NCEES Structural Engineering PE Exam 2 — Questions and Answers
Question 1: On the NCEES PE Structural exam, which parameter defines the seismic design category (SDC) of a structure?
- Wind speed and building height only
- Spectral response accelerations and occupancy category (Correct answer)
- Soil type and foundation depth only
- Geographic location and material type
Correct answer: Spectral response accelerations and occupancy category
The seismic design category is determined by combining the mapped spectral response accelerations (SDS and SD1) with the risk category (occupancy) of the structure.
Question 2: In NCEES PE Structural exam problems, what does the 'response modification factor R' represent in seismic design?
- The ratio of elastic to inelastic seismic forces, reflecting ductility and overstrength (Correct answer)
- The amplification of wind loads near coastal areas
- The soil amplification factor
- The redundancy factor for lateral systems
Correct answer: The ratio of elastic to inelastic seismic forces, reflecting ductility and overstrength
The R factor reduces the elastic seismic demand to a design-level force by accounting for the inherent ductility, overstrength, and energy dissipation of the structural system.
Question 3: For the NCEES PE Structural exam, what is the primary purpose of confining reinforcement (hoops/spirals) in a concrete column?
- To resist longitudinal tension
- To increase ductility and concrete confinement under compression (Correct answer)
- To prevent corrosion of main bars
- To transfer shear forces to footings
Correct answer: To increase ductility and concrete confinement under compression
Transverse confinement reinforcement increases concrete ductility and compressive strength by restraining lateral expansion of the core concrete under axial load.
Question 4: On the NCEES PE Structural exam, what is a 'diaphragm' in building structural engineering?
- A flexible joint between foundation and superstructure
- A horizontal structural element that distributes lateral forces to vertical elements (Correct answer)
- A vertical bracing panel
- A type of beam-column connection
Correct answer: A horizontal structural element that distributes lateral forces to vertical elements
A diaphragm (floor or roof system) acts as a horizontal plate that collects and distributes lateral forces to the building's shear walls, frames, or braces.
Question 5: In NCEES PE Structural exam problems, which ACI 318 equation governs the nominal shear strength provided by concrete in a beam?
- Vc = 2√f'c × bw × d (simplified) (Correct answer)
- Vc = 0.85f'c × Ag
- Vc = fy × Av × s / d
- Vc = 1.2f'c × bw × h
Correct answer: Vc = 2√f'c × bw × d (simplified)
The simplified ACI 318 equation for concrete shear contribution is Vc = 2√f'c × bw × d (in US customary units), where bw is web width and d is effective depth.
Question 6: For the NCEES PE Structural exam, what does 'live load reduction' allow engineers to do?
- Ignore wind loads on interior columns
- Reduce design live loads for large tributary areas based on probability (Correct answer)
- Use lower safety factors for residential buildings
- Reduce seismic forces in low-hazard zones
Correct answer: Reduce design live loads for large tributary areas based on probability
Live load reduction permits lower design live loads on members with large tributary areas, since it is statistically unlikely that the full code live load acts simultaneously over a large area.
NCEES Structural Engineering PE Exam 2
On the NCEES PE Structural exam, which parameter defines the seismic design category (SDC) of a structure?