Michigan Residential Builders License Practice Test

What type of soil is described as coarse grained and gains strength from internal friction?

1. Clay soil

2. Granular soil

3. Sandstone soil

4. Silty soil

The correct answer is: Granular soil

The correct choice, granular soil, refers to a type of soil that is composed of larger particles, such as sand and gravel, which allows for the movement of air and water between those particles. This soil type gains strength primarily through internal friction, meaning that the individual grains lock together when compressed, providing stability. Granular soils typically have high shear strength and are able to drain water efficiently, making them suitable for many construction applications where stability and drainage are essential. In contrast, clay soil is generally made up of very fine particles that can retain water and expand when wet, behaving more like a plastic material than a granular one. Sandstone soil, while composed of sand, is not typically referred to in the context of soil classification in this manner and does not fit the description as cleanly as granular soil does. Silty soil contains finer particles than sand but lacks the internal stability and drainage characteristics of granular soil. Thus, granular soil is the best match for the description provided in the question.