Glossary
Geotechnical, testing and GeoCRM terminology.
Geotechnical terms
AHD — Australian Height Datum. The vertical reference for reduced levels.
CBR — California Bearing Ratio. A measure of subgrade strength used in pavement design. Can be measured in the laboratory (AS 1289 6.1.1) or estimated from a DCP.
CPT — Cone Penetration Test. An in-situ test pushing an instrumented cone into the ground.
DCP — Dynamic Cone Penetrometer. A hand-operated field test measuring penetration per blow.
DCPI — DCP Index. Penetration in millimetres per blow. Low values indicate stiff material.
GDA2020 / MGA — Geocentric Datum of Australia 2020 and Map Grid of Australia. The horizontal coordinate system.
Lithology — the description of ground materials and their sequence with depth.
MDD — Maximum Dry Density. The peak dry density from a compaction relationship test.
OMC — Optimum Moisture Content. The moisture content at which maximum dry density is achieved.
PID — Photoionisation Detector. Used for screening volatile organic compounds.
RL — Reduced Level. Elevation relative to a datum, normally AHD.
SPT — Standard Penetration Test. Blow counts recorded as the sampler is driven; reported as an N value.
Strata — distinct ground layers.
UCS — Unconfined Compressive Strength.
VST — Vane Shear Test. In-situ shear strength measurement in soft cohesive soils.
WGS 84 — the global datum used for latitude and longitude.
Testing terms
Density ratio — field dry density as a percentage of maximum dry density. The value most compaction specifications are written against.
Moisture ratio — field moisture content as a proportion of optimum moisture content.
Moisture variation — the difference between field moisture content and optimum.
Oversize correction — adjustment to density results for coarse material excluded from the laboratory test.
GeoCRM terms
Docket — the field record of work done on a job. Created automatically with every job, and the basis for sign-off, reporting and invoicing.
Ground log — a subsurface investigation, holding one or more investigation locations.
Investigation location — a single borehole, trial pit, CPT or monitoring well.
Work request — a laboratory job holding samples and their worksheets.
Worksheet — one test on one sample.
Utilisation — in a calculation, the proportion of available capacity used by the applied load.