1 Flashcards
joist
One of a series of small, closely spaced beams used to support floor, ceiling, or roof loads.
statically indeterminate
Describing a structure whose reactions cannot be found from the equations of equilibrium only, but requires additional equations. Examples are continuous beams, fixed end beams, and most rigid frames.
reinforced brick masonry
A type of wall construction consisting of brick units, usually two tiers, with a solidly grouted space between each in which vertical and horizontal reinforcing bars are placed.
seismic separation
The separation between two adjoining buildings, or parts of the same building, to permit these adjoining elements to move independently when subject to earthquake motion. The amount of separation should be sufficient to prevent the adjoining elements from battering each other during an earthquake. Also called building separation.
single-shear
Describing a bolted joint which has one shearing plane through the bolts.
psi
An abbreviation for pounds per square inch.
wind bent
A frame used to resist lateral forces from wind.
fault
The boundary between adjacent rock plates along which movement may take place during an earthquake, such as the San Andreas fault in California.
aftershocks
Earthquakes following the occurrence of a large earthquake, or main shock. The magnitude of an aftershock is usually less than that of the main shock.
seismograph
An instrument which makes a continuous permanent record of earth motion, called a seismogram.
ca and cv
Seismic coefficients based on the building’s seismic zone factor and soil type.
open web steel joist
A shop-fabricated lightweight steel truss used to span between main members or bearing walls and support roof or floor loads.
camber
A curve built into a structural member to compensate for deflection.
pounding
The collision between two adjacent buildings which move differently during an earthquake.
drag strut
A member which collects seismic load from the diaphragm to which it is attached and delivers it to a shear resisting element. Also called a collector or strut.
yield point
The unit stress at which a material deforms with no increase in load.
stagnation pressure (qs)
The direct wind pressure on a vertical surface, in pounds per square foot.
tubular system
A structural system used in tall buildings, consisting of closely spaced columns at the perimeter connected by deep spandrel beams, which acts like a tube which cantilevers from the ground when subject to lateral wind or earthquake loads.
static lateral force procedure
A method of seismic design in which static horizontal forces which produce internal forces similar to those that would be induced by an actual earthquake motion are applied to a structure. This procedure is allowed only under certain conditions of building regularity, occupancy, and height.
bending moment
The algebraic sum of the moments of all forces that are on one side of a given cross-section of a beam.
mandrel
A solid core used in driving a shell pile into the ground. When the driving is complete, the mandrel is removed and the shell is filled with concrete.
plywood
A laminated panel of thin wood veneers, or plies, permanently bonded together with an adhesive. The grain of the adjacent plies is usually placed at right angles.
line of action
A line parallel to and aligned with a force.
modulus of elasticity (e)
Within the elastic limit, the constant ratio of the unit stress in a material to the corresponding unit strain. The modulus of elasticity of a material is a measure of its stiffness.
inelastic
Describing a material which does not return to its original size and shape when load is removed, but retains permanent deformation. Also describes structural behavior in which members are stressed above the yield point.
ultrasonic testing
Nondestructive testing of welded joints using high-frequency sound waves.
e
A symbol for modulus of elasticity.
positive moment
Bending moment which produces compression in the upper part of a beam and tension in the lower part.
pretensioning
A method of prestressing concrete in which the tensile force is put into high-strength steel wires before the concrete is cast.
moment distribution
A method for solving the bending moments in statically indeterminate structures, such as rigid frames and continuous beams, by successive approximation.
balloon framing
A method of framing wood stud walls, in which the studs are continuous for the full height of the building, which is usually two stories.
overhanging beam
A beam that rests on two or more supports and has one or both ends projecting beyond the support.
combined footing
A footing supporting two or more columns.
gunite
Pneumatically applied concrete shot into place by means of compressed air. This method may be used for both repair work and new construction, especially in difficult locations or where thin sections occur.
precast pile
A reinforced concrete pile cast in other than its final location. After curing, it is moved to its final location and driven into place. Precast piles are square, round, or octagonal, and are frequently prestressed.
expansive soil
A fine-grained cohesive soil which undergoes large volume changes with changes in moisture content.
force
A push or pull exerted on an object. The description of a force includes its magnitude, direction, and point of application.
stiffness
Resistance to deformation, also known as rigidity.
friction pile
A pile whose load is supported by friction between the pile surface and the surrounding soil.
rigidity
Resistance to deformation, also known as stiffness.
I
A symbol for moment of inertia.
tapered girder
A plate girder having a tapered profile, usually varying from minimum depth at the supports to maximum depth at midspan.
organic soil
Soil with a high organic content (decomposed vegetable or animal matter). Organic soils are usually very compressible and have very low bearing capacities.
flat slab
A concrete slab reinforced in two directions which brings its load directly to supporting columns without any beams or girders, usually requiring column capitals (widened tips of columns) and drop panels (thickened slab around columns).
engineering news formula
A dynamic formula used to determine the capacity of driven piles.
catenary
The curve assumed by a cable hung between two supports, when the only load acting on it is its own weight. The stresses in the cable are pure tension.
grout
A high-slump concrete, consisting of Portland cement, sand, hydrated lime, water, and sometimes pea gravel.
two-way concrete slab
A concrete slab in which the main reinforcement runs in two directions, generally perpendicular to each other.
stud wall
A wall consisting of small, closely spaced members usually sheathed on both faces with a wall material.
trowel finish
A smooth dense concrete surface, produced by steel troweling after the concrete has partially hardened.
bleeding
The movement of water to the surface of freshly cast concrete.
v
A symbol for either base shear or vertical shear.
nonbearing wall
A wall which supports no vertical load other than its own weight.
ksi
An abbreviation for kips per square inch.
dead load
The vertical load due to the weight of all permanent structural and nonstructural components of a building, such as walls, floors, roofs, and fixed service equipment.
hurricane
A severe tropical storm which occurs mainly along the coasts of the Gulf of Mexico and the South Atlantic. The design of buildings to resist wind in accordance with building code requirements includes the effects of hurricanes.
welding
A method of joining two pieces of metal by heating their surfaces until they are molten or plastic, with or without applying pressure, and with or without the use of additional filler material.
Portland cement
The finely ground material used as the binder for structural concrete.
structural slab
A wide, flat reinforced concrete member, usually horizontal, which is supported by beams or walls.
uniformly distributed load
A beam loading of constant magnitude per unit of length.
simple beam
A beam that rests on a support at each end.
sleeper
A horizontal wood member used to support a structure above, such as one of the wood strips between a concrete slab and a finished wood floor.
lumber
Wood that has been sawn into construction members.
active pressure
The pressure exerted by retained earth against a retaining wall.
kip
A unit of force or weight equal to 1000 pounds.
reinforced concrete block masonry
A type of wall construction consisting of hollow concrete masonry units, with certain cells continuously filled with grout in which reinforcing bars are embedded.
column footing
A spread footing, generally square or rectangular in plan, used to support a single column.
vibratory compactor
A machine used primarily for the compaction of granular soils, such as sands.
plate tectonics
The theory which explains earthquake phenomena.
importance factor (i)
A factor used in earthquake and wind design, whose value varies between 1.0 and 1.5. This provides that certain essential facilities, such as hospitals and fire and police stations, be designed for seismic and wind forces greater than normal. In this way, such emergency facilities are expected to be safe and usable following an earthquake or severe windstorm.
arc welding
The most usual welding process used in building construction, in which intense heat is produced by an electric arc between the members to be joined and a metal wire or rod, called the electrode.
end-bearing pile
A pile whose load is supported by firm soil or rock under the pile tip.
reinforced concrete
Concrete containing adequate reinforcing steel and designed on the basis that the concrete and steel act together in resisting forces. The concrete is usually assumed to resist compression, while the reinforcing steel is assumed to resist tension.
belled caisson
An end-bearing pile constructed by pouring concrete into a drilled shaft, the bottom of which is enlarged (belled) to provide a larger bearing area.
cylinder test
A test to determine the compressive strength of concrete by subjecting a standard cylinder of hardened concrete to compression in a testing machine.
impact load
The sudden application of load from a moving object, such as a crane or elevator, which causes stresses much greater than those caused by a static load.
period (t)
The time it takes for a structure to go through one complete back-and-forth motion under the action of dynamic loads. Also called fundamental period of vibration or natural period.
test boring
A hole drilled into the ground at the site of a proposed structure in order to obtain samples of the subsurface soil for examination and testing in a laboratory. Based on these tests, the soils engineer recommends the type of foundation and the allowable soil bearing pressure.
tributary area
The floor or roof area supported by an individual structural member.
Richter scale
A logarithmic scale used to measure the magnitude of an earthquake (the amount of energy it releases). The largest earthquake ever recorded had a magnitude of about 8.9. The scale is named after its inventor, Dr. Charles Richter.
tsunami
An ocean wave produced by displacements of the ocean bottom as the result of an earthquake or volcanic activity.
building separation
The separation between two adjoining buildings, or parts of the same building, to permit these adjoining elements to move independently when subject to earthquake motion. The amount of separation should be sufficient to prevent the adjoining elements from battering each other during an earthquake. Also called seismic separation.
pile hammer
A hammer used to drive piles into the ground. Pile hammers may drop by gravity, or may be operated by steam or compressed air.
dome
A roof structure whose shape is that of an arch rotated about its vertical axis to form a curved surface.
welded wire fabric
A type of reinforcement used in reinforced concrete, consisting of a grid of steel wires perpendicular to each other and welded at all points of intersection.
counterfort wall
A retaining wall in which the stem and base are connected at intervals by transverse walls called counterforts.
wood screw
A threaded metal fastener with a pointed end which forms its own matching thread in the wood member into which it is inserted.
air-supported structure
A member enclosing a pressurized occupied space, which must be held down to its foundation.
water table
The level below which the subsoil is completely saturated with water. Also called the groundwater level.
windward side
The side of a building facing the direction from which the wind is blowing.
tornado
A localized, violently destructive windstorm characterized by a long funnel-shaped cloud. Building code requirements for wind design do not usually include the effects of tornadoes.
liquefaction
Transformation of soil into a liquefied state, similar to quicksand, as a result of earthquake vibrations.
gabled frame
A frame consisting of two columns and two inclined beams which meet at the ridge, in which the joint between each column and beam is rigid.
fillet weld
A weld placed in the right angle formed by lapping or intersecting plates and generally subject to shear stress.
bearing wall system
In seismic design, a structural system without a complete load-carrying frame. Gravity loads are resisted by bearing walls or bracing systems, and lateral loads are resisted by shear walls or braced frames. Bearing wall systems are designed for relatively high seismic forces.
platform framing
A method of framing wood stud walls in which the studs are one story in height and the floor joists bear on the top plates of the wall below.
bearing pile
A pile which supports a vertical load.
live load
The vertical load caused by the use and occupancy of a building, not including wind, earthquake, or dead loads.
wall footing
A continuous spread footing supporting a uniformly loaded wall.
control joint
A groove in a concrete structure made to predetermine the location of cracks.
