Comparison and Improvement of the Existing Cone Penetration Test Results: Shear Wave Velocity Correlations for Hungarian Soils

Authors: Ákos Wolf, Richard P. Ray

Abstract:

Due to the introduction of Eurocode 8, the structural design for seismic and dynamic effects has become more significant in Hungary. This has emphasized the need for more effort to describe the behavior of structures under these conditions. Soil conditions have a significant effect on the response of structures by modifying the stiffness and damping of the soil-structural system and by modifying the seismic action as it reaches the ground surface. Shear modulus (G) and shear wave velocity (v_s), which are often measured in the field, are the fundamental dynamic soil properties for foundation vibration problems, liquefaction potential and earthquake site response analysis. There are several laboratory and in-situ measurement techniques to evaluate dynamic soil properties, but unfortunately, they are often too expensive for general design practice. However, a significant number of correlations have been proposed to determine shear wave velocity or shear modulus from Cone Penetration Tests (CPT), which are used more and more in geotechnical design practice in Hungary. This allows the designer to analyze and compare CPT and seismic test result in order to select the best correlation equations for Hungarian soils and to improve the recommendations for the Hungarian geologic conditions. Based on a literature review, as well as research experience in Hungary, the influence of various parameters on the accuracy of results will be shown. This study can serve as a basis for selecting and modifying correlation equations for Hungarian soils. Test data are taken from seven locations in Hungary with similar geologic conditions. The shear wave velocity values were measured by seismic CPT. Several factors are analyzed including soil type, behavior index, measurement depth, geologic age etc. for their effect on the accuracy of predictions. The final results show an improved prediction method for Hungarian soils

Keywords: CPT correlation, dynamic soil properties, seismic CPT, shear wave velocity.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1130445

References:

[1] J. Schneider, A. McGillivray and P. Mayne, “Evaulation of SCPTU intra-correlations at sand sites in the Lower Mississippi River valley, USA” in Proceedings, 2th International Conference on Geophysical and Geotechnical Site Characterization (ISC’2), Rotterdamm, Millpress, pp. 1003-1010, 2004
[2] R.F. Obrzud, “On the use of the Hardening Soil Small Strain model in geotechnical practice, in Numerics in Geotechnics and Structures, Elmepress International, Lausanne, pp. 15-32, 2010
[3] G. Baldi, R. Bellotti, V. Ghionna, M. Jamiolkowski and L. Presti, “Modulus of sands from CPTs and DMTs” in Proceedings 12th International Conference on Soil Mechanics and Foundation Engineering, Vol. 1 pp. 165-170, Rio de Janeiro, Balkema, Rotterdam, 1989.
[4] P. Robertson, C. Woeller, and W. Finn, “Seismic cone penetration test for evaluating liquefaction potential”. Canadian Geotechnical Journal, Vol 29, pp. 686-695, 1992
[5] P.W. Mayne and J.G. Rix, “Correlations between shear wave velocity and cone tip resistance in natural clays,” Soils and Foundations, JSSMFE, Vol 35(2), pp 107-110, 1995.
[6] Y. Hegazy and P. Mayne, “Statistical correlations between vs and cone penetration data for different soil types” Proceedings, International Symposium on Cone Penetration Testing, CPT ’95, Linkoping, Sweden, Swedish Geotechnical Society, pp. 173-178, 1995
[7] C. Madiai and G. Simoni, “Shear wave velocity-penetration resistance correlation for Holocene and Pleistocene soils of an area in central Italy” Proceedings, 2th International Conference on Geophysical and Geotechnical Site Characterization (ISC’2), Rotterdamm, Millpress, pp. 1687-1694, 2004.
[8] R.D. Andrus, N.P. Mohanan, P. Piratheepan B.S. Ellis and T. L. Holzer, “Predicting shear wave velocity from cone penetration resitance”, in Proceedings, 4th International Conference on Earthquake Geotechnical Engineering, Thessaloniki, Greece, Paper No. 1545, 2007
[9] L. Karl, W. Haegeman and G. Degrade, “Determination of the material damping ratio and the shear wave velocity with the Seismic Cone Penetration Test, Soil Dynamics and Earthquake Engineering, Vol 26. pp 1111-1126, 2006
[10] P.K. Robertson, “Interpretation of cone penetration tests - a unified approach. Canadian Geotechnical Journal, Vol 46. pp. 1337-1355. 2009
[11] L. Tonni and P. Simonini, “Shear wave velocity as function of cone penetration test measurements in sand and silt mixture”. Engineering Geology, Vol 163, pp. 55-67 2013.
[12] P.K. Robertson and C.E. Wride, “Evaulating cyclic liquefaction potential using the cone penetration test, Canadian Geotechnical Journal, Vol. 35. pp 442-459, 198
[13] P.K. Robertson, R.G. Campanella, D. Gillespie and A. Rice, “Seismic CPT to measure in situ shear wave velocity, in ASCE J. GED, Vol 112 (8), pp 791-803, 1986
[14] S.L. Kramer: Geotechnical Earthquake Engineering, Prentice Hall, Upper Saddle River, New Jersey, 1996.
[15] JJ.M. Brouwer: In-situ soil testing, 2007, online book: http://www.conepenetration.com/online-book/