Structural Design and Loads: Deterministic Load Paths
Loads a candidate must know
Structural provisions define dead, live, snow, wind, seismic, rain, and soil loads, and the load combinations used to design members. Understand the difference between nominal (unfactored) and factored loads, serviceability limits (deflection, vibration), and the required load path from roof to foundation. Know that live-load reductions are permitted only within the code's limits and never for places of public assembly above a threshold. Structural observation, special inspection, and testing requirements attach to certain materials and systems.
Structural integrity and fire
Large buildings require attention to structural integrity provisions: continuity, anchorage, and connection detailing that prevent disproportionate collapse. Fire-resistance of structural members is a structural and fire-protection interface; the required rating depends on construction type and occupancy. Also understand that alterations affecting structural capacity require analysis by a qualified design professional and documentation.
Traps
- Applying live-load reductions to assembly occupancies where the code forbids them.
- Confusing nominal and factored values in a question about load combinations.
- Forgetting that seismic and wind provisions are not interchangeable; the governing one depends on site and building characteristics.
- Overlooking special inspection requirements for certain connections and materials.
Rule of thumb
For any load question, identify the load type, whether it is nominal or factored, and which combination applies. If a number is offered without a combination, the question is likely about nominal values.
Worked example
A proposed column carries roof and floor loads. The candidate must select the governing load combination from the code, apply permitted live-load reductions only where allowed, and confirm the member's fire-resistance rating matches the construction type. Answers that skip the fire rating are incomplete.