Static and Dynamic Analyses of Micropiles to Reinforce the High Railway Embankments on Loose Beds

Authors

1 Assistant Professor, School of Railway Engineering, Iran University of Science and Technology, 16846 Iran, Tehran, Narmak

2 M.Sc., School of Railway Engineering, Iran University of Science and Technology, 16846 Iran, Tehran, Narmak

Abstract

Construction of railway embankments on loose beds without using any methods of soil improvement (e.g. stone columns in silt and clay beds, deep soil mixing method, jet grouting and also using micropiles individually or in groups form) leads to  reduction of embankment slope gradient, which significantly increases the volume of soil operation. Generally, micropile as a reinforcing element with the main characteristics of improving the mechanical-physical properties of soil, is a proper methodology for the aim of improving loose earth with low bearing capacity and intensive settlement characteristics. This paper explores numerical models of non-reinforced and reinforced railway embankments (with the height of 10 to 25 m) rested on loose beds that simulated and analyzed by SLIDE software. It should be considered that in order to reinforce the embankments using different arrangements of micropiles. In addition, the non-reinforced and reinforced embankments were analyzed against different load combinations that consist of railway operational load, permanent weight of the rail line and intense earthquake load. It should be mentioned that LM71 standard load was used as operational load during the simulations. The main purpose of this paper is finding the optimum arrangement of micropiles to reinforce the high railway embankments on loose beds. Therefore, according numerical analyses procedure, it was resulted that the use of micropiles exactly between toe and 1/3 to 1/2 length of the embankment slope is the optimal way to reinforce the embankments on loose beds.

Keywords

References

[1] Esmaeili, M., Gharouni Nik, M., Khayyer, F. (2010), “Improvement the railway embankments with micropiles”. M.S. thesis, School of Railway Engineering of Iran University of Science and Technology, Tehran, pp. 50-100.
[2] FHWA, (2000). “Micropile design and construction guidelines”. Report No. FHWA-SA-97-070, United States Department of Transportation, pp. 31-200.
[3] Cantoni, R., Collotta, T., Ghionna, V.N., Moratti, P.V. (1989). “Design method for reticulated micropiles structures in sliding slopes”. Ground Engng, Elsevier Ltd., Vol. 22, No. 4, pp. 41-47.
[4] Haider, T.F., Byle, M.J., Horvath, R.E. (2004). “Dam stabilization with micropiles”. Proceedings of Sessions of Geo‐Denver 2000, ASCE, Denver, Colorado.
[5] Bruce, J., Ruel, M., Janes, M., Ansari, N. (2004). “Design and construction of a micropile wall to stabilize a railway embankment”. Proceedings of the 29th Annual Conference on Deep Foundations, Vancouver, British Columbia, Canada "Emerging Technologies", DFI, pp. 1-11.
[6] Wang, Z., Met, G., Cai, G., Yu, X. (2009). “Dynamic finite element analysis of micropile foundation in subgrade”. Proceedings of Selected Papers from the 2009 GeoHunan International Conference, ASCE, Changsha Hunan, China, pp. 139-144.
[7] Howe, W.K. (2010). “Micropiles for slope stabilization”. Proceedings of the 2010 Biennial Geotechnical Seminar, ASCE, Denver, Colorado.
[8] Azami, A., Charbonneau, K., Corkum, B., Sinnathurai, V. (2003). “SLIDE version 5.0 Tutorial Manual”. Rocscience Inc., Toronto, ON, Canada.
[9] Ehteshami, M., Esmaeil Pour, E., Esmaeili, A.M. (2004). “Earth works for railway lines general technical specifications, Manual No. 279”, Management and Planning Organization Office of Deputy for Technical Affaires of Iran, Tehran, pp. 6-12.
[10] UIC719-R, (1994). “Earthworks and track-bed layers for railway lines”. UIC719-R-Second Edition, International Union of Railways, pp. 85-100.
[11] Das, B.M. (2005), “Principles of geotechnical engineering”. The University of Texas at El Paso, pp. 50-150.
[12] Zakeri, J.A., Shahroudi, M.M. (2006). “Investigating the effect of increasing axial load on the railway subgrade”. M.S. thesis, School of Railway Engineering of Iran University of Science and Technology, Tehran, pp. 151-153.
[13] Pearlman, S.L., Campbell, B.D., Withiam, J.L. (1992). “Slope stabilization using insitu earth reinforcements”. Proceedings of the ASCE Specialty Conference on Stability and Performance of Slopes and Embankments-II, Berkeley, California.
[14] ACI 318, (2005). “Building code requirements for structural concrete and commentary”. ACI 318R-05, American Concrete Institute, Farmington Hills, pp. 438-450.

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History

  • Receive Date: 22 June 2013
  • Accept Date: 22 June 2013

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