The same idea often has a different name in Australia and New Zealand, the UK and the US. Each entry gives the names used in each place, a plain definition, and the drawing sheets that use it.
37 entries. A regional name appears only where a cited source supports it.
Soil formed by the in-place weathering of rock, widespread in Australia and New Zealand, with properties that grade into the parent rock and differ from transported soils.
SOURCES Wesley (2010)
The surface at which pore water pressure is atmospheric (the phreatic surface), below which soils are saturated and pore pressures are positive.
SOURCES Freeze & Cherry (1979)
A hole drilled into the ground to log the soil and rock, take samples and carry out tests at depth.
SHEETS GEOMAN-033 AUGER HEADS; GEOMAN-043 MONTABERT DRILL; GEOMAN-091 CORE BARREL DIAMETERS
SOURCES TMR Geotechnical Design Standard (AU); DMRB CD 622 (UK); FHWA GEC 5 Site Characterization (US)
A test that pushes a cone on rods into the ground at a steady rate and records the resistance at the tip and along a sleeve; the piezocone version also measures pore water pressure.
SOURCES ASTM D5778 (US); FHWA GEC 5 Site Characterization (US); TMR Geotechnical Design Standard (AU)
A hand-operated test that drives a cone with a falling weight and records penetration per blow, used for a quick strength profile of shallow ground and pavement layers.
SHEETS GEOMAN-027 DYNAMIC CONE PENETROMETER
SOURCES ASTM D6951 (US)
The planned work of finding out what the ground is made of and how it behaves at a site: desk study, site walkover, boreholes, pits, in situ tests and laboratory tests, reported for design.
SHEETS GEOMAN-027 DYNAMIC CONE PENETROMETER; GEOMAN-043 MONTABERT DRILL; GEOMAN-091 CORE BARREL DIAMETERS
SOURCES AS 1726:2017 (AU); TMR Geotechnical Design Standard (AU); BS 5930:2015+A1:2020 (UK); DMRB CD 622 (UK); FHWA GEC 5 Site Characterization (US)
The proportions of a soil sample in each range of grain size, found by sieving and sedimentation and plotted as a curve of percentage finer against size.
SHEETS GEOMAN-053 PARTICLE SIZE DISTRIBUTION; GEOMAN-038 COMPUTERIZED PARTICLE ANALYZER (CPA)
SOURCES ASTM D6913 (US)
Rock Quality Designation: the percentage of a core run recovered as sound, intact pieces at least 100 mm long, logged from borehole core as a quick index of rock mass quality.
SOURCES ASTM D6032/D6032M-17
A test in a borehole that drives a split-barrel sampler into the ground with a standard hammer; the N value counts the blows for the last 300 mm of a 450 mm drive (the first 150 mm is a seating drive), often corrected for hammer energy to N60.
SOURCES NZGS Field Description of Soil and Rock (NZ); TMR Geotechnical Design Standard (AU); ASTM D1586 (US)
A shallow excavation, usually dug with an excavator, that lets the ground be seen, logged and sampled in place.
The liquid limit and plastic limit, whose difference is the plasticity index, defining the range of water content over which a fine-grained soil behaves plastically, central to classification and to estimating strength and compressibility.
SOURCES ASTM D4318; AS 1289.3.9.1
The slow compression of a saturated soil as water drains out under a new load and the load passes from the water to the soil grains.
SHEETS GEOMAN-031 COEFFICIENT OF VOLUME COMPRESSIBILITY
SOURCES TMR Geotechnical Design Standard (AU); FHWA GEC 5 Site Characterization (US); ASTM D2435 (US)
Total stress minus pore water pressure in a saturated soil: the part of the stress carried through the contacts between soil grains, which controls strength and compression; in unsaturated soils suction acts as a second stress variable.
SHEETS GEOMAN-030 EFFECTIVE STRESS; GEOMAN-034 UNSATURATED SOILS; GEOMAN-055 DRAINED AND UNDRAINED
SOURCES TMR Geotechnical Design Standard (AU); FHWA GEC 5 Site Characterization (US)
Clay that swells as it takes up water and shrinks as it dries, moving light structures and pavements built on it.
SHEETS GEOMAN-099 SWELLING SOIL; GEOMAN-101 EXPANSIVE SOIL; GEOMAN-102 SOIL SUCTION; GEOMAN-105 CHARACTERISTIC SURFACE MOVEMENT; GEOMAN-106 SHRINKAGE INDEX
Loss of strength in loose saturated sand or silt when pore water pressure rises until the grains are no longer pressed together, usually under earthquake shaking.
SHEETS GEOMAN-080 STATIC LIQUEFACTION
SOURCES TMR Geotechnical Design Standard (AU); FHWA GEC 5 Site Characterization (US)
The pressure of the water in the spaces between soil grains or in rock joints, positive below the water table and negative (suction) in unsaturated soil above it.
SHEETS GEOMAN-030 EFFECTIVE STRESS; GEOMAN-048 BASEMENT PRESSURE
SOURCES TMR Geotechnical Design Standard (AU); FHWA GEC 5 Site Characterization (US)
Where a sand or gravel sits between its loosest and densest possible packing, from the void ratio, usually given as a percentage.
SHEETS GEOMAN-014 RELATIVE DENSITY
SOURCES NZGS Field Description of Soil and Rock (NZ); FHWA GEC 5 Site Characterization (US)
The shear strength of a saturated clay (or other fine-grained soil) loaded too quickly for water to drain in or out, so it shears at constant volume while excess pore pressures develop; written su, it depends on the water content, not on the total stresses applied during the test.
SHEETS GEOMAN-055 DRAINED AND UNDRAINED; GEOMAN-056 DRAINED AND UNDRAINED
The sloping face of a cutting or an embankment, usually given as a ratio of vertical to horizontal. US practice writes the slope ratio horizontal:vertical, so a US 3:1 is the same physical slope as the AU/NZ 1V:3H (1 in 3).
SHEETS GEOMAN-077 SLIP CIRCLES
SOURCES TMR Geotechnical Design Standard (AU); DMRB CD 622 (UK)
An excavation through higher ground to carry a road or railway at a lower level, with a slope or a wall on each side.
SHEETS GEOMAN-077 SLIP CIRCLES
SOURCES TMR Geotechnical Design Standard (AU); DMRB CD 622 (UK); FHWA GEC 5 Site Characterization (US)
The movement of a mass of rock, soil or debris down a slope.
SHEETS GEOMAN-042 LANDSLIDE CAUSES; GEOMAN-050 LANDSLIDES
SOURCES TMR Geotechnical Design Standard (AU); USGS Fact Sheet 2004-3072 (US)
A hole or depression in the ground surface formed when soil or rock above a void sags or collapses into it, often where soluble rock has been dissolved. The standard international karst term for the closed depression is doline.
SHEETS GEOMAN-044 PITTSBURGH SINKHOLE
SOURCES FHWA GEC 5 Site Characterization (US); USGS Sinkholes (US)
Excavating, moving, placing and compacting soil and rock to form the ground to the shape a project needs.
SHEETS GEOMAN-060 EARTHWORKS MONITORING; GEOMAN-068 DYNAMIC COMPACTION
SOURCES TMR Geotechnical Design Standard (AU); DMRB CD 622 (UK)
A raised bank of compacted fill that carries a road or railway, or holds back water.
SHEETS GEOMAN-060 EARTHWORKS MONITORING
SOURCES TMR Geotechnical Design Standard (AU); DMRB CD 622 (UK); FHWA GEC 5 Site Characterization (US)
Ground placed by people rather than formed naturally. Engineered fill is placed and compacted to a specification; uncontrolled fill is not, and can settle badly.
SHEETS GEOMAN-068 DYNAMIC COMPACTION
SOURCES TMR Geotechnical Design Standard (AU); BGS Lexicon: Made Ground (UK); DMRB CD 622 (UK); FHWA GEC 5 Site Characterization (US)
The subgrade is the ground below a pavement. A capping layer is a layer of selected or treated material placed on a weak subgrade to give a better platform for the pavement.
SHEETS GEOMAN-015 PAVEMENT DESIGN; GEOMAN-012 RAIL TRACK GEOTEXTILES
SOURCES DMRB CD 622 (UK)
Treating weak or compressible ground in place, for example by compaction, drainage, mixing in binders or adding stiff columns, so it can carry the planned load.
SHEETS GEOMAN-045 CUTTER SOIL MIXING; GEOMAN-063 LIME; GEOMAN-068 DYNAMIC COMPACTION; GEOMAN-022 STABILISED SAND
SOURCES TMR Geotechnical Design Standard (AU); FHWA GEC 5 Site Characterization (US)
Fill placed temporarily on soft ground to pre-compress it, usually with vertical drains, and removed once enough settlement has occurred before construction.
SOURCES FHWA NHI-16-028
A prefabricated vertical drain, a geotextile-wrapped plastic strip pushed into soft clay, that shortens the drainage path and speeds consolidation under a surcharge.
SOURCES FHWA NHI-16-028
A wall installed into the ground before excavation, such as a sheet pile, contiguous pile, secant pile or diaphragm wall, that relies on the resistance of the ground in front of its embedded length, with props or anchors added for deeper excavations.
SHEETS GEOMAN-004 EMBEDDED RETAINING WALLS; GEOMAN-011 SECANT CONTIGUOUS SOLDIER WALLS; GEOMAN-039 EMBEDDED RETAINING WALLS; GEOMAN-048 BASEMENT PRESSURE
A prestressed tendon grouted into the ground beyond a free length, used to hold back a wall or slope or to resist uplift.
SHEETS GEOMAN-009 DIFFERENCE? GROUD ANCHOR & SOIL NAIL; GEOMAN-036 GROUND ANCHOR LOAD DISTRIBUTION; GEOMAN-070 DEADMAN ANCHOR
SOURCES TMR Geotechnical Design Standard (AU); FHWA GEC 4 Ground Anchors (US)
A steel bar grouted into a drilled hole in a cut slope or wall face, not prestressed, that reinforces the ground as it starts to move.
SHEETS GEOMAN-009 DIFFERENCE? GROUD ANCHOR & SOIL NAIL
SOURCES TMR Geotechnical Design Standard (AU); DMRB CD 622 (UK); FHWA GEC 7 Soil Nail Walls (US)
The ratio of available to mobilised strength (or resisting to disturbing forces) used in checks such as slope stability and bearing capacity, held above a value set by codes and accepted practice.
SOURCES AS/NZS 1170.0:2002
The design framework of the Australian, New Zealand and European codes, in which the ground and structure are checked against exceeding defined states: instability or collapse (ultimate) and excessive deformation (serviceability).
SOURCES AS/NZS 1170.0:2002
The pressure a foundation can apply to the ground before the ground fails in shear (the ultimate bearing capacity); design is checked against an allowable bearing pressure, reduced from it by a factor of safety.
SHEETS GEOMAN-059 SQUARE FOOTING; GEOMAN-008 TRANSCONA GRAIN SILO COLLAPSE; GEOMAN-094 HELICAL PILE BEARING CAPACITY
SOURCES TMR Geotechnical Design Standard (AU); FHWA GEC 6 Shallow Foundations (US)
A long, slender deep-foundation element, driven, jacked or bored, that carries load down through weak strata by shaft friction and end bearing.
SOURCES Tomlinson & Woodward (2014)
The downward movement of a foundation or the ground surface under load, comprising immediate and consolidation components, and often the governing design check on soft ground.
SOURCES Das & Sivakugan (2018)