Construction Safety Orders Article 6. This appendix describes a method of classifying soil and rock deposits based on site and environmental conditions, and on the structure and composition of the earth deposits. The appendix contains definitions, sets forth requirements, and describes acceptable visual and manual tests for use in classifying soils. A soil in which the particles are held together by a chemical agent, such a calcium carbonate, such that a hand-size sample cannot be crushed into powder or individual soil particles by finger pressure. Cohesive soil does not crumble, can be excavated with vertical side slopes, and is plastic when moist.
Cohesive soil is hard to break up when dry, and exhibits significant cohesion when submerged.
Cohesive soils include clayey silt, sandy clay, silty clay, clay and organic clay. Soil that does not exhibit visible signs of moisture content. A soil material that has a tendency to break along definite planes of fracture with little resistance, or a material that exhibits open cracks, such as tension cracks, in an exposed surface. Granular soil has no cohesive strength. Some moist granular soils exhibit apparent cohesion.