Civil Engineering Technical Terms and Meaning - For E to I

For ‘E’

EASEMENT: The right to use or control the property of another for designated purposes.

ECCENTRIC LOAD: A load on a column applied at a point away from the column center and therefore putting a bending movement on the column equal in amount to the load multiplied by the arm.

EFFICIENCY: It is the power output divided by the power input.

ELASTOMER: Elastic rubber like substance, neoprene, etc.

EMBANKMENT: A ridge of earth or rock placed, shaped and compacted to carry a road, railway, canal, etc., or to contain water.

EMPIRICAL FORMULA: A formula or rule based on one or many series of observations or trials, but with no theoretical calculation.

EMULSION: A mixture with water. Asphalt emulsions are produced by adding a small amount of emulsifying soap to asphalt cement and water. When the water evaporates, the asphalt sets.

ENCROACHMENT: The use of the highway right-of-way for non-highway structures or other purposes.

ENERGY: A capacity for doing work, expressed in work units. Energy may be inherent in the speed of a body (Kinetic energy) or in its position relative to another body (Potential energy).

ENGINEER: The State (Client) Representative Engineer, acting by and under the authority of the laws of the State (Client). The Engineer is responsible for the Engineering monitoring and checking of construction work progress and conformance to the project specifications requirements.

ENGINEERING: The science through which the properties of matter and the sources of power are utilized for man's benefit.

EPOXIDE, EPOXY, ETHOXYLENE RESIN: A synthetic, usually two-part material that can set and harden under water or be used for bonding roof bolts or for repairing concrete in heavily trafficked areas, etc.

EROSION: Wearing or scouring caused by the abrasive action of moving water or wind.

ERRATIC: Values which seem to vary excessively from the average.

ERROR: A difference from an average value. An unintentional deviation from correct value.

EXPANSION OR CONTRACTION JOINT: A gap or space in the steel or the concrete to accommodate both thermal expansion and contraction.

EXPRESSWAY: A divided arterial highway for through traffic with full or partial control of access.

EXTRAPOLATE: To project tested values, assuming a continuity of an established pattern.

EXTRA WORK: Additional construction work for which no price or compensation is provided for in the contract and for which the Contractor is not deemed liable under any other provision of the contract, but found by the Engineer to be necessary or desirable for the satisfactory completion of the contract.

EXTRUSION: Forming rods, tubes, or sections of specified shape by pushing hot or cold metal or plastics through a shaped die to the required section.

For ‘F’

FACTOR OF SAFETY: The stress at which failure is expected, divided by the design stress (maximum permissible stress).

FALSEWORK: Support for concrete formwork or for an arch during construction.

FATIGUE: The lowering of the breaking-load of a member by repeated reversals of stress so that the member fails at a much lower stress than it can withstand under static loading.

FAULTING: The difference in elevation of two adjacent concrete slabs at a joint, primarily caused by the traffic-induced movement of base material particles from under one joint edge to under the adjacent joint edge.

FILL: Earthwork in embankment or backfilling.

FILLET: 3 to 6 inches wide chamfer for column to add beauty and strength by avoiding sharp angels.

FILLET WELD: A weld of roughly triangular cross-section between two pieces at right angles.

FINE AGGREGATE: (1) Sand or grit for concrete which passes the No. 4 sieve (4.76 mm) and retained in the No. 200 sieve (74 micron or 0.074 mm). (2) Sand or grit for bituminous road-making which passes a sieve of 3 mm square opening.

FIXED COSTS: Any necessary labor, material and equipment costs, directly expended on the item or items under consideration which remain constant regardless of the quantity of the work done.

FLAKING: Peeling off of the coating.

FLEXIBLE PAVEMENT: An asphaltic pavement structure having sufficiently low bending resistance to maintain intimate contact with the underlying structure, yet having the required stability furnished by aggregate interlock, internal friction between particles and cohesion to support traffic.

FLEXURE: Word meaning bending.

FLUME: A wooden, steel or concrete open channel to carry or measure water flows.

FLY-ASH: The ash which goes to the chimney from pulverized coal and is caught in the flue gas dust extractors. It is used as pozzolan or as an admixture to cement.

FORCE: That which tends to accelerate a body or change its movement (e.g., the weight of a body is a force which tends to move it downwards).

FORMATION LEVEL: The surface level or elevation of the ground surface after all digging and filling, but before concreting.

FORMWORK: The wood molds used to hold concrete during the placement and curing processes.

FOUNDATION FAILURE: Foundations of buildings can fail in one of two ways, first by differential settlement, secondly by shear failure of the soil.

FREEWAY: A divided arterial highway with full control of access.

FRONTAGE ROAD: A local street or road auxiliary to, and located on the side of an arterial highway for service to an abutting property and adjacent areas, and for control of access.

FROST: Weather during which dew is deposited as ice. The danger to construction caused by frost is that water expands by about 9% of its volume when it freezes. Therefore concrete or mortar which has not set and contains free water is disintegrated by it.

FUSION WELDING: The welding of metals or plastics by any method which involves melting of the edges of the parts to be joined without pressure. Usually a filler rod provides the weld metal.

For ‘G’

GABIONS: Compartmented rectangular containers made of galvanized hexagonal steel wire mesh and filled with stone. Gabions are used to stabilize and protect embankment slopes from erosion.

GANTRY: (1) A temporary staging for carrying heavy loads, such as earth. (2) overhead structure that supports signs, usually built of square timbers or steel joists.

GEOSYNTHETICS (GEOMATRIX, GEOMEMBRANE AND GEOTEXTILE): Thin fabrics membranes and composites placed between soil layers to prevent sliding and for reinforcing or to retard the migration of clay into the pavement structure or placed between pavement layers for reinforcing or to retard crack propagation from an underlying layer to the one above it.

GIRDER: A large beam, usually of steel or concrete. Its chords are parallel or nearly so, unlike a truss.

GORE: The V (Triangular) shaped area immediately beyond the divergence of two roadways bounded by the edges of those roadways.

GRANULAR: Material that does not contain more than 35 percent of soil particles which will pass a No. 200 sieve.

GRADING: Shaping and levelling the ground surface, usually by earth-moving equipments such as graders.

GRADIENT OR GRADE: The rise or fall per unit horizontal length (Slope) of a pipe, road, railway, flume, etc. Slope also expressed as the number of degrees from the horizontal or as a percentage.

GRAVEL: Granular material retained on a No. 4 sieve (4.76 mm) which is the result of natural disintegration of rock, or untreated or only slightly washed, rounded, natural aggregate, larger than 5 mm.

GRID: Any rectangular layout of straight lines (Generally used in locating points on a plan).

GRILLAGE: A footing or part of a footing consisting of horizontally laid timbers or steel beams.

GROOVING: The process of producing grooves in a concrete pavement surface to improve frictional characteristics.

GROUNDWATER: Water contained in the soil or rocks below the water table. Water table if lowered too much, the ground may settle disastrously.

GROUNDWATER LOWERING: Lowering the level of groundwater is to ensure a dry excavation in sand or gravel or to enable the sides of the excavation to stand up. Groundwater lowering in this sense is always carried out from outside the excavation either by well-points or from filter wells.

GROUT: (1) To fill with grout. (2) Fluid or semi-fluid cement slurry or slurry made with other materials for pouring into the joints of brickwork or masonry or for injection into the ground or pre-stressing ducts. Grouting of ducts improves the bond and may reduce corrosion of the tendons but it prevents their inspection and re-tensioning or renewal.

GUNITE, SHOTCRETE: A cement-sand mortar, thrown on to formwork or walls or rock by a compressed-air ejector, which forms a very dense, high-strength concrete. It is used for repairing concrete surfaces, making the circular walls of preload tanks, protecting wearing surfaces of coal bunkers; covering the walls of mine airways or water tunnels, stabilizing earth excavation slopes and so on.

GULLEY: (1) A pit in the gutter by the side of a road. It is covered with a grating. (2) A small grating and inlet to a drain to receive rainwater and wastewater from sinks, baths or basins.

For ‘H’

HEAVE: Upward movement of soil caused by expansion or displacement resulting from phenomena such as moisture absorption, removal of overburden, driving of piles, frost action, etc.

HEDGE: A row of closely planted shrubs forming a fence.

HIGHWAY: The whole right of way or area which is reserved and secured for use in constructing the roadway and its appurtenances.

HONEYCOMBING: Local voids or roughness of the face of a concrete structure, caused by the concrete having segregated so badly that there is very little sand to fill the gaps between the stones at this point. Such concrete is weak and should be cut out in a rectangular or square shapes and rebuilt if the wall is heavily loaded.

HYDRATION: The combination of water with any substance such as lime or minerals, which is responsible for the alteration of minerals in weathering; the formation of hydrated lime; the setting of cement and so on.

HVEEM'S RESISTANCE VALUE TEST (The R-Value): The R-value is a measure of the ability of a soil to resist lateral deformation when a vertical load acts upon it. The R-value ranges from zero (the resistance of water) to 100 (the approximate resistance of steel). R-values of soil and aggregate usually range from 5 to 85.

For ‘I’

IMPERVIOUS: Resistant to movement of water; a description of relatively waterproof soils such as clays through which water percolates at about one millionth of the speed with which it passes through gravel.

INITIAL SETTING TIME: The time required before a concrete mix can carry a small load without sinking like a mud. This is after about one hour in warm weather.

INHERENT SETTLEMENT: The sinking of a foundation due only to the loads which it puts on the soil below it and not to the loads on any nearby foundations. In city sites where the foundations are on clay, all foundations suffer both inherent and interference settlement.

INTERFERENCE SETTLEMENT: The sinking of a foundation due to loads on foundations near it and the natural extension of their settlement craters beyond their own boundaries.

INTERPOLATION: (1) Inferring the position of a point between known points on a graph by assuming that the variation between them is smooth. Usually the assumption is that the variation is linear (A straight-line variation). (2) To estimate untested values which fall between tested values.

INVERT LEVEL: The level of the lowest part of a pipe invert.
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