A Correlation Between P-Wave Velocities and Standard Penetration Test (Spt-N) Blows Count for Meta-Sedimentary Soils of Tropical Country

Abstract

The conceptual foundation design acquires geotechnical parameters such as stiffness, elastic, strength, etc. As such, geophysical method such as seismic refraction may assist in providing parameters for geotechnical analysis and design. Using seismic methods, the information on the stiffness of the ground can be obtained. This study has been carried out to develop the correlation between P-waves velocity from seismic refraction method against Standard Penetration Test (SPT) N value from existing borehole data. The study area was located at Bandar Country Homes, Rawang, Selangor which was believed to be underlained by Terolak Formation, a geological formation consisting of meta-sedimentary rock. Three seismic lines were conducted across six numbers of existing boreholes with the aim of characterizing the subsurface of the study area. Interval of each geophone was set to 5 m with the total length of each seismic line 120 m. The seismic sources were used by 12 lbs sledge hammer and steel plate, then seismograph data received by geophones (24 Hz) and saved in ABEM Terralock MK6 as seismogram. The high quality data obtained was then processed using SeisOpt Picker and SeisOpt@2D software to produce a seismic tomography section for each survey line. The correlation was made between seismic velocities and SPT-N value at the same depth. The findings from this study, a linear regression was found to enhance the relationship between Vp and SPT-N value. Also, the subsurface information together with depth of each geomaterial at the study area could be determined. Thus, this study may assist engineers for estimating and predicting the properties of the subsurface geomaterials in meta-sedimentary soils especially in reducing the cost of site investigation and enhance the knowledge of understanding earth’s subsurface characterizations physical parameters.