مطالعه عددی خاکریزهای متکی بر شمع‌های پیچی و بتنی تحت بارگذاری ترافیکی راه‌آهن

نوع مقاله : مقاله پژوهشی

نویسندگان

• محمد امین مشایخی ¹
• محمدرضا خانمحمدی ²

¹ دانشکده مهنسی عمران، دانشگاه صنعتی اصفهان

² دانشکده مهندسی عمران، دانشگاه صنعتی اصفهان

10.22067/jfcei.2023.80622.1209

چکیده

امروزه استفاده از المان‌های سازه‌ای مانند شمع‌ها، به عنوان یک راه‌حل مؤثر در بهبود عملکرد کلی یک سیستم خاکریزی به لحاظ پایداری و کنترل نشست در نظر گرفته می‌شوند. در سال‌های اخیر استفاده از شمع‌های پیچی به دلیل عملکرد مناسب تحت بار فشاری و کششی، نصب سریع و آسان شمع و حذف مشکلات بتن‌ریزی مورد توجه قرار گرفته است. این مقاله یک بررسی عددی از مقایسه عملکرد خاکریزهای متکی بر شمع‌های پیچی و بتنی ساخته شده بر روی خاک نرم، ارائه می‌دهد. برای این منظور مدل‌های المان محدود سه بعدی به‌طور جداگانه از خاکریزهای متکی بر شمع‌های پیچی و بتنی در حالی که طول و قطر شفت شمع‌های آن‌ها یکسان است، در نرم‌افزار آباکوس توسعه داده می‌شوند. نتایج مدل‌سازی ‌های عددی با مشاهدات میدانی و اندازه‌گیری‌های آزمایشگاهی دیگر پژوهشگران اعتبارسنحی می‌شوند. نتایج نشان می‌دهد استفاده از شمع‌های پیچی در مقایسه با شمع‌های بتنی، باعث کاهش قابل قبول نشست در خاکریز و خاک نرم پی خواهد شد، و حرکات جانبی خاکریز را کنترل می‌کند. همچنین توزیع نیروی محوری در شمع حاکی از آن است که شمع پیچی ظرفیت باربری بیشتری نسبت به شمع بتنی دارد و شمع‌ها به صورت اصطکاکی رفتار می‌کنند. حضور کلاهک شمع، باعث کنترل قابل قبول نشست‌ها در سیستم خاکریز متکی بر شمع می‌شود و ظرفیت باربری بیشتری در شمع بسیج خواهد شد. همچنین اضافه کردن پره به بدنه شمع در فواصل مختلف، تأثیر چشمگیری در بهبود عملکرد سیستم خاکریزهای متکی بر شمع نمی‌گذارد و حتی ممکن است باعث افزایش نشست و پایین آمدن مکانیزم انتقال بار شود.

کلیدواژه‌ها

• نشست‌های کلی و تفاضلی
• خاکریزهای متکی بر شمع
• شمع‌های پیچی
• ظرفیت باربری
• مدل‌سازی عددی

---

عنوان مقاله [English]

Numerical Investigation of Concrete and Helical Pile-supported Embankments Under Railway Traffic Loading

نویسندگان [English]

• Mohammad Amin Mashayekhi ¹
• Mohammadreza Khanmohammadi ²

¹ Department of Civil Engineering, Isfahan University of Technology

² Department of Civil Engineering, Isfahan University of Technology

چکیده [English]

The use of structural elements such as piles are considered as an effective solution in improving the overall performance of an embankment system in terms of stability and settlement control. In recent years using helical piles has been considered due to their proper performance. This research presents a numerical investigation to compare the performance of embankments rested on concrete and helical piles. A 3D finite element models are developed separately in ABAQUS software for embankments based on helical and concrete piles while the length and diameter of their pile shafts are the same. The model was validated via comparing the obtained numerical results with the field and laboratory measurements (observation). The results show that the helical piles have significantly reduced the settlement in the embankments and the soft foundation soil and controlled lateral embankment displacement. Also, the distribution of axial force along the embedment depth of the pile indicates that the helical pile has higher bearing capacity than the concrete pile and behaves frictionally. The presence of the cap on the helical pile was also examined and the results show that it causes adequate control of the settlement in the embankment system and increases the bearing capacity of the piles. In addition, adding the blade to the pile body at different distances does not have a significant effect on improving the performance of the pile-supported embankment system while it could lead to embankment settlement and lower load transmission.

کلیدواژه‌ها [English]

• Overall and differential settlement
• Embankments based on pile
• Helical piles
• Bearing Capacity
• Numerical modeling

مراجع

[1] J. Han and M. Gabr, "Numerical analysis of geosynthetic-reinforced and pile-supported earth platforms over soft soil," geotechnical geoenvironmental engineering, vol. 128, no. 1, pp. 44-53, 2002. https://doi.org/10.1061/(ASCE)1090-0241(2002)128:1(44)

[2] T. A. Pham and D. Dias, "3D numerical study of the performance of geosynthetic-reinforced and pile-supported embankments," Soils and Foundations, vol. 61, no. 5, pp. 1319-1342, 2021. https://doi.org/10.1016/j.sandf.2021.07.002

[3] N. K. Meena, S. Nimbalkar, B. Fatahi, and G. Yang, "Effects of soil arching on behavior of pile-supported railway embankment: 2D FEM approach," Computers and Geotechnics, vol. 123, pp. 103601, 2020. https://doi.org/10.1016/j.compgeo.2020.103601

[4] J. T. Wu, X. Ye, J. Li, and G. W. Li, "Field and numerical studies on the performance of high embankment built on soft soil reinforced with PHC piles," Computers and Geotechnics, vol. 107, pp. 1-13, 2019. https://doi.org/10.1016/j.compgeo.2018.11.019

[5] A. Bhasi and K. Rajagopal, “Numerical study of basal reinforced embankments supported on floating/end bearing piles considering pile–soil interaction,” Geotextiles and Geomembranes, vol. 43, no. 6, pp. 524-536, 2015. https://doi.org/10.1016/j.geotexmem.2015.05.003

[6] Y. Jiang, J. Han, and G. Zheng, "Numerical analysis of a pile–slab-supported railway embankment," Acta Geotechnica, vol. 9, no. 3, pp. 499-511, 2014. https://doi.org/10.1007/s11440-013-0285-9

[7] L. Briançon and B. Simon, "Performance of Pile-Supported Embankment over Soft Soil: Full-Scale Experiment," Journal of Geotechnical and Geoenvironmental Engineering, vol. 138, no. 4, pp. 551-561, 2012. https://doi.org/10.1061/(ASCE)GT.1943-5606.0000561

[8] R. P. Chen, Z. Z. Xu, Y. M. Chen, D. S. Ling, and B. Zhu, "Field Tests on Pile-Supported Embankments over Soft Ground," Journal of Geotechnical and Geoenvironmental Engineering, vol. 136, no. 6, pp. 777-785, 2010. https://doi.org/10.1061/(ASCE)GT.1943-5606.0000295

[9] G. Spagnoli and C. de Hollanda Cavalcanti Tsuha, "A review on the behavior of helical piles as a potential offshore foundation system," Marine Georesources & Geotechnology, vol. 38, no. 9, pp. 1013-1036, 2020. https://doi.org/10.1080/1064119X.2020.1729905

[10] M. Alwalan and A. Alnuaim, "Axial Loading Effect on the Behavior of Large Helical Pile Groups in Sandy Soil," Arabian Journal for Science and Engineering, no. 4, 2022. https://doi.org/10.1007/s13369-021-06422-9

[11] H. A. Perko, Helical piles: a practical guide to design and installation. John Wiley & Sons, 2009. [E-book]

[12] M. J. Nowkandeh and A. J. Choobbasti, "Numerical study of single helical piles and helical pile groups under compressive loading in cohesive and cohesionless soils," Bulletin of Engineering Geology and the Environment, vol. 80, no. 5, pp. 4001-4023, 2021. https://doi.org/10.1007/s10064-021-02158-w

[13] Z. H. Elsherbiny and M. H. El Naggar, "Axial compressive capacity of helical piles from field tests and numerical study," Canadian Geotechnical Journal, vol. 50, no. 12, 2013. https://doi.org/10.1139/cgj-2012-0487

[14] P. P. Kumar, S. Patra, S. Haldar, M. J. Brown, J. A. Knappett, and Y. U. Sharif, "3D numerical analysis of screw pile subjected to axial compressive and lateral load," in Indian Geotechnical Conference (IGC 2021), 2021. https://doi.org/10.1007/978-981-19-6998-0_8

[15] F. Azizi, Applied Analyses in Geotechnics: CRC Press. 1999.[E-book]

[16] M. Khanmohammadi and K. Fakharian, "Evaluation of performance of piled-raft foundations on soft clay: A case study," Geomechanics and Engineering, vol. 14, no. 1, pp. 43-50, 2018. https://doi.org/10.12989/gae.2018.14.1.043

[17] K. Fakharian and M. Khanmohammadi, "Evaluation of the effect of geometric characteristics of a piled-raft on its behavior on soft clay under drained conditions," Sharif Civil Engineering Journal, vol. 29, no. 2, pp. 71-76, 2013.

[18] G. Lazorenko, A. Kasprzhitskii, A. Kukharskii, A. Kochur, and V. Yavna, "Failure analysis of widened railway embankment with different reinforcing measures under heavy axle loads: A comparative FEM study," Transportation Engineering, vol. 2, pp. 100028, 2020.

https://doi.org/10.1016/j.treng.2020.100028

[19] M. Esmaeili, B. Naderi, H. K. Neyestanaki, and A. Khodaverdian, "Investigating the effect of geogrid on stabilization of high railway embankments," Soils and Foundations, vol. 58, no. 2, pp. 319-332, 2018. https://doi.org/10.1016/j.sandf.2018.02.005

[20] Technical and general specifications of railway infrastructure, No 279. Tehran: Management and Planning Organization, 2004 (in Persian)

[21] S. W. Abusharar, J.-J. Zheng, B.-G. Chen, and J.-H. Yin, "A simplified method for analysis of a piled embankment reinforced with geosynthetics," Geotextiles and Geomembranes, vol. 27, no. 1, pp. 39-52, 2009. https://doi.org/10.1016/j.geotexmem.2008.05.002

 

.