Soil that remains in clumps when excavated is cohesive. Soil that breads up easily and does not stay in clumps is granular. Observe the side of the opened excavation and the surface area adjacent to the excavation. Crack-like openings such as tension cracks could indicate fissured material. If chunks of soil spall off a vertical side, the soil could be fissured.
Small spalls are evidence of moving ground and are indications of potentially hazardous situations.
Examine layered systems to identify if the layers slope toward the excavation. Estimate the degree of slope of the layers. Manual analysis of soil samples in conducted to determine quantitative as well as qualitative properties of soil and to provide more information in order to classify soil properly. Cohesive material can be successfully rolled into threads without crumbling. If the soil is dry and falls into clumps which break up into smaller clumps, but the smaller clumps can only be broken up with difficulty, it may be clay in any combination with gravel, sand or silt.