Effect of uncertainty in $V_{\mathrm{S}}{-}N$ correlations on seismic site response analysis

Journal of earth system science

Narayan Roy^1¹  Ravi S Jakka^2² 

[1] Department of Civil Engineering, Jadavpur University, Kolkata, India.^1;Department of Earthquake Engineering, IIT Roorkee, Roorkee, India.^2

关键词: Damping ratio;    ground response;    modulus reduction;    shear-wave velocity;    site amplification;    $V_{\mathrm{S}}–N$ correlations;   

DOI  :  

学科分类：天文学(综合)

来源: Indian Academy of Sciences

【 摘 要 】

This paper studies the reliability of the calculated shear-wave velocity $(V_{\mathrm{S}})$ from different available $V_{\mathrm{S}}$ and SPT-N correlations in terms of seismic site response analysis. In the present study, various $V_{\mathrm{S}}–N$ correlations developed for different regions around the globe have been used to calculate the bound of $V_{\mathrm{S}}$ variations with depth at three different sites in Kolkata city. This bound has later been used to generate the random $V_{\mathrm{S}}$ profiles using the Monte Carlo simulation. Equivalent linear site response analysis has been performed to study the response of those generated profiles under different input motion excitations. Strong-to-weak ground motion records have been used for this purpose. The amplification spectra of the generated $V_{\mathrm{S}}$ profiles using all soil types and specific soil-type $V_{\mathrm{S}}–N$ correlations show significant variations. The study also shows that the $V_{\mathrm{S}}–N$ correlation may result in quite different $V_{\mathrm{S},30}$ values and subsequently it may lead to the different site classes according to the NEHRP 2003 classification. So, the random choice of the $V_{\mathrm{S}}–N$ correlation, where the direct measurement of $V_{\mathrm{S}}$ is not available, may affect the outcome of seismic hazard analysis significantly. The study points out the need for accurate estimation of the $V_{\mathrm{S}}$ profile either from in-situ determination or using site-specific correlation.

【 授权许可】

CC BY