Development of a SPT&DCPT correlation for coarse-grained soils: A case study

Abstract. Standard Penetration Test (SPT) is a well-known in-situ test to identify the strength characteristics of investigated deposits for various type of soils. There are plenty of correlations to define the relationship between SPT blow counts and soil behavior per physical and mechanical properties defined by many researchers. The main aim to develop these correlations is to identify proper design parameters of layers for geotechnical design. Dynamic cone penetration test (DCPT) is also a well-known and practical method to identify the mechanical properties of soil layers such as subgrade characteristics and earthwork performance. Regarding to the advantage of DCPT by providing continuous data compared to SPT, developing correlations between SPT&DCPT may provide relatively more extensive dataset to perform data acquisition for geotechnical design. This study aims to define a site-specific SPT- DCPT relationship based on the comprehensive site investigation study for a renewable energy project held on Kingdom of Saudi Arabia (KSA) for various sites. The development of a relative density-based relationship between SPT & DCPT measurements are evaluated. The equivalent testing locations for both type of method is identified. The proposed relationship for all project site is checked individually. The compiled results are presented to identify the generalized relationship between SPT&DCPT results. The addressed relationship between SPT&DCPT are compared with the existing study results performed on similar type of lithology to verify the consistency.