Gravel is the second largest particle in soil. Gravel is just small pieces of larger rocks. Gravel ranges in size from 2mm to 64mm in diameter. The largest of the five particles is cobble. Cobbles are a rock fragment between 64 and 256mm in diameter that has been naturally rounded.
Bearing capacity is the amount of weight that a soil can hold without caving in .
The amount of each of the different components in a soil determines the bearing capacity of that soil. If you have a soil that contains a lot of clay and silt, the bearing capacity is much lower than a soil with more sand, gravel and cobbles. Typically, you would like to have your soil to have a bearing capacity between 1200-1500 pounds per square foot . Now, let s talk about how to find what type of soil you have. What you want to do is take a soil test.