Utilizing seismic techniques and dynamic field tests for soil dynamic response prediction in clay soils

When evaluating the dynamic response of soil, shear modulus is an essential parameter to consider. In most cases, the shear modulus is estimated using the shear wave velocity (Vs) of the soil as observed in field geophysical testing. Consequently, shear modulus is the main parameter for geotechnical earthquake engineering problems, both quantitatively and qualitatively. Its measuring must be done meticulously. In many cases, however, the shear wave velocity may be predicted using field dynamic tests such as the SPT N-value of soil when direct measurements of Vs are unavailable. There are various empirical formulae that associate soil type and SPT N-value to predict the shear wave velocity. On the other hand, all of these equations are based on several field observations related to specific places and geology. In this paper, different approaches for estimating the actual shear wave velocity measurements from SPT data were clarified and compared. The data of 59 boreholes in Al Nasiriya’s soil investigation were used. The standard penetration test data computations were applied. The current study investigated and possessed shear wave velocity based on Standard Penetration Test (SPT) N-values using the Excel application, then represented it in the Geographical Information System (GIS) and compared it with geophysical exploration. The SPT-Vs correlation generated for Al Nasiriya, Iraq, demonstrated a better degree of fitness for the dataset. There was also a suggestion for a site-specific SPT-Vs connection. On the other hand, most of the SPT-Vs expressions evaluations indicated a valuable predictive ability.