The unbroken, solid rock that underlies all unconsolidated material on the earth's surface

A large, naturally rounded rock, lying on the surface of the ground or partially embedded in it

A naturally rounded, stone, smaller than a boulder and larger than a pebble, used for rough paving, walls, and foundations

The fertile surface layer of soil, as distinct from the subsoil

The bed or layer of earth immediately beneath the surface soil

Soil containing a large amount of organic matter, usually very compressible and having poor load-sustaining properties

Small pebbles and stone, or a mixture of these with sand, formed either naturally or by crushing rock

A loose, granular material resulting from the disintegration of rocks, consisting of grains smaller than gravel but coarser than salt

A natural, earthy material that is plastic when moist but hard when fired and is used for making brick, tile, and pottery

Gravel having one or more fractured faces produced by mechanically crushing

Stone having well-defined edges produced by the mechanical crushing of rocks or boulders

A small-diameter, natural gravel

A small, rounded stone, especially one worn smooth by the action of water

A well-graded, naturally occurring sand often used as a base or sub-base material

Loose sedimentary material consisting of fine mineral particles

A diagram of a vertical section of soil from the ground surface to the underlying material, showing a succession of horizons developed by weathering, deposition, or both

Any of a series of relatively distinct layers of soil or its underlying material found in a vertical section of a land

A single bed or layer of sedimentary earth or rock having the same composition throughout, lying between beds of another kind

Soil containing 27% to 40% clay and 20% to 45% sand

A clay formed by the decomposition of volcanic ash, having the ability to absorb large amounts of water and to expand to several times its natural volume

A rich soil containing a relatively equal mixture of sand and silt and a smaller proportion of clay and organic matter

An unstratified, cohesive, loamy deposit deposited by wind

The levels of water content defining the boundaries between the different states of consistency of a plastic or cohesive soil, as determined by standard tests

The water content, expressed as a percentage of dry weight, at which a soil passes from a plastic to a liquid state

The water content, expressed as a percentage of dry weight, at which a soil loses its plasticity and begins to behave as a solid

The water content, expressed as a percentage of dry weight, at which a reduction in water content will not cause a further decrease in the volume of a soil mass

The numerical difference between the liquid limit and the plastic limit of a soil

Any gravel, sand, or silt that exhibits no cohesiveness or plasticity

The property of a porous material that allows a gas or liquid to pass through its pore spaces

A soil that can be rolled into threads 1/8 in. (3.2 mm) in diameter without crumbling

Any permeable soil that allows the relatively free movement of water

Any fine-grained soil, such as clay, having pores too small to permit water to pass except by slow capillary action

Soil that has considerable strength when unconfined and air-dried, and significant cohesion when submerged

Soil that has little or no strength when unconfined and air-dried, and little or no cohesion when submerged

The ratio of a volume of void spaces to the volume of solid particles in a soil mass

The void ratio corresponding to the critical density of a soil mass

Of or pertaining to the practical applications of geological science in civil engineering

The investigation and classification of a foundation soil based on observation and tests of material disclosed by borings or excavations to obtain the information necessary for the design of a foundation system

The branch of civil engineering that deals with the mechanical behavior of soil when compressed or sheared, or when water flows through it

The arrangement and aggregation of soil particles in a soil mass

An undisturbed, cylindrical sample of earth or rock obtained by means of a core drill and used for analysis and testing of bearing capacity. Also called boring.

The consolidation of sediment by the weight of overlying deposits, or a similar compression of soil, aggregate, or cementitious material by rolling, tamping, or soaking

The water content of a soil at which maximum density can be attained through compaction

A test for measuring the density of granular soils and the consistency of some clays at the bottom of a borehole, recording the number of blows required by a hammer to advance a standard soil sampler

The unit load required to produce a specified penetration into a soil at a specified rate of penetration

The property of a soil that enables its particles to resist displacement with respect to one another when an external force is applied, due largely to the combined effects of cohesion and internal friction