What is the correct order of subsurface soil exploration?

The correct sequence of subsurface soil exploration involves first collecting samples of the soil, which is referred to as sampling. This initial step is crucial for understanding the soil composition and layering before any further actions are taken.

Following sampling, boring is the next step. Boring allows for the extraction of soil samples at various depths, providing a clear insight into the subsurface conditions and enabling the exploration team to gather more detailed information about the soil's characteristics in situ.

Finally, testing is performed on the samples collected. This step involves various laboratory analyses to assess properties such as soil type, density, moisture content, shear strength, and other geotechnical parameters necessary for foundation design and overall site evaluation.

This order—sampling first, followed by boring, and concluding with testing—ensures that the exploration process is systematic and effective, allowing for informed decisions based on the gathered data.