Structural Systems Flashcards
resonance
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 building’s earthquake induced forces and deformations must be considered in the design.
bearing capacity
The load per unit area which can be safely supported by the ground.
column
A member, usually vertical, which is subject primarily to axial compressive load.
amplification
An increase in a building’s response to earthquake
ground motion, resulting from the building’s period coinciding with that of the ground shaking, or other causes.
continuous beam
A beam that rests on more than two supports.
compression
Stress which tends to shorten a member or crush it.
in situ
In place.
pile cap
A thick, reinforced concrete slab placed over a group of piles and used to distribute the structural
load to all the piles in the group.
vertical shear (v)
The algebraic sum of the forces that are on one side of a given cross-section of a beam.
component
One of two or more forces which will produce the same effect on a body as a given force.
deflection
The movement of a beam from its original location when load is applied to it.
centroid
The point in a cross-section where all of the area may be considered concentrated without affecting the moment of the area about any axis. For symmetrical shapes, the centroid is the geometric center of the shape.
rigid frame
A frame with rigid joints, in which members and joints are capable of resisting vertical and
horizontal forces primarily by flexure. It is also called a moment-resisting frame.
p-delta effect
The secondary effect on frame members produced by vertical loads acting on a building frame which is laterally displaced by earthquake loads.
caisson
A waterproof box-like structure in which construction work can be performed underwater.
Also a pile constructed by pouring concrete into a drilled shaft.
construction joint
The joint between two successive concrete pours. Construction joints are usually located where the shear is minimum, such as at the midspan of beams.
thrust
The horizontal reaction at the base of an arch.
fill
A manmade deposit of soil.
working stress
The maximum unit stress permissible in a structural member. It is also called allowable stress.
volume factor
A factor used to reduce the allowable bending stress for glued, laminated beams, based on width, depth, and span.
coefficient off riction
The ratio of the maximum frictional force between
two bodies to the normal (perpendicular) for pressing the surfaces together.
moment
The tendency of a force to cause rotation about a given point or axis.
coefficient of thermal expansion
The ratio of unit strain to temperature change, which is constant for a given material.
concentric braced frame
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.