NEEShub services are beginning to be phased out. Please begin using DesignSafe ( Please submit a support ticket ( if you need any assistance.


Support Options

Submit a Support Ticket


Characterization of Dynamic Soil-Pile Interaction by Random Vibration Methods: Experimental Design and Preliminary Results

Published on


Preliminary results are presented for full-scale vibration tests of piles using random vibration methods and a new servo-hydraulic inertial shaker testing system. Separate tests of vertical and coupled horizontal-rocking modes as well as hybrid multi-mode tests were performed on two steel HP 10x42 piles installed to a depth of 20 ft at a site containing soft clays. One pile was tested in the natural soil profile while the other had a cement deep soil mixed (CDSM) improved zone near the surface. Three excitation techniques were examined using a range of forcing intensities to determine the optimal testing configuration. The multi-modal vertical-eccentric test format was investigated as an efficient alternative to traditionally separate tests having vertical or horizontal forcing. Design of the experimental testing system is described, followed by a preliminary comparison of results from the various test configurations. Measurements indicate that the new excitation and instrumentation systems were successful in stimulating and capturing the broadband dynamic response of the soil-pile system for use in validating and calibrating advanced 3D computational continuum models.


The support of the NEES program of NSF through grant award CMMI-0936627 is gratefully acknowledged.


[1] Pak, R. Y. S., and Guzina, B. B. (1999), „Seismic soil-structure interaction analysis by direct boundary element methods.‟ Int. J. Solids Struct., 36, 4743–4766.
[2] Pak, R. Y. S., and Guzina, B. B. (2002). „Three-dimensional Green‟s functions for a multilayered half-space in displacement potentials.‟ J. Eng. Mech., 128(4), 449–461.
[3] Pak, R.Y.S. and Ashlock, J.C., „Method of Adaptive Gradient Elements for Computational Mechanics‟, Journal of Engineering Mechanics, 133 (1), 87-97, ASCE, 2007.
[4] Richart, Hall and Woods (1970), Vibrations of soils and foundations, Prentice-Hall, Englewood Cliffs, N. J.
[5] Ashlock, J.C. and Pak, R.Y.S. „Experimental Response of Piles in Sand under Compound Motion‟, Journal of Geotechnical and Geoenvironmental Engineering, 135 (6), 799-808, ASCE, 2009.
[6] Pak, R. Y. S. and Ashlock, J. C. (2000), „Fundamental dynamic behavior of foundations on sand‟, in R. Y. S. Pak and J. Yamamura, eds, „Soil Dynamics and Liquefaction 2000, GSP‟, number 107, ASCE, Denver, CO, USA, pp. 10–19
[7] Pak, R. Y. S., Ashlock, J. C., Abedzadeh, F. and Turner, N. (2006), „Dynamic hybrid-mode test of a pile on a centrifuge‟, in Ng, Zhang and Wang, eds, „Proc. 6th Int. Conf. Phys. Model. In Geotech.‟, Taylor and Francis Group, London.
[8] Pak, R. Y. S., Ashlock, J. C., Kurahashi, S. and Abedzadeh, F. (2008), „Parametric Gmax sounding of granular soils by vibration methods‟, Geotechnique, ICE 58(7), 571–580. URL:
[9] Pak, R.Y.S., Ashlock, J.C., Kurahashi, S. and Soudkhah, M., „Physical characteristics of dynamic vertical-horizontal-rocking response of surface foundations on cohesionless soils‟, Géotechnique, in publication, ICE.
[10] Ashlock, J.C. (2006), „Computational and Experimental Modeling of Dynamic Foundation Interactions With Sand‟, Ph.D. Thesis, University of Colorado at Boulder.
[11] Hushmand, B. (1983), Experimental Studies of Dynamic Response of Foundations, PhD thesis, California Institute of Technology, Pasadena, CA.
[12] Bendat, J. S. and Piersol, A. G. (1986), Random Data, Wiley-Interscience Publications, New York.
[13] Ashlock, J.C. and Phipps, J.N., “Experimental Multi-modal Foundation Vibrations and Comparison with Benchmark Half-space Solutions”, GeoFrontiers 2011, Advances in Geotechnical Engineering, Dallas, TX, Paper No. 1616, 10 pgs., March, 2011.

Cite this work

Researchers should cite this work as follows:

  • J.C. Ashlock and M.K. Fotouhi, “Characterization of Dynamic Soil-Pile Interaction by Random Vibration Methods: Experimental Design and Preliminary Results”, Proceedings of 2011 NSF Engineering Research and Innovation Conference, Atlanta, Georgia (CMMI Grantee Conference), 11 pages, January 2011.

  • Jeramy C Ashlock; Mohammad Fotouhi (2011), "Characterization of Dynamic Soil-Pile Interaction by Random Vibration Methods: Experimental Design and Preliminary Results ,"

    BibTex | EndNote