Using Miniature Cone Penetration Test (Mini-CPT) to determine engineering properties of sandy soils

Abstract

In-situ testing techniques have proven to be successful in improving the speed and reliability of geotechnical investigations. One of the most common in-situ methods in engineering geology and site investigation is Cone Penetration Test (CPT), which is mainly used for characterization of soils, as it is a robust, simple, fast, reliable and economic test that can provide continuous soundings of subsurface soil. Miniature Cone Penetration (Mini-CPT) Test is a new type of CPT but in diameter less than conventional CPT to determine the bearing capacity and strength parameters of loose to semi-dense soils at shallow depth. Mini-CPT needs lower force to penetrate into the soil, and its ability to identify very thin underneath layers is higher than CPT. In this research, a Mini-CPT apparatus was used in laboratory conditions to define the relationships between tip resistance (qc(MCPT)), friction resistance (f‌s(MCPT)) and some engineering properties of poorly graded sandy soils such as Relative Density (Dr), Friction Angle (?), Elastic Modulus (E), Shear Modulus (G), and the Modulus of Subgrade Reaction (Ks) with different densities. Based on the results of the experiments, the relationships between both the qc(MCPT) and fs(MCPT) with engineering properties were obtained with a high determination coefficient (R2>0.85).