Considering the effect of loads and surrounding texture on steel pipeline in potable municipal water networks with Ansys Finite Element Model

Document Type : Original Article

Authors

1 MSc (Water Structure) of Soil & Water Department, Pnu University Of Sabzevar

2 Associate Professor, Water Engineering Department, Sari Agricultural Sciences & Natural Resources University;

3 MSc (hydraulic Structure) of Water Engineering Department, Ferdowsi University of Mashhad

Abstract

The effect of internal and external forces on the transmission and distribution networks of potable municipal water makes more problems in the Iran water and waste water Corporation. Therefore, analyzing loaded forces is very important. Pipe insertion in the trenches, the channel filler material tend to have subsidence because of its reload and the channel subsidence on its bed causes trenches and the soil column above the channel move downward compared to adjacent undisturbed soils.  The mentioned phenomena and its modeling are not considered along with many water pipeline designs. Thereafter, the current case study is presented. In order to evaluating this research, the data of flexible steel pipeline with large diameter is gathered from Mashhad Abfay company and its modeling is done with 5 atmospheres internal pressure in Ansys finite element software. The more credibility is satisfied with selecting the current elements of Ansy’s Plane 42 and Plane 82. The output results showed 8/5 mm mean subsidence in the pipe and also 5 cm in the asphalt surface. Amount of subsidence in the element Plane 42 was about 0/6 mm less than average. Subsidence process was similar in both elements and was in accordance with the assumptions. In one hand, Plane 82 element was found that due to damping by considering the characteristics and volume of soil, more efficient than other element in determining the substrate deformation behavior and around the tube and on the other hand, the flexible pipes are tolerant to deformation and its preventive force against to stress concentration is higher than rigid channels.

Keywords

References

  1. 1. بوستانی، آ.، ک. م. صابری و س. ر. خداشناس. 1389. ارزیابی و مدل‌سازی عددی خطوط انتقال آب در اثر بارگذاری‌های متداول شهری، مجموعه مقالات نهمین کنفرانس هیدرولیک ایران، دانشگاه تربیت مدرس، آبان 1389.

    1. 2.  بوستانی، آ.، گلمایی و ح. انصاری. 1389. مدل‌سازی نشست سازه‌های سطحی در اثر مجرای تحت فشار حامل جریان زیرسطحی توسط روش اجزا محدود، مجموعه مقالات پنجمین کنگره ملی مهندسی عمران، دانشگاه فردوسی مشهد، اردیبهشت 1389.

    3. توفیق، م. م. و س. ط. طباطبایی. 1383. پیش‌بینی نشست منطقه‌ای زمین به روش محاسبه برگشتی و تاثیر نشست بر شبکه فاضلاب، مجله تحقیقات مسکن و ساختمان، وزارت مسکن و شهرسازی، تهران، ص 58-44.

    4. گروه نویسندگان و کار گروه ارزیابی وزارت نیرو.، مهندسی خطوط لوله انتقال آب (منطبق بر ضوابط نشریه شماره 185 سازمان مدیریت و برنامه ریزی)، چاپ دوم، انتشارات دانشگاه تهران، 1383.

    1. 5.  مهین‌روستا، ر. و م. یعقوبی. 1387. بررسی پاسخ استاتیکی و دینامیکی مخازن نیمه مدفون با توجه به جنس خاک بستر، چهارمین کنگره ملی مهندسی عمران، دانشگاه تهران، اردیبهشت 1387.

    6. Barkahov, E. 2001. “Introduction to The Finite Element Method”., Riga Technical University.

    1. 7.  Brinkgreve, R.B.J. 2003. Plaxis V8.2 Reference manual., Delf University of Technology, Netherlands.
    2. 8.  Dongwei, S., D. Jianbo and Z. Yong. 2001. “Investigation of pressure in pipe subjected to axial-symmetric pulse loading”., International Journal of Impact Engineering, (25)-(523-536).
    3. 9.  Elachachi, S.M., D. Breysse and L. Houy. 2004. “Longitudinal variability of soils and structural response of sewer networks”., Computers and Geotechnics (31).

    10. Guarracino, F., A.C. Walker and A. Giordano. 2009. “Effects of boundary conditions on testing of pipes and finite element modeling”., International Journal of Pressure Vessels and Piping., 86, pp:196–206.

    11. Hyde, T.H., R. Lou and A.A. Becker. 2009. “Analysis of stresses in pipes indented by long external indentation & subsequent stress variation due to pressure fluctuations”., International Journal of Pressure Vessels and Piping, vol 86 ,pp 428–434.

    12. Lofgern, B.E. 1979. Changes in aquifer-system properties with ground water depletion., Proc International Conference on Evaluation and Prediction of Land Subsidence, Pensacola, American Society of Civil Engineers, pp: 26-46.

    13. Ozkan, I.F. and M. Mohareb. 2009. Moment resistance of steel pipes subjected to combined loads-International Journal of Pressure Vessels and Piping 86, pp: 252–264.

    14. Nowzartash, F. and M. Mohareb. 2004. “An elasto-plastic finite element for steel pipelines”., International Journal of Pressure Vessels and Piping, 81-919–930.

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