Seasonal Variation of VS at Shallow Depth and Nonlinear Behavior of Soil Based on the ARGONET Vertical Array Data

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Published: Apr 30, 2024
DOI: https://doi.org/10.12681/ta.36945
Keywords:
shear-wave velocity, interferometry, soil response.
Zafeiria Roumelioti
Department of Geology, University of Patras
https://orcid.org/0000-0001-5038-3052
Fabrice Hollender
CEA DES, DIMP, DCET, SESN, Cadarache, 13108 Saint-Paul-lez-Durance, France / UGA, USMB, CNRS, IRD, UGE, ISTerre, 38000 Grenoble, France
https://orcid.org/0000-0003-1440-6389
Abstract

Ground acceleration time histories from earthquakes recorded by the ARGONET vertical array in Cephalonia, Greece, in the period from July 2016 to April 2022, are analyzed seeking evidence for nonlinear behavior of the shallow soil layers. Shear waves velocity, VS, between the shallowest sensor pair of the vertical array, i.e., within the top 5.6 m of the soil column, is derived for each earthquake record using the method of interferometry by deconvolution. The temporal variation of VS values is compared with indicators related to soil moisture and this leads to the identification of a clear difference in the level of the measured values between periods of intense rainfall and the dry summer months. Lower velocities, even lower than the level of VS during rainy periods (7-13% of the annual average), are obtained based on the strongest records of the analyzed sample. These low velocities are considered as indicators of nonlinear soil behavior, the threshold onset of which is difficult to determine without prior correction for the seasonal variation. The applied method can provide a detailed description of VS changes even during a single earthquake. Examples are provided on how nonlinear soil behavior may be manifested by a sudden VS value drop at the arrival of the strongest seismic phases.

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  • Earthquake Engineering
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References
Field, E.H., Johnson, P.A., Beresnev, I.A., Zeng, Y.: Nonlinear ground-motion amplification by sediments during the 1994 Northridge earthquake. Nature 390, 599–602(1997).
Lee, W.H.K., Shin, T.C., Kuo, K.W., Chen, K.C., Fu, C.F.: CWB free-field strong-motion data from the 21 September Chi-Chi, Taiwan, earthquake. Bull. Seism. Soc. Am.91, 1370–1376 (2001).
Rubinstein, J.L.: Nonlinear site response in medium magnitude earthquakes near Parkfield, California. Bull. Seism. Soc. Am. 101(1), 275-286 (2011).
Régnier, J., Cadet, H., Bonilla, L.F., Bertrand, E., Semblat, J.F.: Assessing nonlinear behavior of soils in seismic site response: statistical analysis on KiK-net strong-motion data. Bull. Seism. Soc. Am. 103(3), 1750-1770 (2013).
Chandra, J., Guéguen, Ph., Bonilla. L.F.: PGA-PGV/VS considered as a stress-strain proxy for predicting nonlinear soil response. Soil Dyn. Earthq. Eng. 85, 146-160 (2016).
Beresnev, I.A., Wen, K.L.: Nonlinear soil response – a reality. Bull. Seism. Soc. Am.86(6), 1964-1978 (1996).
Assimaki, D., Li, W., Steidl, J.H., Schmedes, J.: Quantifying nonlinearity susceptibility via site-response modeling uncertainty at three sites in the Los Angeles Basin. Bull.Seism. Soc. Am. 98(5), 2364-2390 (2008).
Theodoulidis, N., Hollender, F., Mariscal, A., Moiriat, D., Bard, P.-Y., Konidaris, A., Cushing, M., Konstantinidou, K., Roumelioti, Z.: The ARGONET (Greece) seismic observatory: An accelerometric vertical array and associated data. Seism. Res. Lett. 89(4),1555–1565 (2018).
Abrahamson, N.A.: Program on Technology Innovation: Effects of Spatial Incoherence on Seismic Ground Motions. EPRI, Palo Alto, California, (2007).
Mehta, K., Snieder, R., Graizer, V.: Downhole receiver function: A case study. Bull.Seism. Soc. Am. 97(5), 1396–1403 (2007).
Guéguen, Ph.: Predicting nonlinear site response using spectral acceleration VSPGV/VS30: A case history using the Volvi-Test site. Pure Appl. Geophys. 173(6),2047–2063 (2016).
Roumelioti, Z., Hollender, F., Guéguen, Ph.: Rainfall-induced variation of seismic waves velocity in soil and implications for soil response: what the ARGONET (Cephalonia, Greece) vertical array data reveal. Bull. Seism. Soc. Am. 110(2), 441-451 (2020).
Clayton, R.W., Wiggins, R.A.: Source shape estimation and deconvolution of teleseismic bodywaves. Geophys. J. Roy. Astron. Soc. 47, 151–177 (1976).
Wu, C.Q., Peng, Z.G., Ben-Zion, Y.: Refined thresholds for non-linear ground motion and temporal changes of site response associated with medium-size earthquakes. Geophys. J. Int. 182, 1567-1576 (2010).