The transformation of numerical digital information from sensors into a corrected, ordered, and simplified form such as Engineering Units.
A dam is a hydraulic structure of fairly impervious material built across a river to create a reservoir on its upstream side for impounding water for various purposes.
The formula used for laminar flow of water through porous saturated soils.
Velocity of flow = hydraulic conductivity x hydraulic gradient.
A design whereby structural load is transmitted to a soil at some depth, usually through piers, piles, or caissons.
Degree of consolidationThe proportion of consolidation that has occurred after a given elapsed time. Particularly important in soft soil embankments.
Degree of saturationThe proportion of the volume of water to the total volume of voids of a given mass of soil.
DensityThe ratio of the total mass to the total volume of a unit of soil. Usually expressed as a unit weight where weight is interchanged with mass. Units: lbm/ft³, kg/m³.
Density of soil grainsThe average density of the mineral or rock of which the soil particles are composed.
Density of waterThe density of water will vary with temperature and pressure. Values used for soils analysis are 62.4 lbm/ft³, 9.81 kN/m³ or 1000 kg/m³. A value of 64.0 lbm/ft³ is the value for sea water.
Depth factorOne of the terms in the bearing capacity equation that relates to depth of the foundation. The ratio between the depth of a slip circle below the top of a slope and the height of the slope.
DesiccationThe process of shrinkage or consolidation of the fine-grained soil produced by increase of effective stresses in the grain skeleton accompanying the development of capillary stresses in the pore water.
DewaterLowering the groundwater table below or behind a structure to allow it to be constructed in a stable condition.
Diaphragm wallDiaphragm walling refers to the in-situ construction of vertical walls by means of deep trench excavations. Stability of the excavation is maintained by the use of a drilling fluid, usually a Bentonite suspension. The continuous diaphragm wall (also referred to as slurry wall in the US) is a structure formed and cast in a slurry trench. The trench excavation is initially supported by either Bentonite or polymer based slurries that prevent soil incursions into the excavated trench. The term "diaphragm walls" refers to the final condition when the slurry is replaced by tremied concrete that acts as a structural system either for temporary excavation support or as part of the permanent structure. The term slurry/cut-off wall is also applied to walls that are used as flow barriers (mainly in waste containment), by providing a low permeability barrier to contaminant transport.
Differential settlementThe vertical displacement due to settlement of one point in a foundation with respect to another point of the foundation.
Digital sensors with outputs including RS485 allows up to 32 sensors to communicate through one single data line. This linking together is known as BUS or often referred to as 'daisy chaining'.
Direct strainThe ratio of the change in length to the original length of a soil mass.
DowndragNegative skin friction. Forces induced on deep foundations resulting from downward movement of adjacent soil relative to the foundation element.
Drained loadingLoading which is slow enough for the water to drain from the soil as the total stresses increase. Pore pressure will not change, and volume will with loading.
DrawdownThe magnitude of the lowering of a water table by a system of dewatering which may include wellpoints, shallow or deep wells.
Dry densityThe ratio of the mass of the solids (soil grains) to the total unit volume of soil. Units: lbm/ft³, kg/m³.
Dry unit weightThe weight of solids (soil grains) to the total unit volume of soil. Units lb/ft³, kN/m³.
Dynamic compactionThe use of high-energy impact to increase the density of loose granular soils