Scientific Quarterly Journal of Iranian Association of Engineering Geology

Scientific Quarterly Journal of Iranian Association of Engineering Geology

Investigation of the effect of diameter, distance and angle of micropiles on the stability of slopes under Steady State Seepage

Document Type : Original Article

Authors
farhad pirmohammadi alishah 1
Mehdi Mohammad Rezaei 2
1 Department of Geology, Faculty of Sciences, Islamic Azad University, Shabestar Branch, Shabestar, Iran.
2 Assistant Professor, Department of Civil Engineering, Faculty of Engineering, Tasuj Branch, Islamic Azad University, Tasuj, Iran
Abstract
In urban areas, based on the space constraints, one of the most important issues in the stabilization of slopes is to choose a suitable method for the design of the slope by considering technical and executive problems. Despite the proper design and execution of slopes, a variety of the natural and the artificial factors in a particular period of time may greatly affect their stability. In this study, the investigate the effect of microclimates on the stability of gables under the effect of steady state seepage, seepage analysis was performed using Seep / W software and finite element method, assuming unsaturated saturation flow and in steady state flow. Also, using Slope / W software, slope stability in different conditions including distance, diameter and angle of micropile has been investigated and the sensitivity of the results for permeability and soil resistance parameter has been investigated. The innovation of the present study is using the special parts which eliminates the common assumptions of the limit equilibrium method. Therefore, it is expected that this method will has less error in determining the reliability coefficient. According to the results, it was observed that seepage in the slope, diameter and distances of small piles have a great effect on the stability of the slope, which can be varied according to different conditions. As the distance between the micropiles increases, the slope reliability coefficient with different micropiles diameters becomes closer to the slope reliability coefficient without micropiles and somehow converges to this reliability coefficient.
Keywords
Sloping
Micropile
Seepage
Stability
Friction angle coefficient
اسدی، م.، حشمتی ع،ا. 1390. مقایسه ضریب اطمینان شیروانی خاکی مسلح به روش‌های مختلف، ششمین کنگره ملی مهندسی عمران.
حشمتی رفسنجانی، ع.ا.،قدمگاهی، ع. 1393. تحلیل پایداری شیروانی‌ها به روش اجزاء محدود، کنفرانس ملی ژئوتکنیک.
عسگری, ش.، شهیر، ه. ۱۳۹۵. روشی تحلیلی برای آنالیز پایدارسازی شیب‌های خاکی با ریزشمع‌ها، چهارمین کنگره بین المللی عمران ، معماری و توسعه شهری، تهران، دبیرخانه دایمی کنفرانس، دانشگاه شهید بهشتی.
عسگری، ش.، شهیر، ه. ۱۳۹۵. استفاده از رویکرد تعادل حدی اصلاح شده جهت تحلیل و طراحی ریزشمع‌های پایدار کننده شیب‌ها، چهارمین کنفرانس ملی پژوهش‌های کاربردی در مهندسی عمران، معماری و مدیریت شهری، تهران، دانشگاه صنعتی خواجه نصیرالدین طوسی.
Abd Elaziz, A.Y. 2012. Performance of hollow bar micropiles under axial and lateral loads in cohesive soils. Ph.D. thesis, Department of Civil and Environmental Engineering, Western University, London,
Cheng Y.M., Lau C.K. 2008. Slope Stability Analysis and Stabilization- New methods and insight",Taylor and Francis, London and New York, 260 p.
Geo-slop Company. 2004. Seepage Modeling with SEEP/W, User’s Guide, version, Geo-slope, Calgary, Alberta, Canada.
Guo, W. D. 2013.  Pu-based solutions for slope stabilizing piles. International Journal of Geomechanics, 13 (3), 292-310.
Huang Y.H. 1983. Stability analysis of earth slopes, van nostrand reihold Co., New York.
Kim M., Freeman M., FitzPatrick B.T., Nevius D.B., Plaut R.H. and Filz G.M. 2004. Use of an apron to stabilize geomembrane tubes for fighting floods", Geotextiles & Geomembrane, Vol. 239:22.
Kourkoulis, R., Gelagoti, F., Anastasopoulos, I. and Gazetas, G. 2012. Hybrid Method for Analysis and Design of Slope Stabilizing Piles, Journal Of Geotechnical and Geoenvironmental Engineereing ASCE.
Loehr J. E., Bowders J. J. and Salim. 2000. Slope stabilization using recycled plastic pins, constructability, Final Report Missouri DOT RDT .07.
Loehr J.E., Bowders J.J. 2007. Slope Stabilization Using Recycled Plastic Pins – Phase III, Missouri Department of Transportation Report, 290 p.
Moharrami A, Hassanzadeh Y, Salmasi F, Moradi Gh, Moharrami Gh. 2014. Performance of the horizontal drains in upstream shell of earth dams on the upstream slope stability during rapid drawdown conditions. Arabian Journal of Geoscience 7:1957-1964.
Sadek, M. and Shahrour, I. 2006. Influence of the head and tip connection on the seismic performance of micropiles. Soil Dyn. Earth. Eng. 26: 461–468.
SivakumarBabu G.L. and Singh P.S. 2010. 2D Numerical Simulations of Soil Nail Walls,” Geotechnical and Geological Engineering, 28(4), pp. 299-.903.
Sommers L., Loehr J.E. and Bowders J.J. 2000. Construction Methods for Slope Stabilization with Recycled Plastic Pins, Proceedings of Mid-Continent Transportation Symposium, Iowa, USA, pp. 254-258.
Turan, A., El Naggar, M. H. and Hinchberger, S. 2007. Seismic performance of a single micro-pile in layered soil. 8th International Workshop on Micropiles.
Vandamme J and Zou Q. 2013. Investigation of slope instability induced by seepage and erosion by a particle method. Computers and Geotechnics  48: 9-20.
Wei, W. and Y. Cheng. 2010. Soil nailed slope by strength reduction and limit equilibrium methods.Computers and Geotechnics.
Xu Y.F., Huang J. 2000. Case Study on Earth Reinforcement Using Soilbags, Proceedings of the 4th Asian Regional Conference on Geosynthetics, Shanghai, China, pp. 597-602.
Scientific Quarterly Journal of Iranian Association of Engineering Geology
Volume 15, Issue 1
Spring 2022
Pages 9-28

  • Receive Date 26 July 2020
  • Revise Date 12 September 2021
  • Accept Date 13 October 2021