According to the Unified Soil Classification System (USCS), what is the term for soil grains with size greater than 4.75 mm but less than 75 mm?

The Unified Soil Classification System (USCS) categorizes soil based on the size of its grains, and soils are classified into various types according to specific size ranges. In this system, soil grains that range in size greater than 4.75 mm and less than 75 mm are classified as gravel.

Gravel consists of coarse particles that can be further divided into different sizes, typically categorized as fine gravel (4.75 mm to 20 mm) and coarse gravel (20 mm to 75 mm). The delineation of gravel within this range is important in geotechnical engineering as it influences soil's drainage characteristics, strength, and suitability for construction purposes.

Understanding these classifications helps engineers and geologists make informed decisions regarding material usage, site suitability, and construction methods, which are critical in fields like hydraulics, pneumatics, and geotechnical engineering.