BOMI Desin & Oper Ch. 4

Question 1

Most common causes of building collapse:

Answer 1

Bad design; faulty construction; foundation; extraordinary loads

Question 2

Dead loads

Answer 2

Permanent loads on the structure. Include the weight of structural members and all attachments that remain throughout the life of the building, pipes, electrical conduits, HVAC, lighting fixtures, flooring, permanent partitions, suspended ceilings, and roofing

Question 3

Live loads

Answer 3

Move on and off the structure and vary in magnitude and location. Make it difficult to estimate the magnitudes and positions of these loads. (Occupants, furnishings, machinery, movable partitions, rain, snow and ice.)

Question 4

Loads unique to geographical regions:

Answer 4

Snow loads; Wind loads (3-4 stories high require special wind force consideration); Seismic Loads (earthquakes); Vibration Loads (caused by heavy traffic, trains, subways, heavy trucks); Shock Loads (load suddenly applied to a structure)

Question 5

Stress

Answer 5

Load per unit of area and is measured in pounds per square inch (psi).

Question 6

Tensile stress

Answer 6

Tension, magnitude of tension (stretching a material_

Question 7

Compressive Stress

Answer 7

Stress applied to materials, resulting in a compaction, or decrease of volume. Long structural elements (columns) w/aspect ratios greater than 2:1 will buckle when compressive stress is increased due to elastic instability.

Question 8

Shear Stress

Answer 8

Is the magnitude of shear in a structural member. Slipping tendency along a plane in a material caused y parallel but opposite forces applied to the two sides of the plane.

Question 9

Cellular Steel floor system

Answer 9

Used in office buildings, hotels, and apartment buildings. Made of cellular panels consisting of light-gauge galvanized or painted sheet steel.

Question 10

Composite steel floor

Answer 10

Consist of a steel deck bonded w/a concrete slab, so the two act as a unit in resisting the total loads. (Cracks can form, so place reinforcing bars)

Question 11

Open Web Joist floor

Answer 11

Well-suited to buildings intended for comparatively light floor loads not subject to vibration or heavy concentrations. (steel bar joists made from bars, small angles, or other steel shapes_

Question 12

Loadbearing walls

Answer 12

Carry the ceiling (roof or upper floor loads to the foundation oar loadbearing). Most common in single-story, residential, and light commercial construction.

Question 13

Nonloadbearing walls

Answer 13

Used as partitions or dividers

Question 14

Curtain wall

Answer 14

Exterior building wall of any material that is hung on the external structure and carries no vertical loads

Question 15

Interior walls

Answer 15

Loadbearing interior walls are permanent walls built to be strong and are excellent fire walls

Question 16

Composite columns

Answer 16

Steel column shapes surrounded by and bonded to reinforced concrete

Question 17

Friction piles

Answer 17

Load transfer to the soil is accomplished by shearing forces, or friction, on the sides of the piles.

Question 18

End-bearing piles

Answer 18

With deep rock, the pile load can also be transferred directly from the end of the pile to the rock.

Question 19

Floating foundations

Answer 19

Made of concrete heavily reinforced w/steel, so entire foundation will act as a unit.

Question 20

Maintaining Steel

Answer 20

Regular inspections and cleaning are more important than repainting.

Question 21

Spalling

Answer 21

Breaking off of pieces of concrete due to the pressure created by moisture freezing w/in the concrete.

Question 22

1) The designer had to make special considerations for wind as the building was taller than ______ stores, the minimum height that usually necessitates such consideration. a-1 or 2; b-3 or 4; c-5 or 6; d-7 or 8

Answer 22

b-3 or 4

Question 23

2) The type of stress an upper floor places on the columns that support it is ______ stress. a-tensile; b-compressive; c-cohesive; d-shear

Answer 23

b-compressive

Question 24

3) Compared w/steel and concrete decks, all of the following are characteristics of a wood floor system except: a-shorter spans; b-less fire resistance; c-more dimensional stability; d-lower cost

Answer 24

c-more dimensional stability (They offer less dimensional stability.)

Question 25

4) Most ______ are erected using a combination of reinforced concrete and structural steel to achieve composite columns and avoid constructing extremely large columns on the lower floors, which take up valuable space. a-field houses; b-low rise buildings; c-high rise buildings; d-single story buildings

Answer 25

c-high-rise buildings

Question 26

5) Bill may select steel for construction of his new building due to its ability to last indefinitely, and under proper conditions, require little painting maintenance. This is an example of the advantage of ______ when using steel for construction. a-high strength; b-uniformity; c-elasticity; d-permanence

Answer 26

d-permanence

Question 27

6) Bill has decided to choose precast concrete rather than reinforced concrete for construction of his new building. In doing so, he hopes to achieve greater independence of construction from weather conditions. Another advantage of using precast concrete is found in the: a-floor to floor heights; b-quality control and concrete strength; c-continuity between structural members; d-heavier weight that increases the size of the foundation

Answer 27

b-quality control and concrete strength

Question 28

Precast concrete

Answer 28

Reinforced concrete that is cast and hardened into desired shapes away from the building site.

Question 29

Reinforced concrete

Answer 29

steel rods or bars supply reinforcement because of their high tensile strength. Poured on-site. Combine many advantages of concrete and steel.

Question 30

7) Sheila, the building manager, has noticed a large crack between a concrete terrace and its retaining wall after a harsh winter. This most likely is an indication of a problem w/the foundation soil and ______. a-frost; b-nutrients; c-shifting; d-moisture

Answer 30

a-frost

Question 31

8) A shallow foundation system may use ______ for the building foundation to support load-bearing walls located on average to good loadbearing capacity soil, as well as boundary and retaining walls. a-steel piles; b-spread footing systems; c-mat and raft systems; d-floating sytems

Answer 31

b-spread footing systems

Question 32

Shallow Systems

Answer 32

Most economical type if the soil near the ground surface has adequate loadbearing capacity (Spread footing systems and mat and raft systems).

Question 33

Spread footing systems

Answer 33

generally square blocks of concrete. Support load-transmitting elements such as walls, pilasters, columns, or piers.

Question 34

Mat and Raft systems

Answer 34

used over soils of low loadbearing capacity when other foundations are inadequate or when spread footing sizes become so large that hey impinge on each other.

Question 35

9) The inspection team noted a general decay of the concrete surface involving loss of the cement paste, resulting in the loosening of the aggregate. This is an example of ______. a-cracking; b-spalling; c-disintegration; d-corrosion

Answer 35

c-disintegration

Question 36

Disintgegration

Answer 36

General decay of the concrete surface involving loss of the cement paste and loosening of the coarse aggregate.