What is the primary method used in the dry auger or wet rotary soil boring method?

• A. Drilling with water only
• B. Using a rotary drill with air pressure
• C. Excavating with a hand shovel
• D. Rotating a drill while removing soil

Answer: (D)

The primary method used in the dry auger or wet rotary soil boring technique involves the rotation of a drill to penetrate the soil while simultaneously removing collected soil samples. This method is essential for gathering soil data, as it allows for the extraction of continuous soil cores or disturbed samples from the subsurface.

The rotating drill mechanism enables effective cutting through various types of soil and is critical for creating boreholes. In the case of the wet rotary method, water is often used to facilitate the drilling process and enhance soil removal, but the key action is still the rotation of the drill. This process is vital for subsurface exploration, providing crucial information about soil stratigraphy and characteristics.

The other answer choices do not adequately capture the comprehensive nature of the dry auger or wet rotary methods. For example, drilling with water only suggests a focus solely on fluid use without the crucial aspect of rotation. Similarly, relying on air pressure or using hand tools like shovels would not provide the same efficiency or depth of investigation as a rotary drilling system.