Soil classification method for port and waterway engineering based on piezocone penetration test

Soil classification is one of the key issues in geotechnical investigation and design. And soil classification based on cone penetration test with pore water pressure measurement (CPTU) is an efficient and pragmatic method. The classification standards of existing methods are not consistent with Chinese code for geotechnical investigation on port and waterway engineering (JTS133-2013). Therefore, developing a CPTU-based soil classification method for port and waterway engineering is an urgent and meaningful task. This objective is achieved in this study by collecting database from a large number of worldwide water transportation projects including 616 CPTU and corresponding sampling boreholes, with spacing less than 5 m between them, and comparing and analyzing data and corresponding laboratory test results. Seven existing CPTU-based soil classification charts are selected for performance evaluation using the compiled CPTU and soil type database. It is shown that the stress normalization methods employed in existing soil classification charts may have limitation in shallow soils. A more adequate CPTU-based soil classification method is developed by introduction of new stress normalization method and modification of zone boundaries. It is implied that the proposed method can properly describe the general variation of soil types from CPTU data, particularly for soft soils, silty or fine sands and medium to coarse sands. And the developed CPTU-based soil classification method will provide a more accurate result as compared other existing methods in Chinese port and waterway engineering. © 2022, Editorial Office of Rock and Soil Mechanics. All right reserved.