Which test determines the in-situ dry density of soil?

The core cutter method is a direct field test that effectively determines the in-situ dry density of soil. This method involves using a cylindrical metal cutter that is inserted into the ground to obtain an undisturbed soil sample. Once the sample is extracted, the volume of the cutter is known, allowing for the calculation of the dry density by measuring the weight of the soil sample and dividing it by its volume.

The core cutter method is particularly useful for assessing the compaction and density characteristics of soil on-site, making it invaluable for construction and geotechnical engineering projects. Its application provides accurate results for in-situ conditions, which are crucial for understanding the soil's properties before construction begins.

Other methods mentioned, such as the Standard Penetration Test (SPT), primarily evaluate soil resistance and provide indirect information about density, while the Standard Proctor test and Direct shear test focus on laboratory-based assessments that may not directly reflect in-situ conditions.