Architecture and Design Structural Systems 2 — Questions and Answers
Question 1: What is the purpose of a moment frame in structural engineering?
- To resist gravity loads only
- To resist lateral loads through rigid beam-column connections (Correct answer)
- To distribute tributary loads to footings
- To provide a path for vertical loads to skip over openings
Correct answer: To resist lateral loads through rigid beam-column connections
A moment frame resists lateral forces through bending in beams and columns connected with moment-resisting (rigid) joints.
Question 2: What does 'tributary area' mean in structural design?
- The total floor area of the building
- The area of floor or roof that contributes loads to a specific structural member (Correct answer)
- The area around a column that must be reinforced for punching shear
- The watershed area for roof drainage design
Correct answer: The area of floor or roof that contributes loads to a specific structural member
Tributary area is the portion of a floor or roof slab assigned to a particular beam, column, or wall for load calculation purposes.
Question 3: A flat plate structural system in a concrete building is characterized by:
- Beams in both directions supporting the slab
- A slab supported directly by columns with no beams or drop panels (Correct answer)
- A slab with thickened areas (drop panels) around columns
- A one-way slab spanning between parallel beams
Correct answer: A slab supported directly by columns with no beams or drop panels
A flat plate is a two-way reinforced concrete slab of uniform thickness supported directly by columns with no beams or capitals.
Question 4: In seismic design, the concept of 'base isolation' involves:
- Anchoring the building rigidly to the foundation
- Placing flexible isolators between the foundation and structure to decouple seismic motion (Correct answer)
- Building below grade to avoid surface ground motion
- Stiffening the building to resist seismic forces
Correct answer: Placing flexible isolators between the foundation and structure to decouple seismic motion
Base isolation systems use flexible bearings or pads to isolate the building from ground motion, significantly reducing seismic forces transmitted to the structure.
Question 5: Which structural system is most efficient for high-rise buildings above 40 stories?
- Rigid frame only
- Bearing wall system
- Tube structure (framed tube or bundled tube) (Correct answer)
- Flat slab without shear walls
Correct answer: Tube structure (framed tube or bundled tube)
Tube systems concentrate structural material at the perimeter, creating efficient resistance to lateral loads at great heights.
Question 6: What does 'dead load' refer to in structural design?
- The weight of temporary construction equipment
- The permanent weight of the building's own structure and fixed components (Correct answer)
- Wind and seismic forces
- The weight of occupants and furnishings
Correct answer: The permanent weight of the building's own structure and fixed components
Dead loads are permanent, static loads from the building's own weight including structure, finishes, and fixed mechanical equipment.
Architecture and Design Structural Systems 2
What is the purpose of a moment frame in structural engineering?