Chpt 3

Question 1

A ___ is defined as any effect that a structure must resist

Answer 1

Load

Question 2

The impact effect the wind has on a surface. This force may be reduced by streamlining the surfaces encountered.

Answer 2

Direct pressure

Question 3

When wind encounters an object, it’s fluid nature causes it to flow around the object. This exerts a drag effect on the object.

Answer 3

Aerodynamic drag

Question 4

A suction effect produced on the downwind side of the building resulting in an outward pressure

Answer 4

Negative pressure

Question 5

A back and fourth effect due to variations in the velocity of the wind.

Answer 5

Rocking effects

Question 6

Wind passing over a surface such as a roof may cause vibration of the surface depending on the velocity of the wind and the harmonic characteristics of the surface

Answer 6

Vibration

Question 7

The tendency of wind to dislodge objects from a building j

Answer 7

Clean off effect

Question 8

The ____ noted above is of particular concern where a building has projections such as canopies and parapets

Answer 8

Clean off effect

Question 9

The vibrational motion of the surface subjects buildings to forces known as ____ that can be very destructive as history shows

Answer 9

Seismic forces

Question 10

Are produced in a structural member when it is twisted

Answer 10

Torsional forces

Question 11

Are movements of relatively larger amplitude resulting from a small force applied at the natural frequency of a structure

Answer 11

Resonant forces

Question 12

The shifting of the earths surface can also produce forces that are either ______in nature

Answer 12

Torsional or resonant

Question 13

Occurs where the soil is of a loose, sandy nature and is saturated with water.

Answer 13

Soil liquefaction

Question 14

The basic concept of ____ is to isolate the building from the horizontal movement of the earths surface

Answer 14

Base isolation

Question 15

Create a layer between the building and the foundation, which has low horizontal stiffness

Answer 15

Elastomeric bearings

Question 16

Make use of special plates sliding on each other

Answer 16

Sliding systems

Question 17

These systems isolate the building from the horizontal shear force created by an earthquake

Answer 17

Sliding systems

Question 18

Exerts a horizontal pressure against a foundation

Answer 18

Soil

Question 19

The pressure exerted by the soil against the foundation is known as the

Answer 19

Active soil pressure

Question 20

The force of the foundation against the soil is known as the

Answer 20

Passive soil pressure

Question 21

Buildings can also be provided with ____ to control building motion

Answer 21

Damping mechanisms

Question 22

Are typically installed at the connections between columns and beams, and they absorb energy as the structure moves

Answer 22

Damping mechanisms

Question 23

A ____ is the weight of any permanent part of the building

Answer 23

Dead load

Question 24

A ____ is any load that is not fixed or permanent

Answer 24

Live load

Question 25

Is one that is applied at one point or over a small area

Answer 25

Concentrated load

Question 26

Water from fire fighting operations can add an additional _____

Answer 26

Live load

Question 27

A stream of water discharging 250 gpm introduces ______ of water per minute

Answer 27

2082 pounds of water per minute

Question 28

A water depth of 3 inches will impose a load of ___ per square foot

Answer 28

20.8 pounds

Question 29

Are loads that are steady or are applied gradually

Answer 29

Static loads

Question 30

Are loads that involve motion

Answer 30

Dynamic loads

Question 31

When the support provided by a structural system is equal to the applied loads, a condition known as ____ exists

Answer 31

Equilibrium

Question 32

The forces that resist the applied loads are known as

Answer 32

Reactions

Question 33

A beam that is supported at one end is known as a

Answer 33

Cantilever beam

Question 34

Tends to pull the material apart

Answer 34

Tension

Question 35

Tends to squeeze the material

Answer 35

Compression

Question 36

Tends to slide one plane of a material past an adjacent plane

Answer 36

Shear

Question 37

The magnitude of the interior forces that occur in structural members is evaluated by a quantity known as

Answer 37

Stress

Question 38

Can also be classified as axial, eccentric, or torsional

Answer 38

Exterior loads

Question 39

An ____ is a load applied to the center of the cross section of a structural member and perpendicular to that cross section

Answer 39

Axial load

Question 40

An ___ is a load that is perpendicular to the cross section of the structural member but does not pass through the center of the cross section.

Answer 40

Eccentric load

Question 41

A ___ is offset from the center of the cross section of the structural member and at an angle to or in the same plane as the cross section.

Answer 41

Torsional load

Question 42

A ____ produces a twisting effect that creates shear stresses in a material

Answer 42

Torsional load

Question 43

A ___ is a structural member that can carry loads perpendicular to its longitudal dimension

Answer 43

Beam

Question 44

The primary design consideration of____ is their ability to resist bending from the applied loads

Answer 44

Beams

Question 45

At the middle of the beam, a point known as the ____, the tension and compression stresses are actually zero

Answer 45

Neutral axis

Question 46

Are structural members designed to support an axial compressive load.

Answer 46

Columns

Question 47

An ___ is a curved structural member in which the interior stresses are primarily compressive

Answer 47

Arch

Question 48

Can be thought of as flexible structural members that can be used to support roofs, brace tents, and restrain pneumatic structures

Answer 48

Cables

Question 49

Although cables can be used in applications where they are essentially straight, a cable used to support loads over a distance will assume the shape of a

Answer 49

Parabola

Question 50

Are framed structural units made up of a group of triangles in one plane

Answer 50

Trusses

Question 51

The top members of a truss are called the

Answer 51

Top chords

Question 52

The bottom members of a truss are called

Answer 52

Bottom chords

Question 53

Lightweight wood or metal trusses, known as _____, have become very common in floor construction, taking the place of solid joists

Answer 53

Truss joists

Question 54

Are truss structures that are developed in three dimensions

Answer 54

Space frames

Question 55

A common method of construction uses the walls of the building to support spanning elements such as beams, trusses, and precast concrete slabs. These are appropriately known as______structures

Answer 55

Bearing wall structures

Question 56

Uses a series of vertical elements to support horizontal elements that are subject to traverse loads

Answer 56

Post and beam

Question 57

Typical dimensions for the posts are_____ when supporting roofs only

Answer 57

6x8 inches post and beam construction