Comprehensive review of cone penetration test calibration chamber for soil: Equipment and data interpretation

With the growing trend of seeking resources, the significance of infrastructure construction in the upper part of soils has become increasingly prominent. Studying the geotechnical characteristics of soils is crucial for the safe operation of geotechnical projects and the efficient deep-resource development. The cone penetration test (CPT) indirectly measures the geotechnical properties of soils. However, Parkin and Lunne pointed out that the CPT data obtained solely on site cannot be reliably converted into soil mechanical parameters. It is difficult to obtain undisturbed samples of soils for laboratory tests (such as triaxial and pedometric tests), thus making it impossible to accurately obtain their mechanical parameters, resulting in a lack of comparison in the interpretation of in situ CPT data. Furthermore, due to the differences in testing procedures, experimental equipment, and soil types among various regions, the data and findings from CPT cannot be generalized into universal principles to guide engineering practices. CPT calibration chamber (CCC) testing, as an effective method to establish the correlation between laboratory measurements of soil and its in situ mechanical properties, holds significant research value for soils where undisturbed samples cannot be retrieved (such as cohesion-less sands and silty soils without plasticity). This paper first reviews the characteristics of large and small CCC equipment for different types of soil. It then discusses the boundary effect encountered in the interpretation of CCC test data and general solutions and summarizes the proposed empirical relationships based on CCC test data for geotechnical parameters. Finally, it outlines future directions for CCC equipment and data interpretation methods.