Performance of Hollow Bar Micropiles under Monotonic and Cyclic Lateral Loads
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Volume 141, Issue 5
Abstract
Hollow bar micropiles are becoming a popular option for foundation retrofitting because of their fast installation and effectiveness as both a foundation system and ground improvement at the same time. This paper presents a field study and numerical investigation of the lateral behavior of single hollow bar micropiles embedded in stiff silty clay deposits. Two monotonic and six cyclic lateral load tests were conducted on four micropiles, and the results were used to calibrate/verify a numerical model that was then used in a numerical investigation. The observed load-displacement curves demonstrated that the micropile behavior was flexible and was governed by the properties of soil along a depth equal to 10 times the pile diameter. The parametric study suggested that hollow bar micropiles can carry moderate lateral loads with proper reinforcement configurations and pile head fixity condition. During cyclic loading, the micropile head stiffness degraded initially as the number of load cycles increased. However, the stiffness reached a constant value after a specific number of cycles at the same load amplitude and at different cyclic load amplitudes.
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Acknowledgments
The authors would like to acknowledge the kind support provided by Williams Form Hardware for funding and supplying the steel bars and drilling bits for the project; EBS Engineering and Construction Limited, for installing the micropiles and help setting the reaction frame; and BASF for providing the grout at no cost.
References
Abd Elaziz, A. Y., and El Naggar, M. H. (2012). “Axial behaviour of hollow bar micropiles under monotonic and cyclic loading.” Geotech. Test. J., 35(2), 249–260.
Abd Elaziz, A. Y., and El Naggar, M. H. (2014a). “Geotechnical capacity of hollow bar micropiles in cohesive soils.” Can. Geotech. J., 51(10), 1123–1138.
Abd Elaziz, A. Y., and El Naggar, M. H. (2014b). “Group behaviour of hollow bar micropiles in cohesive soils.” Can. Geotech. J., 51(10), 1139–1150.
Anderson, J. B., Townsend, F. C., and Grajales, B. (2003). “Case history evaluation of laterally loaded piles.” J. Geotech. Geoenviron. Eng., 187–196.
ASTM. (2007). “Standard test methods for deep foundations under static lateral load.” D3966-07, West Conshohocken, PA.
Bierschwale, M. W., Coyle, H. M., and Bartoskewitz, R. E. (1981). “Field tests and new design procedure for laterally loaded drilled shafts in clay.”, Texas Transportation Institute, Texas A&M Univ., College Station, TX, 116.
Chen, Y.-J., and Lee, Y.-H. (2010). “Evaluation of lateral interpretation criteria for drilled shaft capacity.” J. Geotech. Geoenviron. Eng., 1124–1136.
Duncan, J. M., Evans, L. T., Jr., and Ooi, P. S. K. (1994). “Lateral load analysis of single piles and drilled shafts.” ASCE J. Geotech. Eng., 1018–1033.
FHWA NHI (Federal Highway Administration-National Highway Institute) (2005). “Micropile design and construction—Reference manual.”, U.S. Dept. of Transportation, McLean, VA, 436.
Idriss, I. M., Dobry, R., and Singh, R. D. (1978). “Nonlinear behaviour of soft clays during cyclic loading.” J Geotech. Eng., 104, (GT12), 1427–1447.
Isenhower, W. M., and Wang, S.-T. (2011). Technical manual for LPILE, Version 6, Ensoft, 214.
Juran, I., Benslimane, A., and Hanna, S. (2007). “Engineering analysis of dynamic behaviour of micropiles systems.” J. Transp. Res. Board, 1772(1), 91–106.
Matlock, H. (1970). “Correlations for design of laterally loaded piles in soft clay.” Proc., 2nd Offshore Technology Conf., Vol. 1, OTC 1204, Huston, 577–594.
McNulty, J. F. (1956). “Thrust loading on piles.” J. Soil Mech. Found. Div., 82(SM2), 1–25.
Poulos, H. G., and Davis, E. H. (1980). Pile foundations analysis and design, Wiley, New York, 397.
Pyke, R. (1984). Panel discussion, laterally loaded deep foundation (STP 835), ASTM, Philadelphia, 239–243.
Reese, L. C., and Welch, R. C. (1975). “Lateral loading of deep foundations in stiff clay.” J. Soil Mech. Found. Div., 101(GT7), 633–649.
Richards, T. D., and Rothbauer, M. J. (2004). “Lateral loads on pin piles (micropiles).” Drilled shafts, micropiling, deep mixing, remedial methods, and specialty foundation systems, Vol. 124, ASCE, Orlando, FL, 158–174.
Sivrikaya, O., and Togrol, E. (2006). “Determination of undrained strength of fine-grained soils by means of SPT and its applications in Turkey.” Eng. Geol., 86(1), 52–69.
Thomson, P., Leew, B., Zakeri, A., Becker, D., Bunce, C., and Dittrich, P. (2007). “Axial compression, axial tension and lateral load response of pre-production micropiles for the CPR Mile 62.4 Nipigon subdivision bridge.” Proc., 8th Int. Workshop on Micropile, Toronto.
Walker, J. N., and Cox, E. H. (1966). “Design of pier foundations for lateral loads.” Trans. Am. Soc. Agric. Eng., 9(3), 417–420.
Williams Form Engineering Crop. (2011). Ground anchored system, Vol. 109, Belmont, MI, 76.
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Published In
Journal of Geotechnical and Geoenvironmental Engineering
Volume 141 • Issue 5 • May 2015
Copyright
© 2015 American Society of Civil Engineers.
History
Received: Jan 8, 2014
Accepted: Dec 1, 2014
Published online: Jan 21, 2015
Published in print: May 1, 2015
Discussion open until: Jun 21, 2015
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