2D nonlinear site response analysis of typical stiff and soft soil sites at shallow bedrock region with low to medium seismicity

Chandran, D and Anbazhagan, P (2020) 2D nonlinear site response analysis of typical stiff and soft soil sites at shallow bedrock region with low to medium seismicity. In: Journal of Applied Geophysics, 179 .

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Abstract

In this study, an attempt has been made to estimate 2D nonlinear seismic site response of a small scale basin on typical stiff and soft soil sites in Peninsular India (PI). Six survey sites were selected from three shallow bedrock regions such as Kalpakkam, Bangalore and Vizag for which subsurface profiles are generated at these locations using Multichannel Analysis of Surface Wave -2D (MASW-2D) method. The subsurface profiles generated are classified as stiff and soft sites based on average 30 m shear wave velocity and further used for the 2D nonlinear site response analysis using the commercial program FLAC -2D. Thirteen intraplate ground motions from all around the world are selected for the site response analysis based on seismicity of the region. Results of the site response analysis were expressed in terms of short-period amplification factor (Fc) and long period amplification factor (Fs) for the intraplate shallow bedrock region. The results show that the Fc gives higher values than Fs in the case of stiff soil and it is showing a reverse trend in the case of soft soil. The trend of Fc is becoming more complex than that of the Fs especially in the case of stiff soil sites. Also, the 2D site response results were compared with conventional 1D nonlinear site response results using the program DEEPSOIL and aggravation factors were generated. Further, a parametric study has been carried out to quantitatively evaluate the effect of amplitude of ground motion on 2D site response analysis. Parametric study results show that subsurface heterogeneity is very sensitive to the low amplitude of input motion, especially in the case of stiff soil sites. © 2020 Elsevier B.V.

Item Type:	Journal Article
Publication:	Journal of Applied Geophysics
Publisher:	Elsevier B.V.
Additional Information:	Copy right for this article belongs to Elsevier B.V.
Keywords:	Seismic response; Shear flow; Shear waves; Soils; Surface waves; Wave propagation, Amplification factors; Multi-channel analysis of surface waves; Parametric study; Peninsular india; Shear wave velocity; Site response analysis; Subsurface heterogeneity; Subsurface profile, Nonlinear analysis, bedrock; ground motion; penetration test; response analysis; seismic method; seismic response; seismic velocity; seismicity; soft soil, India
Department/Centre:	Division of Mechanical Sciences > Civil Engineering
Date Deposited:	05 Nov 2021 05:43
Last Modified:	05 Nov 2021 05:43
URI:	http://eprints.iisc.ac.in/id/eprint/65704

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