Chapter 2 Flashcards
What are forces or other actions that result from the weight of all building materials, occupants and their possessions, environmental effects, movement, etc.
Loads
What are considered ‘permanent loads’?
Dead Loads, Soil, & Hydrostatic
What are ‘variable loads’?
Live Loads & Environmental Loads (wind, snow, rain, earthquake)
_____ loads consist of the weight of materials of construction such as walls, floors, roofs, ceilings, stairways, built-in partitions, finishes etc.
Dead
_____ loads produced by use and occupancy of a building.
Live
When can you NOT use a Live Load Reduction?
Group A Occupancies (assembly)
If live loads exceed 100 psf (except that the design live load for columns may be reduced by 20%)
Basement, foundation, and retaining walls shall be designed to resist ______
Lateral Soil Loads
Factor of Safety
ratio of the ultimate strength of material to its working stress
Breakaway wall
a wall not required to provide structural support that can collapse to allow floodwaters to pass without damage to the structure.
Hydrostatic Loads
Loads caused by water either above or below the ground surface.
Pf
Snow loads on flat roofs
Ce
Exposure Factor
Ct
Thermal Factor
Pg
Ground Snow Load
I
Importance Factor
Basic Wind Speed
3 second gust at 33 ft above the ground in Exposure C
MWFRS
Main Wind Force Resisting System
What elements of the building envelope do not qualify at part of the MWFRS?
Components and Cladding
What is Exposure (in relation to wind) based on?
Ground surface roughness determined by topography, vegetation, and structures.
Surface Roughness B
Urban and Suburban Areas, Wooded Areas, etc.
Surface Roughness C
Open terrain with scattered obstructions (heights less than 30 ft)
Surface Roughness D
Flat, unobstructed areas and water surfaces
A building is considered flexible if the natural frequency is _______
Less than 1 Hz
A building is considered Rigid if the natural frequency is _______
Greater than 1 Hz
What are the three options for evaluating wind loads?
Simplified Procedure, Analytical Procedure, and Wind Tunnel Procedure
What is the internal pressure of an enclosed building?
+/- .18
What is the first type of seismic wave to arrive in the event of an earthquake?
A compression wave
What is the most concerning type of seismic wave?
A Shear wave
The intensity of any earthquake is based on what?
Damage and other observed effects on people, buildings, and other features.
Modified Mercalli Intensity Scale (12 levels of intensities)
The measure of an earthquake strength is ______.
Magnitude
Measure by Richter Magnitude Scale
Minor Earthquakes are categorized by what numbers on the modified mercalli scale?
I - VI
Not felt through slight damage.
Moderate Earthquakes are categorized by what numbers on the modified mercalli scale?
VII & VIII
Damage in some buildings through Considerable Damage in most
Major Earthquakes are categorized by what numbers on the modified mercalli scale?
IX - XII
Damage in majority of buildings through total damage
What is another term for Displacement?
Distance
What is Velocity?
Rate of Change in Distance
What is Acceleration?
Rate of Change in Distance of a period of time
What is Damping?
Process by which vibration diminishes in amplitude
Which is better…
1 story building on rock
or
20 story building on rock
20 story building on rock- There has to be movement somewhere, the building or the soil. A 20 story building will move more than a 1 story building so it can be on rock.
Which is better…
1 story building on deep soil
or
20 story building on deep soil
1 story building on deep soil- There has to be movement somewhere, the building or the soil. A 1 story building won’t move much so the soil needs to be flexible.
A live load reduction can be taken on structural elements only if they support a tributary area of _____ square feet or more.
150
Which of the following are considered impact loads?
- Elevators and Elevator machinery
- Vehicles on garage floors
- Stadium and arena bleacher loading
- Floor hangers supporting machinery
Elevators and Elevator Machinery, and Floor Hangers supporting machinery
T/F Horizontal shear stress is always equal to vertical shear stress
True
A framing system in which the joints are moment connections and allow for unimpeded movement throughout the bays is called a?
Vierendeel Frame
The ability of an element or system to resist gross deformation is known as?
Stability
Name the first four soil site classes (A-D)
A- Hard Rock
B- Rock
C- Very dense soil or soft rock
D- Stiff Soil
What is the best soil class that can be assumed without a geotechnical engineering report?
Site Class D- Stiff Soil
The ability of a system or element to dissipate energy beyond the elastic limit is ____
Ductility
A measure of a systems ductility over strength is called _______
Response modification factor
What are the two design methods for loads that do NOT factor loads?
Allowable Stress Design and Allowable Strength Design
What are the two design methods that factor loads?
Strength Design Method and Load and Resistance Factor Design.
