تحلیل عددی رفتار استاتیکی سد خاکی تحت تأثیر تغییر شیب هسته (مطالعه موردی: سد آزاد)

نوع مقاله : مقاله پژوهشی

نویسندگان

1 استادیار، گروه مهندسی عمران، دانشکده فنی و مهندسی، دانشگاه اراک، اراک، ایران.

2 دانش‌آموخته کارشناسی‌ ارشد ژئوتکنیک، گروه مهندسی عمران، دانشکده فنی و مهندسی، دانشگاه اراک، اراک، ایران.

چکیده

در طراحی سدهای خاکی، قائم یا مایل بودن هسته با توجه به ملاحظات فنی و اقتصادی، مزایا و معایب خاص خود را دارد. در هر یک از این گزینه‌ها، توجه به میزان نشت، تغییرشکل‌ها و تنش‌های ایجاد شده در بدنه و پی سد و نیز برقراری پایداری ضروری است. ضمن آنکه کنترل پدیده قوس‌زدگی ناشی از تنش‌ها و نشست‌های متفاوت در ترازها و مناطق مختلف که خود می‌تواند منجر به شکست هیدرولیکی سد گردد، بایستی بررسی شود. در این تحقیق ضمن تحلیل رفتار استاتیکی سد بلند "آزاد" در شرایط واقعی (با هسته رسی قائم) در نرم‌افزار GeoStudio، تحلیل تراوش، تنش- کرنش، قوس‌زدگی و پایداری دامنه‌های سد با زوایای مختلف هسته (صفر، پنج، 10، 15، 20 و 22 درجه نسبت به امتداد قائم) در دو فاز پایان ساخت و تراوش دائم نیز مورد بررسی و مقایسه قرار گرفت. نتایج نشان داد برای یک عمق مشخص، با افزایش زاویه تمایل هسته، دبی تراوش از بدنه و پی سد (به طور محسوس‌تر در زوایای بیش از 15 درجه) و جابجایی قائم خط مرکزی هسته افزایش یافت. همچنین با افزایش زاویه، متوسط ضریب اطمینان پایداری برای دامنه پایین‌دست سد به طور غیر محسوس افزایش، اما برای دامنه بالادست به ویژه برای زوایای بیش از 15 درجه کاهش بارز 6/22 درصدی داشت. روند افزایش تنش قائم کل خط مرکزی هسته با افزایش عمق نیز برای زوایای مختلف هسته، فاقد تغییرات قابل ملاحظه بود. در مورد قوس‌زدگی، به جز در محدوده ارتفاعی 3/0 ارتفاع از تاج، احتمال آن با افزایش زاویه تمایل هسته کم شد.

کلیدواژه‌ها

موضوعات

عنوان مقاله [English]

Numerical analysis of static behavior of embankment dam under changes in the core inclination (Case Study: Azad Dam)

نویسندگان [English]

  • Nazanin Shahkarami 1
  • Maryam Bayat 2
1 Assistant Professor, Department of Civil Engineering, Faculty of Engineering, Arak University, Arak, Iran.
2 M. Sc. Graduate of Geotechnics, Department of Civil Engineering, Faculty of Engineering, Arak University, Arak, Iran.
چکیده [English]

In the design of embankment dams, the vertical or inclination of the core has its own advantages and disadvantages according to technical and economic considerations. In each of these options, it is necessary to pay attention to the amount of seepage, deformations and stresses created in the body and foundation of the dam, as well as stability. In addition, the control of the arching caused by different stresses and subsidence in different levels and areas, which can lead to hydraulic failure of the dam, should also be considered. In this study, while analyzing the static behavior of the "Azad" dam in real condition (with a vertical core) in GeoStudio software, analysis of seepage, stress-strain, arching and slope stability with different core inclination (zero , five, 10, 15, 20 and 22 degrees relative to the vertical) at end of construction and steady-state seepage have also been studied and compared. The results showed that for a given depth, with increasing the angle of inclination of the core from the vertical position, the seepage through the dam body and foundation (especially for angles greater than 15 degrees) and the vertical displacement of the core central line increased. Also with increasing the angle of inclination, the average stability safety factor of the downstream slope of the dam increased imperceptibly but for the upstream slope especially for angles greater than 15 degrees, there was a significant decrease of 22.6 percent. The trend of increasing the total vertical stress along the central core line with increasing depth for different angles of the core did not change significantly. In the case of arching, except in the height range of 0.3 of the height of the crest, the probability decreased with increasing inclination angle of the core.

کلیدواژه‌ها [English]

  • Arching
  • Core inclination
  • Embankment dams
  • Static analysis

مراجع

  1. Aalimohammadi, S., Shahkarami, N., & Asadi H. (2021). Analysis of seepage in the conditions of increased reservoir capacity by raising the spillway level (Case study: Kamal-Saleh earth dam). Amirkabir Journal of Civil Engineering, 53(9) (2021). (In Persian)
  2. Al-Labban, S. (2018). Seepage and Stability Analysis of the Earth Dams under Drawdown Conditions by using the Finite Element Method, Ph.D. Thesis, University of Central Florida, US.
  3. Aminjavaheri, A., & Karam, M. (2014). Application of Shear Keys to Improve the Slope Stability of Earth Dams on Weak Alluvial Foundations. Journal of Soil Behavior and Geomechanics, ASCE, 642-650.
  4. Asakereh, A., & Ahang, M. (2017). Numerical Analysis of Arching Phenomenon at Core of Baft Zoned Embankment Dam, Kerman. Modares Civil Engineering Journal (M.C.E.J), 17(5). (In Persian)
  5. Calamak, M., Kilic, Y., & Yanmaz A.M. (2020). On the Stability of Moderate Height Berm-Type Earthen Dams: The Hancagiz Dam Example. Journal of Geotechnical and Geological Engineering, 38, 4169–4179. https://doi.org/10.1007/s10706-020-01286-6
  6. Fattah, M.Y., Omran, H.A., & Hassan, M.A. (2017). Flow and stability of Al-Wand earth dam during rapid drawdown of water in reservoir. Journal of Acta Montanistica Slovaca, 22(1).
  7. Iran Water and Power Resources Development Company, (2008). Geotechnical reports of Azad Rockfill Dam: Design of foundation and body of the dam. (In persian)
  8. Javaheri, A. R. (2009). Static and Dynamic Analysis of embankment Dams Using GEOSTUDIO, Iran, Elme Omran Press. (In Persian)
  9. karbor, A.H., & Soroush, A. (2011). Comparison of Behavior of an Embankment Dam with Inclined and Vertical Cores using Numerical Analysis. Civil Engineerng Infrastructures Journal, 44(5). (In Persian)
  10. Komasi, M., Mazaheri, A.R., & Beiranvand, B. (2020). Numerical analysis of the effect of arching Eyvashan dam in the first impounding period and its comparison with Instrumental results. Journal of Water and Soil Conservation, 26(6). DOI: 10.22069/jwsc.2019.14530.2969
  11. Mazaheri, A.R., Komasi, M., & Veisi, M. (2020). Numerical examination of embankment dams after construction and at the time of the first impounding-Case study is Doiraj dam in Ilam province. Journal of Civil and Environmental Engineering. (In Persian)
  12. Motamedi, M., & Hosseini, S.M.M. (2006). Arching and Optimum Mixture Percentage of Materials in Karkheh Dam, Iran.
  13. Najafzadeh, M. (2019). Projection of seepage and piezometric pressure in earth dams using soft computational models. Amirkabir Journal of Civil Engineering, 52(7). (In Persian)
  14. Nayebzadeh, R., & Mohammadi, M. (2011). The Effect of Impervious Clay Core Shape on the Stability of Embankment Dams. Journal of Geotechnical and Geological Engineering, 29, 627-635. DOI 10.1007/s10706-011-9395-z.
  15. Niroumand, H., Mirghasemi, A.A., & Pakzad, M. (2000). Monitoring of Karkheh Dam during Construction Using Instrumentation Data, 4th Conference on Dam Construction, Tehran, Iran.
  16. Rahimi, H. (2013). Embankment Dams, Fourth Edition, Tehran University Press,Iran.(In persian)
  17. Salmasi, F. Norouzi, R. Abraham, J., & et al. (2020). Effect of Inclined Clay Core on Embankment Dam Seepage and Stability through LEM and FEM. Journal of Geotechnical and Geological Engineering, 38, 6571-6586. https://doi.org/10.1007/s10706-020-01455-7
  18. Salmasi, F., & Hakimi Khansar, H. (2020). Simulation of behavior the Kabudval Dam during construction with 3D numerical modeling. Amirkabir Journal of Civil Engineering, 53(9). (In Persian)
  19. Sazzad, M. M., & Islam, M. M. (2019). A comprehensive study of different types of seepage control measures for earth dam using FEM. Journal of Civil and Construction Engineering, 5(1), 24-37.‏
  20. Shakouri, B., & Mohammadi, M. (2020). Evaluation of Penetration Depth for Cutoff Walls in the Core of Earth Dams. Journal of Geotechnical and Geological Engineering, 38, 151-167. https://doi.org/10.1007/s10706-019-01004-x
  21. Zahedi, P., & Aghazani, H. F. (2018). The effect of clay core specifications on the seepage behavior of an earthfill dam. 5th International Symposium on Dam Safety, Istanbul, Turkey.
مدیریت آب و آبیاری
دوره 12، شماره 3
شهریور 1401
صفحه 527-539

فایل ها

هم رسانی

ارجاع به این مقاله

آمار