Interpretation of CPTu and SPT data about sandy soils in the Plovdiv region

CPTu (Piezocone Penetration Test) and Penetration tests – SPT (Standard Penetration Test) are the most used in situ tests in order to map a soil stratigraphy and determine the geotechnical parameters of construction soils. A comparison has been made between the relative density values obtained on the basis of the two types of field trials. The soils examined are classified according to well-established classification diagrams. The sandy soils are described in the range of dense to very dense. They have good strength and deformation characteristics – with a high friction angle and high Young’s modulus but the presence of a high level of groundwater is a prerequisite for their liquefaction under dynamic impacts.