Usability of the surface wave method in assessment for subsurface investigation

Soil borehole drilling incorporating Standard Penetration Test (SPT) is frequently used for subsurface profiling and geotechnical calculations such as soil bearing capacity. Despite this conventional application, there are several limitations of soil boring and SPT involves. The primary objective is to propose an alternative method for geotechnical engineering application of soil profiling as supporting data by conducting Multichannel Analysis Surface Wave (MASW) for site investigation. In this study, the MASW was utilized to verify the reliability and capability of this method on conversion of shear wave velocity, Vs to SPT-N value. The calculated SPT-N value based on Vs using selected equation (Vs = 97N0.314) showed the reliability of the correlation between actual SPT-N value relationship was found strong (R2 = 0.8343). Results from the case study in general reveal the shear wave velocity (Vs) profile shows reading of 80 m/s to 160 m/s for the first 2-3 meter depth representing soft soil overlaying 2 meter layer of stiff soil with Vs between 130 m/s to 170 m/s followed by 4-10 meter hard material having Vs value between 190 m/s to 280 m/s before reaching harder stratum of 350 m/s and more. Therefore, the MASW can possibly be applied for SPT-N value determination as supporting data to the conventional SPT machine. The data of shear wave velocity also were correlated with actual SPT-N value so that the produced equation and can be applied based on the local region. Hence, produced empirical formulas from this study intend to provide the geotechnical engineer with a quick preliminary method of site investigation/assessment. © Published under licence by IOP Publishing Ltd.