Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 32726
Using Micropiles to Improve the Anzali's Saturated Loose Silty Sand

Authors: S. A. Naeini, M. Hamidzadeh


Today, with the daily advancement of geotechnical engineering on soil improvement and modification of the physical properties and shear strength of soil, it is now possible to construct structures with high-volume and high service load on loose sandy soils. One of such methods is using micropiles, which are mostly used to control asymmetrical subsidence, increase bearing capacity, and prevent soil liquefaction. This study examined the improvement of Anzali's saturated loose silty sand using 192 micropiles with a length of 8 meters and diameter of 75 mm. Bandar-e Anzali is one of Iran's coastal populated cities which are located in a high-seismicity region. The effects of the insertion of micropiles on prevention of liquefaction and improvement of subsidence were examined through comparison of the results of Standard Penetration Test (SPT) and Plate Load Test (PLT) before and after implementation of the micropiles. The results show that the SPT values and the ultimate bearing capacity of silty sand increased after the implementation of the micropiles. Therefore, the installation of micropiles increases the strength of silty sand improving the resistance of soil against liquefaction.

Keywords: Soil improvement, silty sand, micropiles, SPT, PLT, strength.

Digital Object Identifier (DOI):

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1238


[1] Balkema, A.A., (1997), Hand book on liquefaction Remediation of Reclaimed land, Japan Port and Harbour Research Institute.
[2] Rahimi, A., jafarian, Y., Numerical Study of the Effect of Micropiles Group on Soil Liquefaction Potential, 10th International Congress on Civil Engineering, University of Tabriz, Iran, 2015.
[3] Cernica, J. N., Geotechnical Engineering: Soil Mechanics, 1995.
[4] Jefferies, M., Been, K., Soil Liquefaction: A critical state approach, 2006.
[5] Seed, H. B., and Idriss, I. M. (1971). "Simplified procedure for evaluating soil liquefaction potential." J. Soil Mechanics and Foundations Div., ASCE 97(SM9), 1249–273.
[6] Seed, H. B., and Idriss, I. M. (1982). Ground Motions and Soil Liquefaction during Earthquakes, Earthquake Engineering Research Institute, Oakland, CA, 134 pp.
[7] Youd, T. L., Idriss, I. M., Andrus, R. D., Arango, I., Castro, G., Christian, J. T., Dobry, R., Finn, W. D. L., Harder, L. F., Hynes, M. E., Ishihara, K., Koester, J. P., Liao, S. S. C., Marcuson, W. F., Martin, G. R., Mitchell, J. K., Moriwaki, Y., Power, M. S., Robert son, P. K., Seed, R. B., and Stokoe, K. H. (2001). Liquefaction resistance of soils: summary report from the 1996 NCEER and 1998 NCEER/NSF workshops on evaluation of liquefaction resistance of soils, J. Geotechnical and Geoenvironmental Eng., ASCE 127 (10), 817–33.
[8] Idriss, I. M., and Boulanger, R. W. (2006). Semi-empirical procedures for evaluating liquefaction potential during earthquakes, J. Soil Dynamics and Earthquake Eng. 26, 115–30.
[9] S. Nemat-Nasser, A. Shokooh, (1979), A unified approach to densification and liquefaction of cohesionless sand in cyclic shearing, Canadian Geotechnical Journal, 1979, 16(4): 659-678.
[10] Day, R.W., Geotechnical Earthquake Engineering Handbook, 2002.
[11] Towhata, I., & Ishihara, K. E. N. J. (1985). Shear work and pore water pressure in undrained shear. Soils and foundations, 25(3), 73-84.
[12] Liang, L. (1995). Development of an energy method for evaluating the liquefaction potential of a soil deposit (Doctoral dissertation, Case Western Reserve University).
[13] Jafarian, Y., Towhata, I., Baziar, M. H., Noorzad, A., & Bahmanpour, A. (2012). Strain energy based evaluation of liquefaction and residual pore water pressure in sands using cyclic torsional shear experiments. Soil Dynamics and Earthquake Engineering, 35, 13-28.
[14] Armour, T., Groneck, P., Keeley, J., Sharma,S., FHWA-SA-97-070 - Micropile Design and Construction Guidelines – Implementation manual: Federal Highway Administration – US Department of Transportation; 2005.
[15] Abdollahi, K., Mortezaei, A., A new expression for determining the bending stiffness of circular micropile groups, Soil Dynamics and Earthquake Engineering 77, pp 58–70, 2015.
[16] Takashi, Y., Yoshinori, N., Yoshinori,O., Efficiency of micro pile for seismic retrofit of foundation system. In: Proceedings of the twelfth world conference on earthquake engineering, Auckland, New Zealand; 2000.
[17] Sun, S., Zhu, B., Wang, J., Design method for stabilization of earth slopes with micropiles, Soils and Foundations 2013; 53 (4) 487–497.
[18] Ortega, J. M., Albaladejo, A., Pastor, J. L., Sanchez, I., Climent, M.A., Influence of using slag cement on the microstructure and durability related properties of cement grouts for micropiles, Volume 38, pp 84–93, 2012.
[19] Ghorbani, H. Hasanzadeh shooiili, E. Ghamari, J. Medzviecka, Comprehensive three-dimensional finite element analysis, parametric study and sensitivity analysis on the seismic performance of soil–micropile superstructure interaction, V 58, pp 21–36, 2014.
[20] Veludo, J., Jlio, E.N.B.S., Dias-da-Costa, D., Compressive strength of micropile-to-grout connections, V 26, Issue 1, pp 172–179, 2012.
[21] Elzoghby, E., Performance of footing with single side micro-piles adjacent to slopes, V 53, Issue 4, pp 903–910, 2014.
[22] Kagawa, T., (1992), “Effect of liquefaction on lateral pile response”, ASCE.Geotech Spec Pub, Piles Under Dynamics Loads, Vol 34, pp.207-223.
[23] Klar, A., Baker, R., Frydman, S., (2003), “Seismic soil–pile interaction in liquefiable soil”, Soil Dynamics and Earthquake Engineering, Vol 24, pp. 551-564.
[24] Kagawa, T., Minowa, C., Abe, A., Oda, S., (1995), “Shaking-table tests on and analyses of piles in liquefying sands”, Earthquake Geotechnical Engineering Proceedings of the First International Conference, ISTokyo, pp. 699-704.
[25] Sakajo, S., Chai, J. C., Nakajima, K., Maeda, M., (1995), “Effect of group pile on liquefaction resistance of sandy ground”, Proc., First Conf. on Earthquake Geotechnical Engineering, IS-Tokyo, pp. 755-760.
[26] Klar, A., Frydman, A., Baker, R., (2004), “Seismic analysis of infinite pile groups in liquefiable soil”, Soil Dynamics and Earthquake Engineering, Vol 24, pp. 565-575.
[27] Annual Book of ASTM Standards (ASTM), 2000.
[28] Micropile Design and Construction, Reference Manual. U.S. Department of Transportation Federal Highway Administration, Publication No. FHWA NHI-05-039, December 2005.