Empirical Correlations with Standard Penetration Test (SPT)-N for Estimating Shear Wave Velocity Applicable to Any Region

Abstract

Shear wave velocity is one of the most important parameters for determining dynamic soil properties as well as for site characterization. Though there are several field tests to measure the shear wave velocity (V s ) but these are not always feasible. Hence, it is preferable to measure V s indirectly through empirical equations correlating V s with SPT-N value. Although, there are a number of empirical equations developed but these are region specific and cannot be used for all regions. In this paper, an effort has been made to develop new common empirical equations (considering different types of soil) correlating V s and SPT-N value, based on the existing correlations available for different continents collected almost from all regions which will be applicable to any region of the world. Empirical equations have been selected for analysis purpose from 41 different authors published worldwide, where, 26 equations are proposed for all soil types, 25 for sand and 14 are for clay type soil. These equations are selected separately and statistical regression analyses have been carried out to develop new common correlations for each type of soil. The newly developed equations have shown best fit curves with a very high R 2 values, along with minimum variance. As a result, it could be concluded that these newly developed correlations would be very much useful for determining shear wave velocity from known SPT-N value applicable to any region.