Free PE Civil: Structural Practice Questions

Sample Practice Questions

Try these 10 sample questions from the PE Civil: Structural practice bank. Each includes the answer and explanation. Continue with the interactive practice above to review the full question set.

1. 1An engineer separates the loads on a completed residential floor into dead and live loads. Which load belongs in the dead-load calculation?

   1. A. The weight of movable office desks
   2. B. The weight of permanently fixed equipment
   3. C. The weight of stored maintenance supplies
   4. D. The weight of the building occupants

   Answer: B

   Explanation: HUD includes "claddings, finishes, and fixed equipment" in dead loads. Permanently fixed equipment contributes dead load; occupants, movable furnishings, and stored supplies contribute live load.

   Reference: HUD Residential Structural Design Guide, Second Edition — Section 3.3, p. 3-4

2. 2A bridge engineer constructs a qualitative bending-moment influence line at an interior section using the Müller-Breslau principle. Which release is introduced at that section?

   1. A. An axial slip with bending and shear continuity
   2. B. A vertical slip with bending and axial continuity
   3. C. A hinge with axial and shear continuity
   4. D. A torsional release with bending and axial continuity

   Answer: C

   Explanation: FHWA specifies "introduce a hinge" while "maintaining axial and shear force resistance." This releases the moment being investigated. Axial slip, vertical slip, and torsional release correspond to other response components.

   Reference: FHWA LRFD for Highway Bridge Superstructures Reference Manual — Section 4.4.3.1, p. 4.53

3. 3A federal structural project incorporates UFGS 01 45 35 and requires continuous special inspection of an operation. The operation runs without pauses from 08:15 to 11:45 on the same day. What minimum duration of inspection coverage must be provided for this operation?

   1. A. 2.50 hours
   2. B. 3.30 hours
   3. C. 3.50 hours
   4. D. 4.00 hours

   Answer: C

   Explanation: The specification states, "Continuous Special Inspections is the constant monitoring of specific tasks by a special inspector. These inspections must be carried out continuously over the duration of the particular tasks." The full uninterrupted interval is 3 hours 30 minutes, or 3.50 hours. The alternatives lose an hour in borrowing, subtract clock readings as decimal hours, or add rather than subtract the minute portions. Coverage must span the operation; the question asks for the minimum duration.

   Reference: Unified Facilities Guide Specifications 01 45 35—Special Inspections — Paragraph 1.3.1, Continuous Special Inspections

4. 4A geotechnical laboratory reports that a soil specimen weighs 120 g before drying and 100 g after oven drying. What gravimetric water content should the engineer use?

   1. A. 16.7%
   2. B. 20.0%
   3. C. 83.3%
   4. D. 120.0%

   Answer: B

   Explanation: The source states, "w= Ww x100 Ws 2-4" The printed fraction is water weight divided by solids weight, multiplied by 100. Water weight is 120−100=20 g and solids weight is 100 g, giving 20%.

   Reference: FHWA Soils and Foundations Reference Manual, Volume I — Section 2.1.2, p. 2-5, Equation 2-4a

5. 5A residential built-up wood girder uses several nailed lumber plies with butt joints. Which joint layout follows the load-sharing detail described in HUD's design guidance?

   1. A. Align all ply joints at or near supports
   2. B. Stagger ply joints at or near supports
   3. C. Align all ply joints near midspan
   4. D. Stagger ply joints near midspan

   Answer: B

   Explanation: The source states, "The built-up member can resist higher loads only if butt joints are located at or near supports and are staggered in alternate plies." All four arrangements are distinct combinations of actual joint positions and alignment. The source requires both support proximity and staggering for the stated load-sharing detail.

   Reference: HUD Residential Structural Design Guide, Second Edition — Section 5.4.3, p. 5-28, Built-up Beams

6. 6For a residential floor dead-load takeoff, an engineer specifies a 6-in.-thick solid concrete slab with a unit weight of 150 lb/ft³. What is the slab self-weight per square foot, excluding finishes?

   1. A. 12.5 lb/ft²
   2. B. 150 lb/ft²
   3. C. 75 lb/ft²
   4. D. 900 lb/ft²

   Answer: C

   Explanation: HUD notes that material densities are useful "in calculating dead loads more accurately." Multiplying 150 lb/ft³ by 6/12 ft gives 75 lb/ft². The other results omit the 6-in. thickness, treat it as one foot, or omit the inch-to-foot conversion.

   Reference: HUD Residential Structural Design Guide, Second Edition — Section 3.3, p. 3-4

7. 7A bridge bearing opens and closes as a moving load changes position. Which analysis treatment preserves that load-dependent support contact?

   1. A. Use a linear influence line with that bearing active at every position.
   2. B. Use a linear influence line with that bearing inactive at every position.
   3. C. Use a nonlinear analysis that updates bearing contact at each position.
   4. D. Use a linear influence line with averaged bearing stiffness at every position.

   Answer: C

   Explanation: The source states, "the influence line method is inappropriate because the stiffness of the support is non-linear." Active, inactive and averaged linear restraints are genuine idealizations, but none captures the changing contact. The actual opening/closing support requires nonlinear treatment.

   Reference: FHWA LRFD for Highway Bridge Superstructures Reference Manual — Section 4.4.3.1, p. 4.51

8. 8An engineer reviews a proposed structural special inspector for a federal project that incorporates the third-party requirement of UFGS 01 45 35. Which employment relationship satisfies that independence requirement?

   1. A. An employee of the reinforcing-steel installation subcontractor
   2. B. An employee of the prime contractor's quality-control department
   3. C. An employee of the structural-steel erection subcontractor
   4. D. An independent inspection professional retained by the prime contractor

   Answer: D

   Explanation: The specification requires an "independent third party hired directly by the Prime Contractor" and prohibits employment by the contractor or subcontractor performing the inspected work. Independent retention meets the requirement; the three contractor-employee relationships do not.

   Reference: Unified Facilities Guide Specifications 01 45 35—Special Inspections — Paragraphs 1.3.4 and 1.3.6

9. 9At a saturated foundation-soil point, total vertical stress is 150 kPa and pore-water pressure is 60 kPa. What vertical effective stress controls the intergranular stress calculation?

   1. A. 210 kPa
   2. B. 150 kPa
   3. C. 60 kPa
   4. D. 90 kPa

   Answer: D

   Explanation: FHWA states, "The effective stress is the total stress minus the pore water pressure." Thus σ′ = 150 − 60 = 90 kPa. Adding the pressures or using either component alone does not give effective stress.

   Reference: FHWA Soils and Foundations Reference Manual, Volume I — Section 2.2, p. 2-19, Equation 2-13

10. 10An ASD check of a simply supported 20-ft wood floor joist starts from a uniform-load span table. Existing uniform service loads produce 2 kip-ft of midspan moment. A new 2-kip service equipment load acts at midspan and is carried entirely by this joist. With 11 kip-ft allowable moment capacity, what total midspan moment and moment-capacity result follow?

    1. A. 2 kip-ft; within capacity
    2. B. 7 kip-ft; within capacity
    3. C. 12 kip-ft; exceeds capacity
    4. D. 22 kip-ft; exceeds capacity

    Answer: C

    Explanation: HUD states, "Joist spans are set using only uniform dead and live loads; no concentrated loads are included." Its point-load diagram gives "Pab Mmax (at point of load) = L" The stacked fraction is Mmax=Pab/L. Here a=b=10 ft, so the added moment is 2(10)(10)/20=10 kip-ft. Total midspan moment is 2+10=12 kip-ft, exceeding 11. The alternatives omit the equipment moment, use PL/8, or use PL/2.

    Reference: HUD Residential Structural Design Guide, Second Edition — p. 5-26, Floor Joists: span-table loading assumptions