Soil Engineering: Common Terms and Definitions
Soil Engineering Common Terms (A-Z)
ABSORBED WATER
ACTIVE ZONE
ADHESION
ADSORBED WATER
AEOLIAN DEPOSITS
ALLOWABLE BEARING PRESSURE
ALLUVIAL SOIL
ANGLE OF FRICTION
ANGLE OF INTERNAL FRICTION
ANGLE OF REPOSE
Angle of Repose – Angle between the horizontal and the maximum slope that soil assumes through natural processes. It generally applies to dry granular soils.
ANISOTROPIC SOILS
APPARENT COHESION
AQUIFER
ATTERBERG LIMITS
AUGER
BANK RUN
BEARING CAPACITY
Bearing capacity of soil is the value of the average contact pressure between the foundation and the soil which will produce shear failure in the soil. Ultimate bearing capacity is the theoretical maximum pressure which can be supported without failure. Allowable bearing capacity is what is used in geotechnical design, and is the ultimate bearing capacity divided by a factor of safety.

BEARING CAPACITY FAILURE
BEARING WALL
BEDROCK
BELL
BENTONITE CLAY
BENTONITE SLURRY
BLOW COUNT
BOREHOLE
BOULDERS
CAPILLARY RISE
CASING
CLAY SOIL
COBBLE
COEFFICIENT OF COMPRESSIBILITY
COEFFICIENT OF CONSOLIDATION
COEFFICIENT OF PERMEABILITY
COEFFICIENT OF PERMEABILITY₁₂
COHESION
COLLOIDS
COLLUVIAL SOIL
COMBINED FOOTING
COMPACTIBILITY
COMPACTION
Compaction – the densification of a soil through mechanical means.

COMPACTION CURVE
COMPACTION TEST
COMPRESSIBILITY
COMPRESSIVE STRENGTH
CONE PENETRATION TEST (CPT)
CONSOLIDATION
CONSOLIDATION TEST
CONSOLIDOMETER
CONSTANT HEAD PERMEAMETER
CORE
CORE BIT
CORE DRILLING
CRUSHED STONE
CUMULATIVE PERCENT RETAINED
DEGREE OF CONSOLIDATION
DEGREE OF SATURATION
DESSICATION
DEWATERING
Dewatering – the process of removing water from a construction area, such as by pumping from sumps or from wells. Normally, a temporary measure.

DILATANCY
DIRECT SHEAR TEST
DISTURBED SOIL SAMPLE
EFFECTIVE DIAMETER
EFFECTIVE PRESSURE, EFFECTIVE STRESS
ELASTICITY
Elasticity – property of material that returns to its original form after applied force is removed.
Here is an excellent resource to measure Soil Elasticity utilizing a triaxal apparatus. Link
By Pierre-Yves Hicher, (Prof., Lab. of Mech., Soils, Struct., Mat., CNRS URA 850 Ecole Centrale de Paris, 92295, Chateney-Malabry, France) Journal of Geotechnical Engineering, Vol. 122, No. 8, August 1996, pp. 641-648, (doi: http://dx.doi.org/10.1061/(ASCE)0733-9410(1996)122:8(641))
EXCESS PORE WATER PRESSURE
EXPANSIVE SOIL
FAILURE
FAILURE CRITERION
FAT CLAY
FILTER
FINES
FISSURES
FOOTING
FOUNDATION
FREE WATER
FREEZE
FRIABLE
FROST HEAVE
Frost Heave – the heaving of the ground due to the formation of ice lenses.

FROST SUSCEPTIBLE SOIL
GAP-GRADED
GEOTEXTILES
GLACIAL TILL
GRADATION
GRAIN-SIZE DISTRIBUTION
GRAVEL
Gravel – rounded or semirounded particles of rock that pass a 3-in. (76.2-mm) sieve and are retained on a No.4 U.S. standard sieve (4.75 mm).

GRIZZLY
GROUNDWATER LEVEL
HARDNESS
Hardness – resistance of a given material to indentation or scratching.

HARDPAN
HEAD
HEAVE
HETEROGENEOUS SOIL MASS
HOMOGENEOUS SOIL MASS
HORIZON
HUMUS
HYDRAULIC FILL
HYDRAULIC GRADIENT
HYDROMETER
HYDROSTATIC PORE WATER PRESSURE
IN-SITU
ISOTROPIC
KIP
LANDSLIDE
LATERAL EARTH PRESSURE
LEACHING
LEAN CLAY
LIQUEFACTION
LIQUID LIMIT (AN ATTERBERG LIMIT, LL)
LIQUIDITY INDEX
LOAM
LOESS
MANHOLE
MENISCUS
MODULUS OF ELASTICITY
MOHR FAILURE ENVELOPE
MOISTURE CONTENT
MOISTURE-DENSITY CURVE
MUCK
MUD
NORMAL FORCE
NORMALLY CONSOLIDATED SOIL
OPTIMUM MOISTURE CONTENT
ORGANIC SOIL
OUTCROP
OVERBURDEN
OVERCONSOLIDATED SOIL
PARENT ROCK
PEAT
PENETRATION RESISTANCE (SPT)
PENETROMETER
PERCENT COMPACTION
PERCHED WATER TABLE
PERCOLATION
PERCOLATION ("PERC") TEST
PERMAFROST
PERMEABILITY
PH
PIEZOMETER
PILE
PIPING
PLASTIC LIMIT (AN ATTERBERG LIMIT, PL)
PLASTICITY
PLASTICITY INDEX (PI)
PORE WATER PRESSURE
POROSITY
PRECONSOLIDATION PRESSURE
PRELOADING
PROCTOR CURVE
QUICK CLAY
REFUSAL
RELATIVE DENSITY
REMOLDED SOIL
RESIDUAL SOIL
RIPPABLE / RIPPABILITY
RIPPER
Ripper – a long, chisel like tool attached to a dozer or other equipment used to loosen hard-packed material

ROCK
SAND
SAND BOIL
SAND CONE METHOD
SEEPAGE
SEEPAGE FORCE
SELECT FILL
SHEAR
SHEAR FAILURE
SHELBY-TUBE SAMPLER
SHRINKAGE LIMIT (AN ATTERBERG LIMIT, SL)
SIEVE
SIEVE ANALYSIS
SILT
SLAKE DURABILITY
SOIL
SOIL MECHANICS
SOIL PROFILE
SOIL STABILIZATION
SPECIFIC GRAVITY OF SOLIDS
SPLIT-SPOON SAMPLER
Split-Spoon Sampler – device used for obtaining soil samples in a predrilled hole and from some depth beneath the surface. The split-spoon sampler is a tube that is driven into the soil to be sampled. The sampler is opened by splitting it longitudinally to retreieve the soil sample from within. Part of the Standard Penetration Test (SPT).

STANDARD PENETRATION TEST (SPT)
STONE
Stone – crushed or naturally angular particle of rock that will pass a 3-in. (75 mm) sieve and be retained on a No. 4 (4.75-mm) U.S. standard sieve.
