؛ Ali Sadeghi Meibodi2 | ||
| 1School of Civil Engineering, University of Tehran | ||
| 2M.Sc. Student, School of Civil Engineering, College of Engineering, University of Tehran | ||
| چکیده [English] | ||
| In this paper, a 3D coupled soil-water finite element analysis is undertaken to simulate the behavior of a pile group subjected to liquefaction-induced lateral spreading. The results demonstrate that the numerical model can satisfactorily simulate the response of soil, including its accelerations, excess pore water pressures, and displacements as well as that of the piles including displacements and bending moments. Time histories of excess pore water pressure show that liquefaction in free field soil begins at the initial stages of shaking, and upon liquefaction, the amplitude of soil acceleration decreases. The maximum lateral displacement of the ground is observed in the regions far from the piles. On contrary, the extent of ground displacement decreases in areas close to the piles. The numerical model was able to predict the bending moment profiles in piles and particularly their maximum values. The maximum negative bending moments occur nearby the pile cap, while their maximum positive values are observed at the base of the piles. Moreover, the maximum bending moment in downslope piles of the group is about 70% greater than that in upslope one. The results of the parametric study show that with increasing either the flexural stiffness of piles or the relative density of the sand, the displacement of piles decreases while the bending moment in them increases. Also, it is revealed that the amplitude of input acceleration is the most influencing factor affecting the pile response as increasing it by a factor of 3.5 induces 3.6 times greater bending moments in piles. | ||
| کلیدواژه‌ها [English] | ||
| Liquefaction, Lateral Spreading, Pile Group, Numerical Modelling, OpenSees | ||
| مراجع | ||
|
[1] Hamada, M., Isoyama, R., Wakamatsu, K., “Liquefaction induced ground displacement and its related damage to lifeline facilities,” Soils and Foundations, January (Special Issue), 1996, pp. 81–97. [2] Bardet, J.P., Kapuskar, M., “Liquefaction sand boils in San Francisco during 1989 Loma Prieta earthquake,” Journal of Geotechnical and Geoenvironmental Engineering, 119(3), 1993, pp. 543-562. [3] Tokimatsu, K., Mizuno, H., Kakurai, M., “Building damage associated with geotechnical problems,” Soils and Foundations, January (Special Issue), 1996, pp..432-912 [4] Tokimatsu, K., Asaka, Y., “Effects of liquefactioninduced ground displacements on pile performance in the 1995 Hyogoken–Nambu earthquake,” Special Issue of Soils and Foundations, 1988, pp. 163-177. [5] Eberhard, M., Baldridge, S., Marshal, J., Monney, W., Rix, J., “The Mw 7.0 Haiti earthquake of January 12,” USGS/EERI Advance Reconnaissance Team, Team report, February 23, vol. 1.1, 2010. [6] Tokimatsu, K., Tamura, S., Suzuki, H., Katsumata, K., “Building damage associated with geotechnical problems in the 2011 Tohoku Pacific Earthquake,” Soils and Foundations, 52(5), 2012, pp. 956-974. [7] Newmark, N. M., “Effects of earthquakes on dams and embankments,” Geotechnique, vol. 2, 1965, pp. 139159. [8] Towhata, I., “Nature of lateral soil movement induced by earthquake liquefaction,” in Seminar on Seimic Design, 1991. [9] Toyota, H., Towhata, I., Imamura, S., Kudo. K., “Shaking table tests on flow dynamics in liquefied slope,” Soils Foundations, vol. 44, 2004, pp. 67-84. [10] He, L., Elgamal, A., Abdoun, T., “ LiquefactionInduced Lateral Load on Pile in a Medium Dr Sand Layer,” Journal of Earthquake Engineering, vol. 13, 2009, pp. 916-938. [11] Motamed, R., Sesov, V., Towhata, I., Anh, N. T.,“Experimental Modeling of Large Pile Groups in Sloping Ground Subjected To Liquefaction-Induced Lateral Flow: 1-G Shaking Table Tests,” Soils and Foundations, 2010, vol. 50, pp. 261-279. [12] Haeri, S. M., Kavand, A., Rahmani, I., Torabi, H., “ Response of a group of piles to liquefaction-induced lateral spreading by large scale shake table testing,” Soil Dynamics and Earthquake Engineering, vol. 38, 2012, pp. 25-45. [13] Kavand, A., Haeri, S. M., Rahmani, I., Ghalandarzadeh, A., Bakhshi, A., “Study of the behavior of pile groups during lateral spreading in medium dense sands by large scale shake table test,” International Journal of Civil Engineering, 12(3-B), 2014, pp. 186-203. [14] Abdoun, T., Dobry, R., O’Rourke, T., Goh, S.H., “Pile response to lateral spreads: centrifuge modeling,” Journal of Geotechnical and Geoenvironmental Engineering, 129(10), 2003, pp. 869-878. [15] Imamura, S., Hagiwara, T., Tsukamoto, Y., Ishihara, K., “Response of pile groups against seismically induced lateral flow in centrifuge model tests,” Soils and Foundations, 44(3), 2004, pp. 39–55. [16] Brandenberg, S., Boulanger, R., Kutter, B., Chang, D., “Behaviour of pile foundations in laterally spreading ground during centrifuge test,” Journal of Geotechnical and Geoenvironmental Engineering, 131(11), 2005, p.p 1378-1391. [17] Gonzalez, L., Abdoun, T., Dobry, R., “Effect of soil permeability on centrifuge modeling of pile response to lateral spreading,” Journal of Geotechnical and Geoenvironmental Engineering, 35(1), 2009, p.p 6273. [18] Cubrinovski, M., Uzouka, R., Sugita, H., Tokimatsu, K., “ Prediction of pile response to lateral spreading by 3-D soil-water coupled dynamic analysis: Shaking in the direction of ground flow,” Soil Dynamics and Earthquake Engineering, 28(6), 2007, p.p. 421-435. [19] Uzouka, R., Cubrinovski, M., Sugita, H., Sato, M., “ Prediction of pile response to lateral spreading by 3-D soil-water coupled dynamic analysis: Shaking in the direction perpendicular to ground flow,” Soil Dynamics and Earthquake Engineering, 28(6), 2008, pp. 436-452. [20] Cheng, Z., Jeremic, B., “Numerical Modeling and simulation of pile in liquefiable soil,” Soil Dynamics and Earthquake Engineering, vol. 29, 2009, pp. 14051416. [21] Manzari, M. T., Dafalias, Y. F., “A critical two-surface plasticity model for sands,” Geotchnique, 47(2), 1997, pp. 255-272. [22] Dafalias, Y. F., Manzari, M. T., “Simple plasticity sand model accounting for fabric change effects,” Journal of Engineering Mechanics, 130(6), 2004, pp. 622-634. [23] Rahmani, A., Pak, A., “Dynamic behavior of pile foundations under cyclic loading in liquefiable soils,” Computers and Geotechnics, vol. 40, 2012, pp. 114126. [24] Li, G., Motamed, R., “Finite element modelling of soilpile response subjected to liquefaction-indecued lateral spreading in a large-scale shake table experiment,” Soil Dynamics and Earthquake Engineering, vol. 92, 2017, pp. 573-584. [25] Haeri, S. M., Kavand, A., Asefzadeh, A., Rahmani, I., “Large scale 1-g shake table model test on the response of a stiff pile group to liquefaction induced lateral spreading,” Proceedings of the 18th International Conference on Soil Mechanics and Geotechnical Engineering, 2013, Paris. [26] Mazzoni, S., McKenna, F., Fenves, G. L., “Open system for earthquake engineering simulation,” Pacific Earthquake Engineering Research Center, Unversity of California, Berkeley, 2006. [27] McKenna, F., Scott, M., Fenves, G., “Nonlinear finite-element analysis software architecture using object composition,” Journal of Computational Civil Engineering, 24(1), 2010, pp. 95-107. [28] Biot, M., “Theory of propagation pf elastic waves in a fluid-saturated porous solid,” The Journal of the Acoustical Society of America, vol. 28, 1956, pp. 168.191 [29] Haeri, S. M., Kavand, A., Raisianzade, J., Padash, H., Rahmani, I., Bakhshi, A., “Observations from a large scale shake table test on a model of existing pile-supported marine structure subjected to liquefaction induced lateral spreading,” in Second European Conference on Earthquake Engineering and Seismology, 2014, Istanbul. [30] Elgamal, A., Yang, Z., Parra, E., “Computational modeling of cyclic mobility and post-liquefaction site response,” Soil Dynamics and Earthquake Engineering, vol. 22, 2002, pp. 259-271. [31] He, L., Ramirez, J., Lu, J., Tang, L., Elgamal, A., Tokimatsu, K., “Lateral spreading near deep foundations and influence of soil permeability,” Canadian Geotechnical Journal, 54(6), 2017, pp. 846861. [32] Bayat, M., and Ghalandarzadeh, A., “Stiffness degradation and damping ratios of sand-gravel mixtures under saturated state,” International Journal of Civil Engineering, 2017, https://doi.org/10.1007/ s40999-017-0274-8.
| ||
|
آمار تعداد مشاهده مقاله: 898 تعداد دریافت فایل اصل مقاله: 921 |
||