4.6
Properties (03 27xxx)
03 27001
maximum dry density
dry density (BS EN ISO 12570) or soil (01) obtained by a specified amount of compaction (03 24008) or the optimum moisture content (01)
03 27002
relative compaction
ratio of the dry density (BS EN ISO 12570) of a soil (01) to its maximum dry density (03 27001)
03 27003
Atterberg limits
limits of moisture content (11 27033) of a soil (01) below which a cohesive soil (03 23005) is no longer plastic and above which it is liquid
03 27004
dry density/moisture content relationship
relationship between dry density (BS EN ISO 12570) and moisture content (11 27033) of a soil (01) with a given amount of compaction (03 24008)
03 27005
clay fraction
03 27006
gravel fraction
03 27007
sand fraction
03 27008
silt fraction
03 27009
particle size distribution
03 27010
perched water table
water table (BS ISO 6107-3) maintained above the general standing water level of the ground (01) below
NOTE It is usually maintained by an impervious stratum (03 23001).
03 27011
pore water pressure
03 27012
total stress
03 27013
total pressure
pressure on a horizontal plane in a mass of soil (01), principally due to the weight (11 27002) of the overburden (03 23019)
03 27014
effective stress
difference between total stress (03 27012) and pore water pressure (03 27011)
NOTE For most purposes, that part of total stress (03 27012) borne by inter-particle contact.
03 27015
pore pressure ratio
ratio of the pore water pressure (03 27011) to the total pressure (04 27013)
03 27016
artesian
condition existing in an aquifer (BS ISO 6107-3) in which the head (01) of the water is sufficient to cause the water to rise above the surface of the ground (01)
03 27017
degree of saturation
ratio of the volume of water contained in voids (03 28003) to the total volume of voids (03 28003) in a material (01)
03 27018
percentage air voids
volume of air voids (03 28003) in a soil (01) expressed as a percentage of the total volume of the soil (01)
03 27019
skin friction
frictional resistance (11 27016) of surrounding soil (01) on the surface of structural members (01) below ground level (01)
cf. skin friction (03 36007)
03 27020
internal angle of friction
in granular soils (03 23013) the angle whose tangent, when multiplied by the force (01) normal to the assumed sliding surface, is equal to the shear strength (01) of the soil (01)
03 27022
angle of repose
steepest angle to the horizontal at which the sides of a heap of granular material (01) will be at rest
03 27025
slip surface
03 27026
slip circle
circular slip surface (03 27025)
03 27027
slip plane
slip surface (03 27025) in one plane
03 27028
toppling failure
failure (11 17012) of a rock (03 23027) slope (01) where steeply inclined discontinuities cause individual rock (03 23027) masses to overbalance
03 27029
wedge failure
failure (11 17012) by sliding of a wedge of rock (03 23027) or stiff clay (BS EN 12670) to the intersection of two or three well defined joint planes or fissures (BS EN 12670) behind a slope (01)
03 27030
drawdown
distance by which water table (BS ISO 6107-3) in or around a well (05 21002) or borehole (01) is lowered by pumping
03 27031
surcharge
material (01) or load (01) from one structural member (01) above formation (03 22043) either supported by a retaining structure (01) or used to increase the rate of consolidation (03 25020)
03 27032
earth pressure at rest
value of lateral pressure in a soil (01) mass, with a horizontal upper surface, completely at rest and undisturbed by any external force (01)
03 27033
active earth pressure
minimum value of lateral pressure in a soil (01) confined by a smooth vertical wall (01) as the wall (01) is moved away from the soil (01) mass allowing the soil (01) to expand until it reaches a state of equilibrium
03 27034
passive earth pressure
maximum value of lateral pressure in a soil (01) confined by a smooth vertical wall (01) as the wall (01) is moved towards the soil (01) mass causing the soil (01) to compress (01) until it reaches a limiting state when soil (01) failure (11 17012) occurs
03 27035
gross loading intensity
intensity of vertical loading on the ground (01) at the base of a foundation (01) due to all loads (01) above that level
03 27036
ultimate bearing capacity
value of the gross loading intensity (03 27035) for a particular foundation (01) at which the resistance of the soil (01) to displacement of the foundation (01) is fully mobilized
03 27037
net loading intensity
decrease or increase in intensity of vertical loading at the base of a foundation (01)
cf. net loading intensity (03 37001)
03 27038
presumed bearing value
net loading intensity (03 27037) considered appropriate to the particular type of ground (01) for preliminary design purposes
NOTE Usually obtained from a table.
03 27039
allowable net bearing pressure
net loading intensity (03 27037) taking into account the ultimate bearing capacity (03 27036), an appropriate factor of safety (01), the amount and kind of settlement (01) expected and the ability of the structure (01) to accommodate the settlement (01)
03 27040
A-line
line on a graph of liquid limit (BS EN ISO 14688-2) against plasticity index (BS EN ISO 14688-2), giving an empirical boundary between inorganic clays (BS EN 12670) and silty and organic soils (01)
03 27041
air voids line
line on a graph relating dry density (BS EN ISO 12570) to moisture content (11 27033) of a soil (01) that has a constant percentage of air voids (03 28003)
03 27042
saturation line
air voids line (03 27041) where the volume of air voids (03 28003) is zero
03 27043
bulb of pressure
contour line indicating assumed points of equal pressure below a foundation (01)
cf. bulb of pressure (03 37002)
03 27044
California bearing ratio
ratio of the force (01) required to achieve a given penetration of a prescribed piston into a soil (01) to the force (01) required to produce the same penetration into a standard sample (01) of crushed rock (09 23012)
03 27045
slope stability
03 27046
depth of cut-off
depth (01) reached by a diaphragm wall (01), sheet piling (01), contiguous bored piling (03 24003) or cofferdam (01) wall (01) below formation (03 22043)
03 27047
depth of penetration
total depth (01) below external ground level (01) reached by a caisson (01) or the sheet piling (01) of a cofferdam (01)
03 27048
foundation level
03 27049
soil profile
representation of a vertical section of soil (01) strata (03 23001) derived from a ground investigation (03 24002)
03 27050
haul
distance through which material (01) is transported
03 27051
chargeweight
weight of an individual explosive (BS 5607) charge used in a shot (03 26056) or lay-on blasting (03 24023)
4.7
Spaces (03 28xxx)
03 28001
shot hole
03 28002
firing point
place at which an explosion is initiated
03 28003
void
space (01) filled with fluids between particles