The Official Soil Series Description (OSD) database is a national collection of more than 20,000 detailed soil series descriptions. These descriptions, in a text format, serve as a national standard.

Soil classification deals with the systematic categorization of soils based on distinguishing characteristics as well as criteria that dictate choices in use. Soil classification is a dynamic subject, …

Where soils are configured in layers, i.e., where a layered geologic structure exists, the soil must be classified on the basis of the soil classification of the weakest soil layer.

Nov 23, 2025 · The two principal systems of soil classification in use today are the soil order system of the U.S. Soil Taxonomy and the soil group system, published as the World Reference Base for Soil …

The Unified Soil Classification System uses a two-letter system to name different soil types. The chart below also includes a plasticity chart that is used to determine the classification of fine-grained soils.

Jan 20, 2024 · In geotechnical engineering, soil classification serves as a crucial framework for standardizing soil descriptions and grouping similar soils based on characteristics that profoundly …

A soil classification system is a universal language which all the geotechnical engineers understand, where soils of similar behaviour are grouped together, and systematic and rational ways are …

Different systems have been developed in different countries, so in this section we will cover the basics of the classification system commonly used in the US, as well as the younger world reference base …

Oct 24, 2025 · What Is Soil? Soil is a mixture of organic materials, minerals, organisms, air, and water that provide the medium for plant growth. Soil is also important for construction as it is the material …

Determine percentages of sand and gravel from grain-size curve. Depending on percentage of fines (fraction smaller than No. 200 sieve size), coarse-grained soils are classified as follows: Less than 5 …