Empirical Correlation between Standard Penetration Resistance (SPT-N) and Shear Wave Velocity (V-s) for Soils in Metro Manila, Philippines

The measurement of the shear wave velocities (V-s) of soils is an important aspect of geotechnical and earthquake engineering, due to its direct relation to the shear modulus (G), which in turn influences the stress-strain behavior of geomaterials. V-s can be directly measured or estimated using a variety of onsite tests or in a laboratory. Methods such as downhole PS logging require boreholes and may not be logistically and economically feasible in all situations. Many researchers have estimated V-s from other geotechnical parameters, such as standard penetration test resistance (SPT-N), by means of empirical correlations. This paper aimed to contribute to this subject by developing an empirical relationship between V-s and SPT-N. Data from twenty sites in Metro Manila were obtained from geotechnical investigation reports. V-s profiles of the same sites were also acquired using the refraction microtremor method. New empirical relationships were developed for all, sandy, and clayey soil types, using a non-linear regression method that is applicable for Metro Manila soils. Statistical evaluation and comparison of the proposed correlations with other previous works suggested the viability of the empirical model.