STRUCTURAL SYSTEMS (spd) Flashcards
properties of sections
1 area 2 centroid 3 statical moment 4 moment of inertia 5 section modulus 6 radius of gyration (ss)
The rate of changes of velocity, usually expressed a fraction of percentage of g, the acceleration of gravity.
acceleration(ss)
A substance, such as calcium chloride, added to a concrete mix to speed up its setting and strength development.
accelerator(ss)
A seismological instrument which is normally inoperative, but becomes activated when subject to strong earth motion, records the earth motion, and then shut off.
accelerograph(ss)
The pressure exerted by retained earth against retaining wall.
active pressure(ss)
A prepared substance added to concrete to alter or achieve certain characteristics.
admixture(ss)
Earthquake following the occurrence of a large earthquake, or main shock. The magnitude of an aftershock is usually less than that of the main shock.
Aftershock(ss)
The chemically inert element of concrete, usually consisting of sand, gravel, and/or other granular material.
aggregate(ss)
The incorporation of tiny air bubbles into concrete to improve its workability and resistance to frost.
air entrainment(ss)
A membrane enclosing a pressurized occupied space, which must be held down to its foundation.
air-supported structure(ss)
The maximum units of stress permissible in a structural member. It is called working stress
allowable stress(ss)
An increase in a building’s reponse to earthquake ground motion, resulting from the building’s period coinciding with that of the ground shaking, or other causes.
amplification(ss)
A device used to measure wind speed.
anemometer(ss)
The steepest angle with the horizontal at which a pile of loose earth will stand without sliding.
angle of repose(ss)
The most usual welding process used in building construction.In which intense heat is produce by an electric arc between the numbers to be joined and a metal wire or rod, called electrode
arc welding(ss)
A curve structure in which the internal stresses are essentially compression.
arch(ss)
The arbitrary limits which define the boundaries between the different states of rigidity or fluidity of fine-grained soils.
Atterberg limits (ss)
A longitudinal load which acts at the centroid of a member and perpendicular to its cross-section, thereby producing uniform tensile or compressive stress without any bending.
axial load (ss)
Reinforced concrete design in which there is simultaneous crushing of concrete and yielding of the reinforcing steel. To assure that yielding of the steel occurs before crushing of the concrete, the amount of reinforcing is limited to 75 percent of that which would produce a balanced design.
balanced design (ss)
The total design lateral force or shear at the base of a structure.
base shear (v) (ss)
The fastest mile wind speed which has a 2 percent probability of occurring in any one year measured at a point 33 feet (10 meters) above ground
basic wind speed (ss)
Reference points offset a given distance from the building line and set prior to excavation
batter boards (ss)
A structural member which supports loads perpendicular to its longitudinal axis.
beam (ss)
the load per unit area which can be safely support by the ground.
bearing capacity (ss)
A pile which supports a vertical load.
bearing pile (ss)
A wall which supports any vertical load in addition to its own weight.
bearing wall (ss)
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.
bearing wall systems (ss)
A structural steel connection using high-strength bolts, in which some slip can occur and bearing stresses are considered.
bearing-type connection (ss)
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.
belled caisson (ss)
The algebraic sum of the moments of all forces that are one side of a given cross-section of a beam
bending moment (ss)
The movement of water to the surface of freshly cast concrete
bleeding (ss)
A horizontal reinforced masonry beam, usuallt built integrally with a masonry wall.
bond beam (ss)
most common sub surface exploration.
boring , test pit (ss)
A vertical truss used to resist lateral forces
braced frame (ss)
Cross braces used between joist to stabilize them
bridging(ss)
Describing a material or structural system which tends to fail suddenly without warning when subject to high stresses, as opposed to a ductile material or system, which can absorb energy without failure
brittle
To crush and spread the head of a wood file by driving with a hammer.
broom
In seismic design, a structural system with and essential complete frame providing support for gravity loads.Lateral loads are resisted by shear wall or braced frames. Building frame systems are designed for seismic forces which are lower than those for bearing wall systems.
building frame system
Seismic coefficient based on the building’s seismic zone factor and soil type.
ca & cv
A curve structure in which the internal stresses are pure tension.
cable roof
A waterproof box-like structure in which construction work can be performed underwater. Also a pile constructed by pouring concrete into a drilled shaft
caisson
The most common accelerating admixture used for concrete.It can be used safely in amount up to 2 percent of Portland cement weight.
calcium chloride
A ratio used to determine the bearing capacity of a soil, based on a standard test.
California bearing ratio (CBR)
A beam that is restrained against rotation at one end and free at the other.
cantilever beam
An exterior column footing joined by a concrete beam to an interior column footing. It is also called a strap footing.
cantilever footing
A retaining wall in which the stem heel, and toe act as cantilever slabs
cantilever wall
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
catenary
The combined height, exposure, and gust factor used in wind design.
ce
The point in a cross-section where all of the area may be considered concentrated without affecting the moment of the are about any axis. For symmetrical shapes, the centroid is the geometric center of the shape.
centroid
A type of diagonal bracing in which one end of each brace frames into a beam-column joint and other frames into a beam. There are two configurations.V-bracing and inverted-V- bracing.Because of various potential problems with chevron bracing the bracing members must be designed for increased seismic loads.
chevron bracing
compose of smaller particle that have some cohesion or tensile strength, and are plastic in behavior.
clay
four groups of soil
clay silt organic sand & gravel
A group of piles
cluster
whose line of action all lies with the same plane.
co planar forces
The ratio of the maximum frictional force between two bodies to the normal (perpendicular) for pressing the surfaces together.
coefficient of friction
The ratio of unit to temperature change, which is constant for a given material.
coefficient of the thermal expansion
A joint formed when a concrete surface hardens before the next batch is placed against it.
cold joint
A horizontal tie beam connecting two opposing rafter at a level above the wall plates.
collar beam
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 strut or drug strut.
collector
those whose vectors lies along the same straight line
collinear forces
A footing supporting two or more columns.
combined footing
One of two or more forces which will produce the same effect on a body as a given force.
component
A steel beam and concrete slab connected so that they act together as a single structural unit to resist bending stresses.
composite beam
Steel floor decking with embossed ridges, bonded to a concrete slab so that they act together as a single structural unit.
composite deck
Stress in which the particle are pushed together and the member tends to shorten
compression
Caused material to shorten and widen
compressive force
Reinforcing steel embedded in the compression face of a reinforced concrete beam.
compressive reinforcement
A load which acts at one point on a structure.
concentrated load
A braced frame in which the center lines of intersecting members meet at a point and whose members are therefore subjected primarily to axial forces.
concentric braced frame
Describing the condition when the lines of action of several forces pass through a common point
concurrent
whose lines of action meet at a common point.
concurrent forces
The joint between two successive concrete pours. Construction joints are usually located where the shear is minimum, such as at the midspan of beams.
construction joint
A groove in a concrete structure made to predetermine the location of cracks.
control joint
A compression test of hardened concrete which has been cut from the structure.
core test
Two forces equal in magnitude,but opposite in direction, and acting at some distance from each other.The moment produced by a couple is equal to the value of one force multiplied by the distance between the two forces.
couple
In wind design, a pressure coefficient for the structure or portion of the structure under consideration.
cq
Continued deformation of a structural member with time, with no increase of load.
creep
Maintaining concrete at the proper moisture and temperature after it is cast.
curing
A factor used to modify the allowable stress in bending for the curved portion of glued laminated members.
curvature factor
The decrease of vibration caused by the absorption of energy.Building contain a number of elements,both structural and nonstructural,which absorb energy during an earthquake and thereby diminish the earthquake-induced vibration.
damping
The movement of a beam from its original location when load is applied to it
deflection
The change in size of a body caused by external forces. It is also called strain.
deformation
The separation of lamination of a glued laminated beam caused by failure of adhesive.
delamination
First steps in designing a foundation .
determine the bearing capacity of underlying soil.
A horizontal system which distributes lateral forces, caused by wind or earthquake, to the vertical resisting elements
diaphragm
The boundary element of a diaphragm or shear wall which is assumed to resist axial stresses, analogous to a flange of a beam.
diaphragm chord
Unequal settlement of the various parts of a building, which may cause excessive stresses in the structural frame or tilting of the building
differential settlement
Horizontal or vertical movement of a structural element resulting from applied seismic or other load.
displacement
Describing a bolted joint which has two shearing planes through the bolts.
double-shear
A member which collects a seismic load from diaphragm to which it is attached and delivers it to a shear resisting element. also called a collector or strut.
drag strut
The horizontal movement of a structure when subject to wind or earthquake forces.
drift
An end-bearing pile, the bottom of which may be belled, which is constructed by pouring concrete into a drilled shaft.
drilled caisson
A vertical shaft drilled into the ground and filled with concentrate, which supports building loads by skin friction.
drilled pile
In seismic design, a combination of moment resisting frames and shear walls or braced frames
dual systems
The ability of a material to undergo large deformations without fracture.
ductility
A method for determining earthquake forces in which a mathematical model of the structure is develop and then subjected to appropriate ground motions. This procedure is always accepted for design.
dynamic lateral force procedure
A braced frame in which at least one end of which brace is eccentric to the beam-column joint or the opposing brace. The intent is to make the braced frame more ductile and therefore able to absorb a significant amount of energy without buckling the braces.
eccentric braced frame (EBF)
A longitudinal load which acts at a distance from a member’s centroid, thereby producing bending moment in addition to axial stress.
eccentric load
In reinforced concrete design, the distance from the extreme compression fiber to the centroid of the tension reinforcement.
effective depth (d)
The material will begin to change length at a faster ratio than the applied force
elastic limit
The unit stress for a material, below which Hooke’s Law applies.
elastic limit
A pile whose load is supported by firm soil or rock under the pile tip.
end-bearing pile
A dynamic formula used to determine the capacity of driven piles.
engineering news formula
The projection of the focus, where rock slippage begins, on the ground surface
epicenter
A force equal in magnitude to the resultant, but opposite in direction and on the same line of action as the resultant.
equilibrant
Is said to exist when the resultant of any number of forces acting on a body is zero
equilibrium
Structures or buildings which must be safe and usable for emergency purposes after an earthquake or severe windstorm. Such facilities include hospitals and fire and police stations.
essential facilities
A basic equation which applies to all columns and gives the maximum stress a slender column can resist without failing by sudden buckling.
Euler’s equation
A fine grained cohesive soil which undergoes a large volume changes in moisture content.
expansive soil
The ratio of the ultimate strength of a material to its working stress.
factor of safety
The Boundary between adjacent rock plates along which movements may take place during an earthquake, such as the San Andreas Fault in California.
Fault
The location that is restrained(fixed) against rotation at both ends.
fixed end beam
A concrete slab reinforced in two directions which brings its load directly to supporting columns without any beams, girders, column capitals (widened tops of columns), or drop panels (thickened slab around columns)
flat plate
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 tops of columns) and drop panels (thickened slab around columns).
flat slab
Another term for bending.
flexure
A structural roof system consisting of inclined planes which support each other and function as deep beams.
folded plate
A foundation which spreads the load over a large area of soil. It is also called a spread footing
footing
A push or pull exerted on an object. The description of a force includes its magnitude ,direction, and point of application.
force
Any action applied to an object.
force
A diagram used to graphically determine the resultant of two or more forces.
force polygon
The part of a building s load to the underlying soil.
foundation
A metal device used for connection members in wood frame construction.
framing anchor
A diagram obtained by making an imaginary cut through a structure and applying the equation of equilibrium to the remaining portion, called the “free body.”By this means, the internal forces of a structure may be determined.
free body diagram
Referring to soil which is easily crumbled or reduced to powder.
friable
Uplift of the soil surface or foundation caused by freezing of moisture in the soil.
Frost heave
The time it takes for a structure to go through one complete back-and-forth motion under the action of dynamic loads. also called period or natural period.
fundamental period of vibration (t)
A main beam which supports secondary beams.
girder
A framework if horizontal member used to spread a structural load over a large area.
grillage
A weld placed between two butting pieced of metal to be joined.
groove weld
The principal cause of structural damage, injury and loss of life during an earthquake. The provisions of the Uniform Building Code provides resistance to earthquake ground shaking, without settlement, slides, subsidence, or faulting in the immediate vicinity of the structures.
ground shaking
A high-slump concrete, consisting of Portland cement, sand, hydrated lime, water and sometimes pea gravel.
grout
A pneumatic applied concrete shot into place by means of compresses air. this method may be used for both repair work and new construction especially in difficult locations or where the section occur.
gunite
Referring to construction in which fire resistance is obtained by using wood structural members of specified minimum sizes
heavy timber
A type of cement (ASTM type lll) which provide earlier strength in concrete than ordinary cements. It is used when form must be removed quickly or when the structure must be put into service quickly.
high-early-strength-concrete
The deformation (strain) is directly proportional to the stress, up to a certain point.
Hooke’s Law
The physical law that states that up to a certain unit stress, called the elastic limit, unit stress is directly proportional to unit strain
Hooke’s Law
A horizontal member which extends around the circumference of a dome.
hoop
A horizontal truss system which distributes lateral forces, caused by wind or earthquake, to the vertical resisting elements.
horizontal bracing system
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.
hurricane
The chemical reaction which combines cement and water to form a hard, solid mass
hydration
The pressure exerted by a liquid against every surface it contacts.
hydrostatic pressure
A thin shell saddle-shaped surface formed by moving a vertical parabola with downward curvature along and perpendicular to another parabola with upward curvature.
hyperbolic paraboloid
The location in the earth’s crust where rock slippage begin during an earthquake. Also called the focus.
hypocenter
A symbol for moment of inertia
I
A nondestructive test to determine the strength of hardened concrete, by measuring the rebound of a plunger after striking the concrete surface. This test is not accurate enough to be substitute for standard compression tests.
impact hammer test
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.
impact load
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 design for seismic and wind forces greater than normal. In this way, such emergency faclities are expected to be safe and usable following an earthquake or severe windstorm.
importance factor (i)
Describing a material which does not return to its original size and shape when the load is removed, but retain permanent deformation. also describes structural behavior in which member are stressed above the yield point.
inelastic
The effect of an earthquake on people and structures at a particular place, as measured by the Modified Mercalli scale,Intensity refers to an earthquake’s effect,while magnitude refers to an earthquake’s energy.
intensity
Map contour connecting points of equal intensity for a given earthquake.
isoseismals
A short rafter between hip rafter and eave or between valley and ridge.
jack rafter
A method of placing piles using high-pressure water jets.
jetting
A shop fabricated steel truss that supports evenly-spaced steel joist along its top chord.
joist girder
An effective length factor used in the design of structural steel columns.
K
A test to determine the workability of fresh concrete.
Kelly ball test
A lower layer of fine particle that floats to the surface of wet concrete.
laitance
A roof structure comprising a series of parallel arches, skewed to the axes of the building, which are intersected by another series of skewed arches, so that they interact with each other
lamella
The part of the structural system assigned to resist lateral forces from wind or earthquake.
lateral force resisting system
Any horizontal load on a building,including the load from wind or earthquake.
lateral load
A horizontal member supporting joists.
ledger
A flat plate cast at grade around columns and then lifted to position with hydraulic jacks.
lift slab
A line parallel to and aligned with force.
line of action
In seismic design ,the content at which the soil starts to change from plastic to semi liquid state.
liquid limit
The vertical load caused by the use and occupancy of a building not including wind, earthquake, or dead loads.
live load
A force applied to a body.
load
Wood has been sawn into construction members.
lumber
A symbol for bending moment.
M
The amount of energy released by an earthquake,as measures=d by the Richter scale.Magnitude refers to an earthquake’s energy, while intensity refers to an earthquake’s effects.
magnitude
A solid core is used in driving a shell pile into the ground. When the driving is complete, the mandrel is removed and the shell if filled with concrete.
mandrel
In concrete, the cement past in which the aggregate particles are embedded
matrix
The stress diagram used in the graphical solution of a truss, which consist of the combined force polygons for all the truss joints.
Maxwell Diagram
A curve line on the surface of a dome, usually circular, which is formed by the intersection of a vertical plane with the dome, when the plane passes through the top of the dome.
meridian
A wind method in which the wind pressures are assumed to act simultaneously normal (perpendicular) to all exterior surface.
Method 1 (normal force method)
A wind design method in which horizontal pressure are assumed to act on the full vertical projected area of the structure, and the vertical pressures are assumed to act simultaneously on the full horizontal projected area.
Method 2(projected area method)
An analytical method for determining the force in the members of a truss, in which the truss is cut by an imaginary section and a free body diagram drawn of the portion of the truss thus isolated.
method of sections
A scale used to measure the intensity of an earthquake, that is, its effect in people and buildings. The scale varies from I (not felt except under especially favorable circumstances) to Xll (damage nearly total).
Modified Mercalli scale
characteristic ratio of steel to strain of material
modulus of elasticity
With in 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.
modulus of elasticity (e)
The unit bending stress calculated from the flexure formula, for the maximum bending moment resisted by a beam before rupture
modulus of rupture
The tendency of a force to cause rotation about a given point or axis
moment
A graphic representation of the value of the bending moment at any point along a beam.
moment diagram
A method for solving for the bending moments in statically indeterminate structures, such as rigid frames and continuous beams, by successive approximation.
moment distribution
The sum of the products obtained by multiplying each unit of area by the square of its distance to the neutral axis. Moment of inertia of a beam is a measure of its stiffness, or resistance to deflection.
moment of inertia (l)
In seismic design, a structural system with an essentially complete frame which provides support for vertical loads. Lateral loads are resisted by moment-resisting frames.
moment-resisting frame system
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 period.
natural period (t)
A short beam passed through a wall to provide temporary support.
Needle Beam
Bending moment which produces tensions in the upper part of the beam and compression in the lower part.
negative moment
The line on a beam cross-section which has zero bending stress when the beam is loaded.
neutral axis
the line of cation do not pass through a common point
non concurrent forces
Concrete made with standard aggregates, usually weighing about 150 pounds per cubic foot.
normal weight concrete
A shop-fabricated lightweight steel truss used to span between main members or bearing walls and support roof or floor loads.
open web steel joist
Materials with vegetation or other organic matter.
Organic soil
Soil with a high organic content (decomposed vegetable or animal matter).Organic soil are low usually very compressible and have very low bearing capacities.
organic soil
A beam that resists on two or more supports and has one or both ends projecting beyond the support.
overhanging beam
The moment, caused by wind or earthquake, which tends to overturn a structure.
overturning moment
The resistance to the movement of a retaining wall provided by the earth in front of the wall and its footing
passive pressure
The secondary effect on frame members produced by vertical loads acting on a building frame which is laterally displaced by earthquake loads.
p-delta effect
A test to verify or determine the allowable pile loads used in design.
pile load test
The moisture content at which a soil starts to change from a semisolid to a plastic state.
plastic limit
A assembly of steel plates, or plates and angles, which are fastened together to form an integral member.
plate girder
The point in a beam or other flexural member where the bending moment changes signs and has a value of zero.
Point of inflection
The finely ground material used as the binder for structural concrete .
Portland Cement
Bending moment which produces compression in the upper part of a beam and tension in the lower part.
positive moment
The collision between two adjacent buildings which move differently during an earthquake
pounding
A reinforced concrete pile cast in other than its final location.After curring, it is move to its final location, and driven into place. Precast piles are square, round, or octagonal, and are frequently pre-stressed.
precast pile
Concrete which is permanently loaded so as to cause stresses opposite in direction from those caused by dead and live loads
pre-stressed concrete
A method of pre-stressing concrete in which the tensile force is put into high-strength steel wires before the concrete is cast.
pre-tensioning
A laboratory compaction test to determine the optimum moisture content and density for a soil.
Proctor Test
A regularly spaced roof beam which spans between girder or trusses.
purlin
Nondestructive testing of welded joints using x-rays and gamma rays.
radio-graphic inspection
A large footing under an entire building, which distributes the building load over the entire area. It is also known as a mat foundation.
raft foundation
3 forces acting on the section
reaction on support , tensile forces in the bottom , compressive on top
Any truss member not necessary for stability.
redundant member
In seismic design, a structure which has no significant physical discontinuities in plan or vertical configuration or in its lateral force resisting system. Regular structures exhibit more favorable and predictable seismic response characteristics than irregular structures.
regular structure
A type of wall construction consisting of brick unit, usually tow tier,with solidly grouted space between each in which vertical and horizontal reinforcing bars are placed.
reinforced brick masonry
Replacing a force with two or more other forces (components) which will produce the same effect on a body as the original force
resolving forces
The condition that occurs when a building’s period is close to that of the predominant period of the earthquake ground shaking.Resonance causes the building’s response to be amplified and the resulting increases in the buildings earthquake-induced forces and deformations must be considered in the design.
resonance
The effect produced on a structure by earthquake ground moving
response
A curve which shows the maximum acceleration of a series of idealized structures when subject to an earthquake.
response spectrum
One force which will produce the same effects as two or more other forces.
resultant
A wall which resists the lateral pressure of retained earth or other material.
retaining wall
Resistance to deformation, also known as stiffness.
rigidity
A numerical coefficient used in seismic design which depends on the type of lateral force resisting system used,
rw or r
are granular material that are none-plastic
sand and gravel
ratio of the beams moment of inertia to the distance from the neutral axis to the outer most part of the section (extreme fiber)
section modulus
The ratio of the moment of inertia of a beam (i)to the distance from its neutral axis to the most remote fiber (c). Thus, section modulus (s) *l/c. The S-value of a beam is a measure of its ability to resist bending moment.
section modulus (s)
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.
seismic separation
A factor used in seismic design which depends on the seismic zone in which a site is located.
seismic zone factor (z)
A measure of the frequency,intensity, and distribution of earthquakes in a given area.
seismicity
Stress in which the particle a member slide pass each other
shear
A high-strength timber connector used in wood-to-steel connections (using one shear plates), where demountability is desired.
shear plate
A large-toothed roller used for the compaction of soil.
sheeps foot roller
Vertical members used to temporarily hold the face of an excavation during construction
sheeting
Are intermediate size between clay and sand and behave as granular materials but are sometimes slightly plastic in their behavior.
silt
A beam that rest on a support at each end.
simple beam
Describing a bolted joint which has one shearing plane through the bolts.
single-shear
A factor used to reduced the allowable bending stress for wood beams deeper than12 inches.
size factor
The friction between the surface of a file and the surrounding soil.
skin friction
A structural steel connection using high strength bolts, in which no slip can occur.
slip-critical connection
Is general describe term used to describe the material that supports a building.
soil
Has a highest bearing capacity of all the soil type.
solid rock
A series of truss which intersect in a consistent grid pattern and are rigidly connected at their points of intersection.
space frame
combination set of concurrent and non coplanar forces.
space frame
As used in earthquake design, a moment-resisting frame made of structural steel or reinforced concrete which has the ability to absorb a large amount of energy in the inelastic range, that is, when the material is stressed above its yield point, without failure deforming unacceptably
special moment-resisting frame (SMRF)
The direct wind pressure on a vertical surface, in pound per square foot.
stagnation pressure (qs)
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.
static lateral forces procedure
The product of an area and the distance from the centroid of the area to a given axis.
statical moment
Describing a structure whose reactions can be determined from the equations of equilibrium.Example are simple beams,cantilever beams, and overhanging beams that rest on two supports.
statically determinate
Describing a structure whose relations cannot be found from the equations of the equilibrium only, but requires additional equations. Example are continuous beams, fixed end beams, and most rigid frames.
statically indeterminate
Is a branch of mechanics that deals with bodies in a state of equilibrium
statics
Resistance to deformation, also known as rigidity.
stiffness
A vertical steel bar, usually U-shaped, used to reinforce a reinforced concrete beam where the shear stresses are excessive.
stirrup
The horizontal movement of one level of a building relative to the level immediately above or below, caused by wind and earthquake.
story drift
Is the deformation of material caused by external forces.
strain
The change in size of a body caused by external forces it is also called deformation.
strain
An exterior column footing joined by a concrete beam to an interior column footing. It is called a cantilever footing.
strap footing
The ability of material or structure to resist stresses
strength
The Method Generally used for reinforced concrete design, formerly called ultimate strength design.
Strength Design
A factor used to reduce the capacity of reinforced concrete members to account for possible variations in quality control.
strength reduction factor (O)
An internal force in a body which resists an external force.
stress
A graphical method for determining the forces in the members of a truss. It is also called a Maxwell diagram.
stress diagram
A wide,flat reinforcement concrete member, usually horizontal, which is supported by beams or walls.
structural slab
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 drag strut.
strut
A steel framing system in which beams sit on top of a girder and short lengths of “stub girders” the same depth as the floor beams are welded to the top of the girder to provide for composite action.
stub girder system
Negative pressure
suction
Increased earth pressure against a retaining wall caused by vertical load behind the wall or a sloping ground surface.
surcharge
A plate girder having a tapered profile, usually varying from minimum depth at the support to maximum depth at mid span.
tapered girder
A reinforced concrete beam consisting of a portion of the slab and the integrally constructed beam, which act together.
t-beam
Causes a rod to elongate and narrow
Tensile force
is the stress which the particle of the member tend to pull apart under load.
tension
Basic theory of bending
the internal resisting moment at any point in a beam must equal the bending moment produced by the external load in the beam.
A structure with a curve surface that supports load by tension, compression, and shear in the plane of its surface, but which is too thin to resist bending stresses.
thin shell
An arch with a hinge at each support and at the high point, or crown: the only type of arch which is statically determinate.
three-hinge arch
The horizontal reaction at the base of an arch.
thrust
A reinforced concrete column, usually square or rectangular, containing longitudinal reinforcing bars and separate lateral ties.
tied column
A high-strength connector used for wood-to-wood or wood- to-steel joints.Types include one split ring (wood-to-wood),two shear plates (wood-to-wood),and one shear plate (wood-to-steel).
timber connector
A pipe for placing concrete under water. A hopper for filling is provided at the top, while the lower and is kept submerged in fresh concrete.
tremie
The assumed distribution of earthquake forces to various levels of structure.
triangular distribution
the floor or roof area supported by an individual structural member
tributary area
collection of set of concurrent and coplanar forces
truss
A prefabricated, lightweight wood truss used to support roof loads and other small structures.
trussed rafter
A structural system used in tall buildings, consisting of closely spaced column at the perimeter connected by deep spandrel beam, which acts like a tube which cantilever from the ground when subject to lateral wind or earthquake loads.
tubular systems
A method used to provide the bolt tension specified for high-strength bolts, in which the bolts are first brought to a Snug Tight condition and then tightened additionally by a specified amount of nut rotation
turn-of-net method
Factor used to increase loads, shears, and moments to their ultimate values in reinforce concrete design.
ultimate load factor
The maximum unit stress that can be developed in a material
ultimate strength
when load is continually increased and before the material ultimately rupture.
ultimate strength of material
Non destructive testing of welded joints using high-frequency sound waves.
ultrasonic testing
Deepening an existing foundation or building. Underpinning is usually required when excavation for a new building is adjacent to and deeper than an existing foundation
underpinning
The most widely used system for classifying soils. In this system, the soils are primarily classed as coarse-grained(gravels and sands), fine grained(silts and clays), and highly organic.
Unified Soil Classification System
A beam loading of constant magnitude per unit of length.
uniformly distributed load
A symbol for either base shear or vertical shear.
v
A series of arches placed side-by-side to form a continuous structure.
vault
A light weight aggregate used in light weight concrete.
vermiculite
The algebraic sum of the forces that are on one side of a given cross-section of a beam.
vertical shear (v)
Consolidating freshly poured concrete by using an oscillating vibrator. Immersion-type (spud) vibrators are lowered into the concrete, while form vibrators are attached to the exterior of forms.
vibration
A machine used primarily for the compaction of granular soils,such as sands.
vibratory compactor
A truss with no diagonals.
vierendeel truss
A factor used to reduce the allowable bending stress for glued, laminated beams, based on width, depth and span.
volume factor
A continuous spread footing supporting a uniformly loaded wall.
wall footing
The ratio of water to cement in a concrete mix,the main factor which determines concrete strength.
water-cement ratio
A story whose strength is less than 80 percent of that of the story above. Such an abrupt change of strength should be avoided if possible.
weak story
The portion of a truss between the chords, or the portion of a beam in the flanges
web
The interior members of a truss, which connect the chords.
web members
A frame used to resist lateral forces from wind.
wind bent
The ease with which concrete can be placed and consolidated in forms.
workability
The maximum unit stress permissible in a structural member.It is also called allowable stress.
working stress
The theory used for most reinforce concrete design until the middle 1960s.
working stress design
slightly above the elastic limit
yield point
The unit stress at which a material deforms with no increase in load
yield point
Two-way shear which occur in a flat slab,spread footing, or pile cap.
punching shear
A type of reinforcement used in reinforced concrete, consisting of a grid of steel wires perpendicular to each other and welded at all pointsof intersection.
welded wire fabric
The level below which the subsoil is saturated with water.Also called the ground water.Also called the ground water level
water table
A method of joining two pieces of metal by heating their surfaces until they are molten or plastic,with or without the use of additional filler material.
welding
A small hole near the bottom of the retaining wall usually backfilled with gravel, to allow water to drain to the outside of the wall and thus avoid hydrostatic preassure against the wall.
weep hole
The side of the building facing the direction from which the wind is blowing.
windward side
A standard designation for a structural steel,wide,flange shape.Also the total dead load used in earthquake design.
W
A flat slab which is ribbed in two directions,resulting in a waffle like appearance.
waffle slab
The speed with which the seismic waves move in a given direction in inch or centimeters per second.
velosity
A length of pipe, running under a road or other barrier, used to drain or carry water.
culvert
Trees having green leaves throughout the year, as opposed to deciduous.
evergreen
Trees which shed leaves annually, as opposed to evergreens.
deciduous
The general pattern of movement of the water on,under, and above the earth.
water cycle
The elevation of the ground surface after completion of all work.
finish grade
The rights to the use or control of the air space above a property.
air rights
The length of a lot line along a street or other public way.
frontage
The right of an owner to have ingress and egress to and from a property.
access right
Clay pipe, usually with open joints, used to convey water away from a footing or to disperse liquid in a septic tank field.
drain tile
A fictitious temperature which would produce the same physiological effect as the combined effects of temperature, humidity, and air movement.
effective temperature
The surface flow of water from an area.
run-off
Describing cone-bearing evergreen trees and shrubs, such as pine, spruce, fir, and cedar.
coniferous
The process by which water vapor escapes into the atmosphere from plants.
transpiration
A parcel of land.
plot
A stone guard to prevent damage to a wall; also a freestanding stone post to divert vehicular traffic.
ballard
The rate of rise or descent of a sloping surface. Also, to remove and/or add earth in order to bring the ground surface to a specified elevation or profile.
grade
Earth that is replaced around a foundation or retaining wall after the concrete forms have been removed.
backfill
A line, usually parallel to a property line, beyond which a structure may not extend.
building line
An ornamental garden arrangement.
parterre
An underground geological formation through which water flows.
aquifer
The expected maximum depth of frost penetration in the ground in a given area.
frost line
The height above a known point of reference, often taken as the height above sea level.
elevation
An approximately level building area.
pad
Earth which is removed (cut) and earth which isadded (fill) in grading.
cut and fill
An underground pipe or drain used to carry off rain water (storm sewer) or waste matter (sanitary sewer).
sewer
A housing pattern in which units face into a common open space.
court pattern
A circumferential or loop roadway around an urban area or development.
ring road
A fictitious temperature assigned to a combination of actual temperature and wind velocity which has the same physiological effect as still air at the wind chill index temperature. It is also known as chill factor.
wind chill index
A pit, usually filled with coarse stone, into which water is conducted for leaching out into surrounding soil.
dry well
An excavated, level terrace in a slope used to collect running water.
bench
The gradual wearing away or disintegration of land caused by water, wind, and so on running over its surface.
erosoion
Structures or plants which, because of their form and location, reduce wind velocities.
windbreak
The lowest point of the inside of a drain, pipe,channel, or other liquid-carrying conduit.
invert
A fictitious temperature assigned to a combination of actual temperature and wind velocity which has the same physiological effect as still air at the chill index factor temperature. It is also known as wind chill index.
chill factor
In surveying, a direction stated in degrees, minutes,and seconds as an angular deviation east or west from due north or south.
bearing
The amount or degree of moisture in an area, a determining element of weather.
humidity
The design and arrangement of natural elements on a site.
landscaping
A public service, such as telephone, water, gas, or electricity.
utility
The natural and manmade things, conditions, and influences surrounding a person, community, or place.
environment
The total horizontal area within the boundary lines of a parcel of land.
lot area
The percentage of total rainfall which is not absorbed in the ground and, hence, runs off. It must be collected in a system of surface and subsurface drains.
runoff coefficient
The climatic characteristics unique to a very small area.
microclimate
The digging or removal of earth.
excavation
The geographic area from which the participants in an activity are drawn, such as the customers of a shopping center or the employees of a manufacturing plant.
catchment
A hole through which a person can enter a sewer,pipe, conduit, and so on for inspection, repair, or ma intena nee.
manhole
The difference of elevation between adjacent contour lines.
contour interval
A belvedere or viewing place.
gazebo
A log showing the types of soil encountered in a test boring and other relevant information.
soil boring log
The minimum distance from the property line into which a structure may not extend.
setback
A flat or level surface.
plane
A sewer for carrying away surface rain water, as opposed to sanitary sewage.
storm sewer
A legal boundary of a parcel of land.
property line
The rate of slope between two points on a surface,determined by dividing their vertical difference in elevation by their horizontal distance apart.
gradient
Removing and/or adding earth in order to bring the ground surface to a specified elevation or profile. Also called grading.
earthwork
The process of determining location, form, and boundaries of a parcel of land by measurement, computation, and drawing.
survey
An open, unoccupied space, other than a court,unobstructed to the sky, on the lot on which a building is situated.
yard
An underground pipe or drain used to carry off waste matter .
sanitary sewer
One or more spaces designated for physically handicapped persons, requiring special design and dimensions.
handicapped parking
A space, open and unobstructed to the sky, located at or above grade, and bounded on three or more sides by the walls of a building
court
A plan of a city or subdivision, showing the boundaries of individual properties.
plat
Space provided for vehicular parking separate from the dedicated street right-of-way.
off-street parking
A very large area of land in which all through traffic is eliminated, but which may be penetrated by cui? de-sacs or minor loop roads.
superblock
The level below which the subsoil is completely saturated with water. Also called the groundwater Level.
water table
Any public way or thoroughfare 10 to 16 feet in width which has been dedicated or deeded to the public for public use.
alley
Flow from a culvert, sewer, or other channel.
discharge
Designing the external physical environment in which buildings and structures are placed.
site planning
The elevation of a specified point on the ground or on a structure.
spot elevation
A pattern of land use which develops along a line, such as a highway or river.
linear pattern
Removing and/or adding earth in order to bring the ground surface to a specified elevation or profile. Also called earthwork.
grading
An imaginary line on the ground surface connecting all points of equal elevation.
contour
A division of urban land, normally private property, which is surrounded by public streets, and which is officially established and recorded.
block
Reflectivity measured as the relative permeability of a surface to radiant energy flowing in either direction.
albedo
Having no environmental barriers, thereby permitting free access and circulation by the handicapped.
barrier-free
A landscaped strip of ground between a pedestrian walk and a street.
planting strip
The net ground area of a lot which can be covered by a building after required setbacks and other zoning limitations have been accounted for.
buildable area
The smallest identifiable parcel of land in a city.
lot
The angle which the sun makes with the horizon.
altitude
The boundary line of a lot.
lot line
The prevailing or average weather conditions of a place as determined over a number of years.
climate
A graded flow path used in open drainage systems.
swale
Concrete used for paving which uses crushed granite as the coarse aggregate.
granolith
A bank of earth, often piled up against a wall.
berm
A horizontal angle measured clockwise from north or south.
azimuth
Paving using crushed stone.
macadam
Inclination or slant, especially of the ground surface.
slope
The extension of a building into the property of another.
encroachment
The intersection of two roads at different levels so that vehicles may move from one road to the other without crossing the stream of traffic. Also called interchange.
grade separation
The amount by which the average outdoor temperature at a particular location is below 65 degrees arenheit for one day. Degree days may also be summed and stated for a month or year.
degree day (dd)
The temperature of air at which the water contained in the air begins to condense and form dew. It is therefore the temperature at which the air is at 100% relative humidity.
dew point
A road or path reserved for bicycle traffic.
bikeway
A horizontal plane elevation used as a reference for other elevations in surveying and mapping.
datum
The land surrounding a flowing stream over which water spreads when a flood occurs.
flood plain
A type of residential siting in which a series of housing units are grouped closely together and surrounded by open space.
cluster
The ratio of the area covered by buildings to the total lot area, expressed as a percentage.
land coverage
Land on which buildings have not yet been constructed, but which contains utilities and streets.
improved land
A partial obstruction against flow, in a duct or pipe.
baffle
The process of controlling, collecting, transporting,and disposing of excess water.
drainage
A sievelike device at the entrance to a storm sewer which traps matter that could block the sewer.
catch basin
A statement, often required by a governmental body, which assesses the environmental impact of a proposed development.
environmental impact
A street, alley, or other thoroughfare or easement permanently established for passage of persons or vehicles.
way
A semicircular open area, with or without a roof, providing a continuous seat.
exedra
The number of degrees north or south of the equator of a point on the earth’s surface.
latitude
The level below which the subsoil is completely saturated with water. Also called the water table.
groundwater level
The study of the total pattern of relations between a community or organisms and its environment.
ecology
The soil layer beneath the topsoil.
subsoil
